diff --git a/components/layout/construct.rs b/components/layout/construct.rs
index 072413995b2f..856f8dbc52e1 100644
--- a/components/layout/construct.rs
+++ b/components/layout/construct.rs
@@ -1847,6 +1847,10 @@ where
             node.type_id()
         );
 
+        // FIXME(emilio): This should look at display-outside and
+        // display-inside, but there's so much stuff that goes through the
+        // generic "block" codepath (wrongly).
+        //
         // Switch on display and floatedness.
         match (display, float, positioning) {
             // `display: none` contributes no flow construction result.
@@ -1871,12 +1875,6 @@ where
                 self.set_flow_construction_result(node, construction_result)
             },
 
-            // List items contribute their own special flows.
-            (Display::ListItem, float_value, _) => {
-                let construction_result = self.build_flow_for_list_item(node, float_value);
-                self.set_flow_construction_result(node, construction_result)
-            },
-
             // Inline items that are absolutely-positioned contribute inline fragment construction
             // results with a hypothetical fragment.
             (Display::Inline, _, Position::Absolute) |
@@ -1958,7 +1956,12 @@ where
             // properties separately.
             (_, float_value, _) => {
                 let float_kind = FloatKind::from_property(float_value);
-                let construction_result = self.build_flow_for_block(node, float_kind);
+                // List items contribute their own special flows.
+                let construction_result = if display.is_list_item() {
+                    self.build_flow_for_list_item(node, float_value)
+                } else {
+                    self.build_flow_for_block(node, float_kind)
+                };
                 self.set_flow_construction_result(node, construction_result)
             },
         }
diff --git a/components/layout/generated_content.rs b/components/layout/generated_content.rs
index 683bb316897f..d69ddd659911 100644
--- a/components/layout/generated_content.rs
+++ b/components/layout/generated_content.rs
@@ -19,7 +19,6 @@ use crate::traversal::InorderFlowTraversal;
 use script_layout_interface::wrapper_traits::PseudoElementType;
 use smallvec::SmallVec;
 use std::collections::{HashMap, LinkedList};
-use style::computed_values::display::T as Display;
 use style::computed_values::list_style_type::T as ListStyleType;
 use style::properties::ComputedValues;
 use style::selector_parser::RestyleDamage;
@@ -175,7 +174,7 @@ impl<'a, 'b> ResolveGeneratedContentFragmentMutator<'a, 'b> {
         }
 
         let mut list_style_type = fragment.style().get_list().list_style_type;
-        if fragment.style().get_box().display != Display::ListItem {
+        if !fragment.style().get_box().display.is_list_item() {
             list_style_type = ListStyleType::None
         }
 
@@ -291,7 +290,7 @@ impl<'a, 'b> ResolveGeneratedContentFragmentMutator<'a, 'b> {
 
     fn reset_and_increment_counters_as_necessary(&mut self, fragment: &mut Fragment) {
         let mut list_style_type = fragment.style().get_list().list_style_type;
-        if !self.is_block || fragment.style().get_box().display != Display::ListItem {
+        if !self.is_block || !fragment.style().get_box().display.is_list_item() {
             list_style_type = ListStyleType::None
         }
 
diff --git a/components/style/font_face.rs b/components/style/font_face.rs
index 50814c5f5e8b..d45cd340c858 100644
--- a/components/style/font_face.rs
+++ b/components/style/font_face.rs
@@ -414,16 +414,10 @@ impl Parse for Source {
 
 macro_rules! is_descriptor_enabled {
     ("font-display") => {
-        unsafe {
-            use crate::gecko_bindings::structs::mozilla;
-            mozilla::StaticPrefs::sVarCache_layout_css_font_display_enabled
-        }
+        static_prefs::pref!("layout.css.font-display.enabled")
     };
     ("font-variation-settings") => {
-        unsafe {
-            use crate::gecko_bindings::structs::mozilla;
-            mozilla::StaticPrefs::sVarCache_layout_css_font_variations_enabled != 0
-        }
+        static_prefs::pref!("layout.css.font-variations.enabled")
     };
     ($name:tt) => {
         true
diff --git a/components/style/gecko/media_queries.rs b/components/style/gecko/media_queries.rs
index 556470569dba..bb126e16948f 100644
--- a/components/style/gecko/media_queries.rs
+++ b/components/style/gecko/media_queries.rs
@@ -213,12 +213,11 @@ impl Device {
             None => return MediaType::screen(),
         };
 
-        // Gecko allows emulating random media with mIsEmulatingMedia and
-        // mMediaEmulated.
-        let medium_to_use = if pc.mIsEmulatingMedia() != 0 {
-            pc.mMediaEmulated.mRawPtr
+        // Gecko allows emulating random media with mMediaEmulationData.mMedium.
+        let medium_to_use = if !pc.mMediaEmulationData.mMedium.mRawPtr.is_null() {
+            pc.mMediaEmulationData.mMedium.mRawPtr
         } else {
-            pc.mMedium
+            pc.mMedium as *const structs::nsAtom as *mut _
         };
 
         MediaType(CustomIdent(unsafe { Atom::from_raw(medium_to_use) }))
@@ -253,9 +252,8 @@ impl Device {
             None => return Scale::new(1.),
         };
 
-        let override_dppx = pc.mOverrideDPPX;
-        if override_dppx > 0.0 {
-            return Scale::new(override_dppx);
+        if pc.mMediaEmulationData.mDPPX > 0.0 {
+            return Scale::new(pc.mMediaEmulationData.mDPPX);
         }
 
         let au_per_dpx = pc.mCurAppUnitsPerDevPixel as f32;
@@ -270,8 +268,7 @@ impl Device {
         if doc.mIsBeingUsedAsImage() {
             return true;
         }
-        let document_color_use =
-            unsafe { structs::StaticPrefs::sVarCache_browser_display_document_color_use };
+        let document_color_use = static_prefs::pref!("browser.display.document_color_use");
         let prefs = self.pref_sheet_prefs();
         match document_color_use {
             1 => true,
diff --git a/components/style/gecko/pseudo_element.rs b/components/style/gecko/pseudo_element.rs
index 501611830ffd..aa849ceee024 100644
--- a/components/style/gecko/pseudo_element.rs
+++ b/components/style/gecko/pseudo_element.rs
@@ -187,9 +187,7 @@ impl PseudoElement {
             PseudoElement::FirstLine => PropertyFlags::APPLIES_TO_FIRST_LINE,
             PseudoElement::Placeholder => PropertyFlags::APPLIES_TO_PLACEHOLDER,
             PseudoElement::Cue => PropertyFlags::APPLIES_TO_CUE,
-            PseudoElement::Marker
-                if unsafe { structs::StaticPrefs::sVarCache_layout_css_marker_restricted } =>
-            {
+            PseudoElement::Marker if static_prefs::pref!("layout.css.marker.restricted") => {
                 PropertyFlags::APPLIES_TO_MARKER
             },
             _ => return None,
diff --git a/components/style/gecko/pseudo_element_definition.mako.rs b/components/style/gecko/pseudo_element_definition.mako.rs
index 562b4c184444..d8d80d601652 100644
--- a/components/style/gecko/pseudo_element_definition.mako.rs
+++ b/components/style/gecko/pseudo_element_definition.mako.rs
@@ -112,7 +112,7 @@ impl PseudoElement {
             % for pseudo in PSEUDOS:
                 ${pseudo_element_variant(pseudo)} =>
                 % if pseudo.is_tree_pseudo_element():
-                    if unsafe { structs::StaticPrefs::sVarCache_layout_css_xul_tree_pseudos_content_enabled } {
+                    if static_prefs::pref!("layout.css.xul-tree-pseudos.content.enabled") {
                         0
                     } else {
                         structs::CSS_PSEUDO_ELEMENT_ENABLED_IN_UA_SHEETS_AND_CHROME
@@ -209,9 +209,7 @@ impl PseudoElement {
                 if starts_with_ignore_ascii_case(name, "-moz-tree-") {
                     return PseudoElement::tree_pseudo_element(name, Box::new([]))
                 }
-                if unsafe {
-                    structs::StaticPrefs::sVarCache_layout_css_unknown_webkit_pseudo_element
-                } {
+                if static_prefs::pref!("layout.css.unknown-webkit-pseudo-element") {
                     const WEBKIT_PREFIX: &str = "-webkit-";
                     if starts_with_ignore_ascii_case(name, WEBKIT_PREFIX) {
                         let part = string_as_ascii_lowercase(&name[WEBKIT_PREFIX.len()..]);
diff --git a/components/style/gecko/selector_parser.rs b/components/style/gecko/selector_parser.rs
index 1da352249d4c..2aad41adc9c0 100644
--- a/components/style/gecko/selector_parser.rs
+++ b/components/style/gecko/selector_parser.rs
@@ -5,7 +5,7 @@
 //! Gecko-specific bits for selector-parsing.
 
 use crate::element_state::{DocumentState, ElementState};
-use crate::gecko_bindings::structs::{self, RawServoSelectorList};
+use crate::gecko_bindings::structs::RawServoSelectorList;
 use crate::gecko_bindings::sugar::ownership::{HasBoxFFI, HasFFI, HasSimpleFFI};
 use crate::invalidation::element::document_state::InvalidationMatchingData;
 use crate::selector_parser::{Direction, SelectorParser};
@@ -170,13 +170,10 @@ impl NonTSPseudoClass {
 
     /// Returns whether the pseudo-class is enabled in content sheets.
     fn is_enabled_in_content(&self) -> bool {
-        use crate::gecko_bindings::structs::mozilla;
         match *self {
             // For pseudo-classes with pref, the availability in content
             // depends on the pref.
-            NonTSPseudoClass::Fullscreen => unsafe {
-                mozilla::StaticPrefs::sVarCache_full_screen_api_unprefix_enabled
-            },
+            NonTSPseudoClass::Fullscreen => static_prefs::pref!("full-screen-api.unprefix.enabled"),
             // Otherwise, a pseudo-class is enabled in content when it
             // doesn't have any enabled flag.
             _ => !self
@@ -354,8 +351,7 @@ impl<'a, 'i> ::selectors::Parser<'i> for SelectorParser<'a> {
 
     #[inline]
     fn parse_part(&self) -> bool {
-        self.chrome_rules_enabled() ||
-            unsafe { structs::StaticPrefs::sVarCache_layout_css_shadow_parts_enabled }
+        self.chrome_rules_enabled() || static_prefs::pref!("layout.css.shadow-parts.enabled")
     }
 
     fn parse_non_ts_pseudo_class(
diff --git a/components/style/lib.rs b/components/style/lib.rs
index 587b926efc6c..35070b0f2546 100644
--- a/components/style/lib.rs
+++ b/components/style/lib.rs
@@ -91,6 +91,8 @@ extern crate servo_config;
 extern crate servo_url;
 extern crate smallbitvec;
 extern crate smallvec;
+#[cfg(feature = "gecko")]
+extern crate static_prefs;
 #[cfg(feature = "servo")]
 extern crate string_cache;
 #[macro_use]
diff --git a/components/style/media_queries/media_feature_expression.rs b/components/style/media_queries/media_feature_expression.rs
index 310cbd2b8bbc..98c7d59c7e14 100644
--- a/components/style/media_queries/media_feature_expression.rs
+++ b/components/style/media_queries/media_feature_expression.rs
@@ -11,8 +11,6 @@ use super::Device;
 use crate::context::QuirksMode;
 #[cfg(feature = "gecko")]
 use crate::gecko::media_features::MEDIA_FEATURES;
-#[cfg(feature = "gecko")]
-use crate::gecko_bindings::structs;
 use crate::parser::{Parse, ParserContext};
 #[cfg(feature = "servo")]
 use crate::servo::media_queries::MEDIA_FEATURES;
@@ -301,9 +299,7 @@ impl MediaFeatureExpression {
                     if starts_with_ignore_ascii_case(feature_name, "-webkit-") {
                         feature_name = &feature_name[8..];
                         requirements.insert(ParsingRequirements::WEBKIT_PREFIX);
-                        if unsafe {
-                            structs::StaticPrefs::sVarCache_layout_css_prefixes_device_pixel_ratio_webkit
-                        } {
+                        if static_prefs::pref!("layout.css.prefixes.device-pixel-ratio-webkit") {
                             requirements.insert(
                                 ParsingRequirements::WEBKIT_DEVICE_PIXEL_RATIO_PREF_ENABLED,
                             );
diff --git a/components/style/properties/cascade.rs b/components/style/properties/cascade.rs
index c3ce242eadd2..da95840a08ac 100644
--- a/components/style/properties/cascade.rs
+++ b/components/style/properties/cascade.rs
@@ -673,7 +673,7 @@ impl<'a, 'b: 'a> Cascade<'a, 'b> {
     #[inline]
     #[cfg(feature = "gecko")]
     fn recompute_default_font_family_type_if_needed(&mut self) {
-        use crate::gecko_bindings::{bindings, structs};
+        use crate::gecko_bindings::bindings;
         use crate::values::computed::font::GenericFontFamily;
 
         if !self.seen.contains(LonghandId::XLang) &&
@@ -681,7 +681,7 @@ impl<'a, 'b: 'a> Cascade<'a, 'b> {
             return;
         }
 
-        let use_document_fonts = unsafe { structs::StaticPrefs::sVarCache_browser_display_use_document_fonts != 0 };
+        let use_document_fonts = static_prefs::pref!("browser.display.use_document_fonts") != 0;
         let builder = &mut self.context.builder;
         let (default_font_type, prioritize_user_fonts) = {
             let font = builder.get_font().gecko();
diff --git a/components/style/properties/data.py b/components/style/properties/data.py
index 46cb724e11df..d1e78e6648c2 100644
--- a/components/style/properties/data.py
+++ b/components/style/properties/data.py
@@ -652,9 +652,6 @@ def _remove_common_first_line_and_first_letter_properties(props, engine):
         props.remove("text-emphasis-position")
         props.remove("text-emphasis-style")
         props.remove("text-emphasis-color")
-        props.remove("text-decoration-skip-ink")
-        props.remove("text-decoration-thickness")
-        props.remove("text-underline-offset")
 
     props.remove("overflow-wrap")
     props.remove("text-align")
diff --git a/components/style/properties/gecko.mako.rs b/components/style/properties/gecko.mako.rs
index f00e5aafced2..1f3e862df495 100644
--- a/components/style/properties/gecko.mako.rs
+++ b/components/style/properties/gecko.mako.rs
@@ -973,11 +973,10 @@ fn static_assert() {
 
 <% skip_position_longhands = " ".join(x.ident for x in SIDES) %>
 <%self:impl_trait style_struct_name="Position"
-                  skip_longhands="${skip_position_longhands} order
+                  skip_longhands="${skip_position_longhands}
                                   align-content justify-content align-self
                                   justify-self align-items justify-items
-                                  grid-auto-flow grid-template-rows
-                                  grid-template-columns">
+                                  grid-auto-flow">
     % for side in SIDES:
     <% impl_split_style_coord(side.ident, "mOffset", side.index) %>
     % endfor
@@ -1015,226 +1014,6 @@ fn static_assert() {
         }
     }
 
-    pub fn set_order(&mut self, v: longhands::order::computed_value::T) {
-        self.gecko.mOrder = v;
-    }
-
-    pub fn clone_order(&self) -> longhands::order::computed_value::T {
-        self.gecko.mOrder
-    }
-
-    ${impl_simple_copy('order', 'mOrder')}
-
-    % for kind in ["rows", "columns"]:
-    pub fn set_grid_template_${kind}(&mut self, v: longhands::grid_template_${kind}::computed_value::T) {
-        <% self_grid = "self.gecko.mGridTemplate%s" % kind.title() %>
-        use crate::gecko_bindings::structs::nsTArray;
-        use std::usize;
-        use crate::values::CustomIdent;
-        use crate::values::generics::grid::TrackListType::Auto;
-        use crate::values::generics::grid::{GridTemplateComponent, RepeatCount, TrackListValue, MAX_GRID_LINE};
-
-        #[inline]
-        fn set_line_names(servo_names: &[CustomIdent], gecko_names: &mut nsTArray<structs::RefPtr<structs::nsAtom>>) {
-            unsafe {
-                bindings::Gecko_ResizeAtomArray(gecko_names, servo_names.len() as u32);
-            }
-
-            for (servo_name, gecko_name) in servo_names.iter().zip(gecko_names.iter_mut()) {
-                gecko_name.set_move(unsafe {
-                    RefPtr::from_addrefed(servo_name.0.clone().into_addrefed())
-                });
-            }
-        }
-
-        let max_lines = MAX_GRID_LINE as usize - 1; // for accounting the final <line-names>
-
-        let result = match v {
-            GridTemplateComponent::None => ptr::null_mut(),
-            GridTemplateComponent::TrackList(track) => {
-                let mut num_values = track.values.len();
-                if let Auto(_) = track.list_type {
-                    num_values += 1;
-                }
-
-                num_values = cmp::min(num_values, max_lines);
-                let value = unsafe {
-                    bindings::Gecko_CreateStyleGridTemplate(num_values as u32,
-                                                            (num_values + 1) as u32).as_mut().unwrap()
-                };
-
-                let mut auto_idx = usize::MAX;
-                let mut auto_track_size = None;
-                if let Auto(idx) = track.list_type {
-                    auto_idx = idx as usize;
-                    let auto_repeat = track.auto_repeat.as_ref().expect("expected <auto-track-repeat> value");
-
-                    if auto_repeat.count == RepeatCount::AutoFill {
-                        value.set_mIsAutoFill(true);
-                    }
-
-                    value.mRepeatAutoIndex = idx as i16;
-                    // NOTE: Gecko supports only one set of values in <auto-repeat>
-                    // i.e., it can only take repeat(auto-fill, [a] 10px [b]), and no more.
-                    set_line_names(&auto_repeat.line_names[0], &mut value.mRepeatAutoLineNameListBefore);
-                    set_line_names(&auto_repeat.line_names[1], &mut value.mRepeatAutoLineNameListAfter);
-                    auto_track_size = Some(auto_repeat.track_sizes.get(0).unwrap().clone());
-                } else {
-                    unsafe {
-                        bindings::Gecko_ResizeAtomArray(
-                            &mut value.mRepeatAutoLineNameListBefore, 0);
-                        bindings::Gecko_ResizeAtomArray(
-                            &mut value.mRepeatAutoLineNameListAfter, 0);
-                    }
-                }
-
-                let mut line_names = track.line_names.into_iter();
-                let mut values_iter = track.values.into_iter();
-                {
-                    for (i, track_size) in value.mTrackSizingFunctions.iter_mut().enumerate().take(max_lines) {
-                        let name_list = line_names.next().expect("expected line-names");
-                        set_line_names(&name_list, &mut value.mLineNameLists[i]);
-                        *track_size = if i == auto_idx {
-                            auto_track_size.take().expect("expected <track-size> for <auto-track-repeat>")
-                        } else {
-                            match values_iter.next().expect("expected <track-size> value") {
-                                TrackListValue::TrackSize(size) => size,
-                                // FIXME(emilio): This shouldn't be
-                                // representable in the first place.
-                                TrackListValue::TrackRepeat(..) => {
-                                    unreachable!("Shouldn't have track-repeats in computed track lists")
-                                }
-                            }
-                        };
-                    }
-                }
-
-                let final_names = line_names.next().unwrap();
-                set_line_names(&final_names, value.mLineNameLists.last_mut().unwrap());
-
-                value
-            },
-            GridTemplateComponent::Subgrid(list) => {
-                let names_length = match list.fill_idx {
-                    Some(_) => list.names.len() - 1,
-                    None => list.names.len(),
-                };
-                let num_values = cmp::min(names_length, max_lines + 1);
-                let value = unsafe {
-                    bindings::Gecko_CreateStyleGridTemplate(0, num_values as u32).as_mut().unwrap()
-                };
-                value.set_mIsSubgrid(true);
-
-                let mut names = list.names.into_vec();
-                if let Some(idx) = list.fill_idx {
-                    value.set_mIsAutoFill(true);
-                    value.mRepeatAutoIndex = idx as i16;
-                    set_line_names(&names.swap_remove(idx as usize),
-                                   &mut value.mRepeatAutoLineNameListBefore);
-                }
-
-                for (servo_names, gecko_names) in names.iter().zip(value.mLineNameLists.iter_mut()) {
-                    set_line_names(servo_names, gecko_names);
-                }
-
-                value
-            },
-        };
-
-        unsafe { bindings::Gecko_SetStyleGridTemplate(&mut ${self_grid}, result); }
-    }
-
-    pub fn copy_grid_template_${kind}_from(&mut self, other: &Self) {
-        unsafe {
-            bindings::Gecko_CopyStyleGridTemplateValues(&mut ${self_grid},
-                                                        other.gecko.mGridTemplate${kind.title()}.mPtr);
-        }
-    }
-
-    pub fn reset_grid_template_${kind}(&mut self, other: &Self) {
-        self.copy_grid_template_${kind}_from(other)
-    }
-
-    pub fn clone_grid_template_${kind}(&self) -> longhands::grid_template_${kind}::computed_value::T {
-        <% self_grid = "self.gecko.mGridTemplate%s" % kind.title() %>
-        use crate::gecko_bindings::structs::nsTArray;
-        use crate::values::CustomIdent;
-        use crate::values::generics::grid::{GridTemplateComponent, LineNameList, RepeatCount};
-        use crate::values::generics::grid::{TrackList, TrackListType, TrackListValue, TrackRepeat};
-
-        let value = match unsafe { ${self_grid}.mPtr.as_ref() } {
-            None => return GridTemplateComponent::None,
-            Some(value) => value,
-        };
-
-        #[inline]
-        fn to_boxed_customident_slice(gecko_names: &nsTArray<structs::RefPtr<structs::nsAtom>>) -> Box<[CustomIdent]> {
-            let idents: Vec<CustomIdent> = gecko_names.iter().map(|gecko_name| {
-                CustomIdent(unsafe { Atom::from_raw(gecko_name.mRawPtr) })
-            }).collect();
-            idents.into_boxed_slice()
-        }
-
-        #[inline]
-        fn to_line_names_vec(
-            gecko_line_names: &nsTArray<nsTArray<structs::RefPtr<structs::nsAtom>>>,
-        ) -> Vec<Box<[CustomIdent]>> {
-            gecko_line_names.iter().map(|gecko_names| {
-                to_boxed_customident_slice(gecko_names)
-            }).collect()
-        }
-
-        let repeat_auto_index = value.mRepeatAutoIndex as usize;
-        if value.mIsSubgrid() {
-            let mut names_vec = to_line_names_vec(&value.mLineNameLists);
-            let fill_idx = if value.mIsAutoFill() {
-                names_vec.insert(
-                    repeat_auto_index,
-                    to_boxed_customident_slice(&value.mRepeatAutoLineNameListBefore));
-                Some(repeat_auto_index as u32)
-            } else {
-                None
-            };
-            let names = names_vec.into_boxed_slice();
-
-            GridTemplateComponent::Subgrid(LineNameList{names, fill_idx})
-        } else {
-            let mut auto_repeat = None;
-            let mut list_type = TrackListType::Normal;
-            let line_names = to_line_names_vec(&value.mLineNameLists).into_boxed_slice();
-            let mut values = Vec::with_capacity(value.mTrackSizingFunctions.len());
-            for (i, track_size) in value.mTrackSizingFunctions.iter().enumerate() {
-                if i == repeat_auto_index {
-                    list_type = TrackListType::Auto(repeat_auto_index as u16);
-
-                    let count = if value.mIsAutoFill() {
-                        RepeatCount::AutoFill
-                    } else {
-                        RepeatCount::AutoFit
-                    };
-
-                    let line_names = {
-                        let mut vec: Vec<Box<[CustomIdent]>> = Vec::with_capacity(2);
-                        vec.push(to_boxed_customident_slice(
-                            &value.mRepeatAutoLineNameListBefore));
-                        vec.push(to_boxed_customident_slice(
-                            &value.mRepeatAutoLineNameListAfter));
-                        vec.into_boxed_slice()
-                    };
-
-                    let track_sizes = vec!(track_size.clone());
-
-                    auto_repeat = Some(TrackRepeat{count, line_names, track_sizes});
-                } else {
-                    values.push(TrackListValue::TrackSize(track_size.clone()));
-                }
-            }
-
-            GridTemplateComponent::TrackList(TrackList{list_type, values, line_names, auto_repeat})
-        }
-    }
-    % endfor
-
     ${impl_simple_type_with_conversion("grid_auto_flow")}
 </%self:impl_trait>
 
@@ -2799,97 +2578,15 @@ fn static_assert() {
 
 
 <%self:impl_trait style_struct_name="InheritedText"
-                  skip_longhands="text-align text-emphasis-style
-                                  -webkit-text-stroke-width text-emphasis-position">
+                  skip_longhands="text-align -webkit-text-stroke-width text-emphasis-position">
 
     <% text_align_keyword = Keyword("text-align",
                                     "start end left right center justify -moz-center -moz-left -moz-right char",
                                     gecko_strip_moz_prefix=False) %>
     ${impl_keyword('text_align', 'mTextAlign', text_align_keyword)}
 
-    fn clear_text_emphasis_style_if_string(&mut self) {
-        if self.gecko.mTextEmphasisStyle == structs::NS_STYLE_TEXT_EMPHASIS_STYLE_STRING as u8 {
-            self.gecko.mTextEmphasisStyleString.truncate();
-            self.gecko.mTextEmphasisStyle = structs::NS_STYLE_TEXT_EMPHASIS_STYLE_NONE as u8;
-        }
-    }
-
     ${impl_simple_type_with_conversion("text_emphasis_position")}
 
-    pub fn set_text_emphasis_style(&mut self, v: values::computed::TextEmphasisStyle) {
-        use crate::values::computed::TextEmphasisStyle;
-        use crate::values::specified::text::{TextEmphasisFillMode, TextEmphasisShapeKeyword};
-
-        self.clear_text_emphasis_style_if_string();
-        let (te, s) = match v {
-            TextEmphasisStyle::None => (structs::NS_STYLE_TEXT_EMPHASIS_STYLE_NONE, ""),
-            TextEmphasisStyle::Keyword(ref keyword) => {
-                let fill = match keyword.fill {
-                    TextEmphasisFillMode::Filled => structs::NS_STYLE_TEXT_EMPHASIS_STYLE_FILLED,
-                    TextEmphasisFillMode::Open => structs::NS_STYLE_TEXT_EMPHASIS_STYLE_OPEN,
-                };
-                let shape = match keyword.shape {
-                    TextEmphasisShapeKeyword::Dot => structs::NS_STYLE_TEXT_EMPHASIS_STYLE_DOT,
-                    TextEmphasisShapeKeyword::Circle => structs::NS_STYLE_TEXT_EMPHASIS_STYLE_CIRCLE,
-                    TextEmphasisShapeKeyword::DoubleCircle => structs::NS_STYLE_TEXT_EMPHASIS_STYLE_DOUBLE_CIRCLE,
-                    TextEmphasisShapeKeyword::Triangle => structs::NS_STYLE_TEXT_EMPHASIS_STYLE_TRIANGLE,
-                    TextEmphasisShapeKeyword::Sesame => structs::NS_STYLE_TEXT_EMPHASIS_STYLE_SESAME,
-                };
-
-                (shape | fill, keyword.shape.char(keyword.fill))
-            },
-            TextEmphasisStyle::String(ref s) => {
-                (structs::NS_STYLE_TEXT_EMPHASIS_STYLE_STRING, &**s)
-            },
-        };
-        self.gecko.mTextEmphasisStyleString.assign_str(s);
-        self.gecko.mTextEmphasisStyle = te as u8;
-    }
-
-    pub fn copy_text_emphasis_style_from(&mut self, other: &Self) {
-        self.clear_text_emphasis_style_if_string();
-        if other.gecko.mTextEmphasisStyle == structs::NS_STYLE_TEXT_EMPHASIS_STYLE_STRING as u8 {
-            self.gecko.mTextEmphasisStyleString
-                      .assign(&*other.gecko.mTextEmphasisStyleString)
-        }
-        self.gecko.mTextEmphasisStyle = other.gecko.mTextEmphasisStyle;
-    }
-
-    pub fn reset_text_emphasis_style(&mut self, other: &Self) {
-        self.copy_text_emphasis_style_from(other)
-    }
-
-    pub fn clone_text_emphasis_style(&self) -> values::computed::TextEmphasisStyle {
-        use crate::values::computed::TextEmphasisStyle;
-        use crate::values::computed::text::TextEmphasisKeywordValue;
-        use crate::values::specified::text::{TextEmphasisFillMode, TextEmphasisShapeKeyword};
-
-        if self.gecko.mTextEmphasisStyle == structs::NS_STYLE_TEXT_EMPHASIS_STYLE_NONE as u8 {
-            return TextEmphasisStyle::None;
-        }
-
-        if self.gecko.mTextEmphasisStyle == structs::NS_STYLE_TEXT_EMPHASIS_STYLE_STRING as u8 {
-            return TextEmphasisStyle::String(self.gecko.mTextEmphasisStyleString.to_string());
-        }
-
-        let fill =
-            self.gecko.mTextEmphasisStyle & structs::NS_STYLE_TEXT_EMPHASIS_STYLE_OPEN as u8 == 0;
-
-        let fill = if fill { TextEmphasisFillMode::Filled } else { TextEmphasisFillMode::Open };
-
-        let shape =
-            match self.gecko.mTextEmphasisStyle as u32 & !structs::NS_STYLE_TEXT_EMPHASIS_STYLE_OPEN {
-                structs::NS_STYLE_TEXT_EMPHASIS_STYLE_DOT => TextEmphasisShapeKeyword::Dot,
-                structs::NS_STYLE_TEXT_EMPHASIS_STYLE_CIRCLE => TextEmphasisShapeKeyword::Circle,
-                structs::NS_STYLE_TEXT_EMPHASIS_STYLE_DOUBLE_CIRCLE => TextEmphasisShapeKeyword::DoubleCircle,
-                structs::NS_STYLE_TEXT_EMPHASIS_STYLE_TRIANGLE => TextEmphasisShapeKeyword::Triangle,
-                structs::NS_STYLE_TEXT_EMPHASIS_STYLE_SESAME => TextEmphasisShapeKeyword::Sesame,
-                _ => panic!("Unexpected value in style struct for text-emphasis-style property")
-            };
-
-        TextEmphasisStyle::Keyword(TextEmphasisKeywordValue { fill, shape })
-    }
-
     ${impl_non_negative_length('_webkit_text_stroke_width',
                                'mWebkitTextStrokeWidth')}
 
diff --git a/components/style/properties/longhands/border.mako.rs b/components/style/properties/longhands/border.mako.rs
index 6ac01034bedb..4098a94208fd 100644
--- a/components/style/properties/longhands/border.mako.rs
+++ b/components/style/properties/longhands/border.mako.rs
@@ -58,7 +58,6 @@
         animation_value_type="NonNegativeLength",
         logical=is_logical,
         logical_group="border-width",
-        flags="GETCS_NEEDS_LAYOUT_FLUSH",
         allow_quirks="No" if is_logical else "Yes",
         servo_restyle_damage="reflow rebuild_and_reflow_inline"
     )}
diff --git a/components/style/properties/longhands/box.mako.rs b/components/style/properties/longhands/box.mako.rs
index 40075a650843..4dcc43aec239 100644
--- a/components/style/properties/longhands/box.mako.rs
+++ b/components/style/properties/longhands/box.mako.rs
@@ -339,8 +339,7 @@ ${helpers.predefined_type(
     servo_2020_pref="layout.2020.unimplemented",
     extra_prefixes=transform_extra_prefixes,
     animation_value_type="ComputedValue",
-    flags="CREATES_STACKING_CONTEXT FIXPOS_CB \
-           GETCS_NEEDS_LAYOUT_FLUSH CAN_ANIMATE_ON_COMPOSITOR",
+    flags="CREATES_STACKING_CONTEXT FIXPOS_CB CAN_ANIMATE_ON_COMPOSITOR",
     spec="https://drafts.csswg.org/css-transforms/#propdef-transform",
     servo_restyle_damage="reflow_out_of_flow",
 )}
@@ -421,6 +420,19 @@ ${helpers.predefined_type(
     servo_restyle_damage="reflow_out_of_flow"
 )}
 
+// Motion Path Module Level 1
+${helpers.predefined_type(
+    "offset-anchor",
+    "PositionOrAuto",
+    "computed::PositionOrAuto::auto()",
+    engines="gecko",
+    animation_value_type="ComputedValue",
+    gecko_pref="layout.css.motion-path.enabled",
+    spec="https://drafts.fxtf.org/motion-1/#offset-anchor-property",
+    servo_restyle_damage="reflow_out_of_flow",
+    boxed=True
+)}
+
 // CSSOM View Module
 // https://www.w3.org/TR/cssom-view-1/
 ${helpers.single_keyword(
@@ -539,7 +551,6 @@ ${helpers.predefined_type(
     boxed=True,
     extra_prefixes=transform_extra_prefixes,
     spec="https://drafts.csswg.org/css-transforms-2/#perspective-origin-property",
-    flags="GETCS_NEEDS_LAYOUT_FLUSH",
     animation_value_type="ComputedValue",
     servo_restyle_damage="reflow_out_of_flow"
 )}
@@ -587,7 +598,6 @@ ${helpers.predefined_type(
     extra_prefixes=transform_extra_prefixes,
     gecko_ffi_name="mTransformOrigin",
     boxed=True,
-    flags="GETCS_NEEDS_LAYOUT_FLUSH",
     spec="https://drafts.csswg.org/css-transforms/#transform-origin-property",
     servo_restyle_damage="reflow_out_of_flow",
 )}
diff --git a/components/style/properties/longhands/inherited_text.mako.rs b/components/style/properties/longhands/inherited_text.mako.rs
index f45369c27c77..18f5c466d1a0 100644
--- a/components/style/properties/longhands/inherited_text.mako.rs
+++ b/components/style/properties/longhands/inherited_text.mako.rs
@@ -23,7 +23,6 @@ ${helpers.predefined_type(
     engines="gecko servo-2013 servo-2020",
     servo_2020_pref="layout.2020.unimplemented",
     animation_value_type="LineHeight",
-    flags="GETCS_NEEDS_LAYOUT_FLUSH",
     spec="https://drafts.csswg.org/css2/visudet.html#propdef-line-height",
     servo_restyle_damage="reflow"
 )}
@@ -250,7 +249,6 @@ ${helpers.predefined_type(
     None,
     engines="gecko",
     initial_specified_value="SpecifiedValue::None",
-    boxed=True,
     animation_value_type="discrete",
     spec="https://drafts.csswg.org/css-text-decor/#propdef-text-emphasis-style",
 )}
@@ -384,8 +382,8 @@ ${helpers.single_keyword(
 // text underline offset
 ${helpers.predefined_type(
     "text-underline-offset",
-    "LengthOrAuto",
-    "computed::LengthOrAuto::auto()",
+    "TextDecorationLength",
+    "generics::text::GenericTextDecorationLength::Auto",
     engines="gecko",
     animation_value_type="ComputedValue",
     gecko_pref="layout.css.text-underline-offset.enabled",
diff --git a/components/style/properties/longhands/margin.mako.rs b/components/style/properties/longhands/margin.mako.rs
index 820634be9952..9ec1e97504c5 100644
--- a/components/style/properties/longhands/margin.mako.rs
+++ b/components/style/properties/longhands/margin.mako.rs
@@ -24,7 +24,6 @@
         logical=side[1],
         logical_group="margin",
         spec=spec,
-        flags="GETCS_NEEDS_LAYOUT_FLUSH",
         allowed_in_page_rule=True,
         servo_restyle_damage="reflow"
     )}
diff --git a/components/style/properties/longhands/padding.mako.rs b/components/style/properties/longhands/padding.mako.rs
index faa3fb2867c5..a91f1238979b 100644
--- a/components/style/properties/longhands/padding.mako.rs
+++ b/components/style/properties/longhands/padding.mako.rs
@@ -23,7 +23,6 @@
         logical=side[1],
         logical_group="padding",
         spec=spec,
-        flags="GETCS_NEEDS_LAYOUT_FLUSH",
         allow_quirks="No" if side[1] else "Yes",
         servo_restyle_damage="reflow rebuild_and_reflow_inline"
     )}
diff --git a/components/style/properties/longhands/position.mako.rs b/components/style/properties/longhands/position.mako.rs
index 9e67dfb2d806..a63f7637db4c 100644
--- a/components/style/properties/longhands/position.mako.rs
+++ b/components/style/properties/longhands/position.mako.rs
@@ -17,7 +17,6 @@
         engines="gecko servo-2013 servo-2020",
         servo_2020_pref="layout.2020.unimplemented",
         spec="https://www.w3.org/TR/CSS2/visuren.html#propdef-%s" % side,
-        flags="GETCS_NEEDS_LAYOUT_FLUSH",
         animation_value_type="ComputedValue",
         allow_quirks="Yes",
         servo_restyle_damage="reflow_out_of_flow",
@@ -33,7 +32,6 @@
         engines="gecko servo-2013 servo-2020",
         servo_2020_pref="layout.2020.unimplemented",
         spec="https://drafts.csswg.org/css-logical-props/#propdef-inset-%s" % side,
-        flags="GETCS_NEEDS_LAYOUT_FLUSH",
         alias="offset-%s:layout.css.offset-logical-properties.enabled" % side,
         animation_value_type="ComputedValue",
         logical=True,
@@ -285,7 +283,6 @@ ${helpers.predefined_type(
         allow_quirks="No" if logical else "Yes",
         spec=spec % size,
         animation_value_type="Size",
-        flags="GETCS_NEEDS_LAYOUT_FLUSH",
         servo_restyle_damage="reflow",
     )}
     // min-width, min-height, min-block-size, min-inline-size
@@ -360,16 +357,13 @@ ${helpers.predefined_type(
         )}
     % endfor
 
-    // NOTE: According to the spec, this should handle multiple values of `<track-size>`,
-    // but gecko supports only a single value
     ${helpers.predefined_type(
         "grid-auto-%ss" % kind,
-        "TrackSize",
+        "ImplicitGridTracks",
         "Default::default()",
         engines="gecko",
         animation_value_type="discrete",
         spec="https://drafts.csswg.org/css-grid/#propdef-grid-auto-%ss" % kind,
-        boxed=True,
     )}
 
     ${helpers.predefined_type(
@@ -378,8 +372,6 @@ ${helpers.predefined_type(
         "specified::GenericGridTemplateComponent::None",
         engines="gecko",
         spec="https://drafts.csswg.org/css-grid/#propdef-grid-template-%ss" % kind,
-        boxed=True,
-        flags="GETCS_NEEDS_LAYOUT_FLUSH",
         animation_value_type="ComputedValue",
     )}
 
diff --git a/components/style/properties/longhands/text.mako.rs b/components/style/properties/longhands/text.mako.rs
index a592e2f12908..b77e17dd6b75 100644
--- a/components/style/properties/longhands/text.mako.rs
+++ b/components/style/properties/longhands/text.mako.rs
@@ -71,9 +71,10 @@ ${helpers.predefined_type(
 
 ${helpers.predefined_type(
    "text-decoration-thickness",
-   "LengthOrAuto",
-   "computed::LengthOrAuto::auto()",
+   "TextDecorationLength",
+   "generics::text::GenericTextDecorationLength::Auto",
    engines="gecko",
+   initial_specified_value="generics::text::GenericTextDecorationLength::Auto",
    animation_value_type="ComputedValue",
    gecko_pref="layout.css.text-decoration-thickness.enabled",
    spec="https://drafts.csswg.org/css-text-decor-4/#text-decoration-width-property"
diff --git a/components/style/properties/longhands/ui.mako.rs b/components/style/properties/longhands/ui.mako.rs
index d59be17a27a9..647028559677 100644
--- a/components/style/properties/longhands/ui.mako.rs
+++ b/components/style/properties/longhands/ui.mako.rs
@@ -80,7 +80,6 @@ ${helpers.predefined_type(
     "Transform",
     "generics::transform::Transform::none()",
     engines="gecko",
-    flags="GETCS_NEEDS_LAYOUT_FLUSH",
     animation_value_type="ComputedValue",
     spec="None (Nonstandard internal property)",
     enabled_in="chrome",
@@ -94,7 +93,6 @@ ${helpers.predefined_type(
     animation_value_type="ComputedValue",
     gecko_ffi_name="mWindowTransformOrigin",
     boxed=True,
-    flags="GETCS_NEEDS_LAYOUT_FLUSH",
     spec="None (Nonstandard internal property)",
     enabled_in="chrome",
 )}
diff --git a/components/style/properties/properties.mako.rs b/components/style/properties/properties.mako.rs
index c16de38f2042..72ae381f5d9f 100644
--- a/components/style/properties/properties.mako.rs
+++ b/components/style/properties/properties.mako.rs
@@ -981,13 +981,10 @@ bitflags! {
         const APPLIES_TO_CUE = 1 << 6;
         /// This longhand property applies to ::marker.
         const APPLIES_TO_MARKER = 1 << 7;
-        /// This property's getComputedStyle implementation requires layout
-        /// to be flushed.
-        const GETCS_NEEDS_LAYOUT_FLUSH = 1 << 8;
         /// This property is a legacy shorthand.
         ///
         /// https://drafts.csswg.org/css-cascade/#legacy-shorthand
-        const IS_LEGACY_SHORTHAND = 1 << 9;
+        const IS_LEGACY_SHORTHAND = 1 << 8;
 
         /* The following flags are currently not used in Rust code, they
          * only need to be listed in corresponding properties so that
diff --git a/components/style/properties/shorthands/position.mako.rs b/components/style/properties/shorthands/position.mako.rs
index 8e61f0f6ecdd..81a54dbfa572 100644
--- a/components/style/properties/shorthands/position.mako.rs
+++ b/components/style/properties/shorthands/position.mako.rs
@@ -268,7 +268,7 @@
 >
     use crate::parser::Parse;
     use servo_arc::Arc;
-    use crate::values::generics::grid::{TrackSize, TrackList, TrackListType};
+    use crate::values::generics::grid::{TrackSize, TrackList};
     use crate::values::generics::grid::{TrackListValue, concat_serialize_idents};
     use crate::values::specified::{GridTemplateComponent, GenericGridTemplateComponent};
     use crate::values::specified::grid::parse_line_names;
@@ -300,26 +300,28 @@
             }
         % endfor
 
-        let first_line_names = input.try(parse_line_names).unwrap_or(vec![].into_boxed_slice());
+        let first_line_names = input.try(parse_line_names).unwrap_or_default();
         if let Ok(mut string) = input.try(|i| i.expect_string().map(|s| s.as_ref().to_owned().into())) {
             let mut strings = vec![];
             let mut values = vec![];
             let mut line_names = vec![];
-            let mut names = first_line_names.into_vec();
+            let mut names = first_line_names;
             loop {
-                line_names.push(names.into_boxed_slice());
+                line_names.push(names);
                 strings.push(string);
                 let size = input.try(|i| TrackSize::parse(context, i)).unwrap_or_default();
                 values.push(TrackListValue::TrackSize(size));
-                names = input.try(parse_line_names).unwrap_or(vec![].into_boxed_slice()).into_vec();
+                names = input.try(parse_line_names).unwrap_or_default();
                 if let Ok(v) = input.try(parse_line_names) {
-                    names.extend(v.into_vec());
+                    let mut names_vec = names.into_vec();
+                    names_vec.extend(v.into_iter());
+                    names = names_vec.into();
                 }
 
                 string = match input.try(|i| i.expect_string().map(|s| s.as_ref().to_owned().into())) {
                     Ok(s) => s,
                     _ => {      // only the named area determines whether we should bail out
-                        line_names.push(names.into_boxed_slice());
+                        line_names.push(names.into());
                         break
                     },
                 };
@@ -327,22 +329,21 @@
 
             if line_names.len() == values.len() {
                 // should be one longer than track sizes
-                line_names.push(vec![].into_boxed_slice());
+                line_names.push(Default::default());
             }
 
             let template_areas = TemplateAreas::from_vec(strings)
                 .map_err(|()| input.new_custom_error(StyleParseErrorKind::UnspecifiedError))?;
             let template_rows = TrackList {
-                list_type: TrackListType::Normal,
-                values,
-                line_names: line_names.into_boxed_slice(),
-                auto_repeat: None,
+                values: values.into(),
+                line_names: line_names.into(),
+                auto_repeat_index: std::usize::MAX,
             };
 
             let template_cols = if input.try(|i| i.expect_delim('/')).is_ok() {
                 let value = GridTemplateComponent::parse_without_none(context, input)?;
                 if let GenericGridTemplateComponent::TrackList(ref list) = value {
-                    if list.list_type != TrackListType::Explicit {
+                    if !list.is_explicit() {
                         return Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError))
                     }
                 }
@@ -352,8 +353,11 @@
                 GenericGridTemplateComponent::None
             };
 
-            Ok((GenericGridTemplateComponent::TrackList(template_rows),
-                template_cols, GridTemplateAreas::Areas(TemplateAreasArc(Arc::new(template_areas)))))
+            Ok((
+                GenericGridTemplateComponent::TrackList(Box::new(template_rows)),
+                template_cols,
+                GridTemplateAreas::Areas(TemplateAreasArc(Arc::new(template_areas)))
+            ))
         } else {
             let mut template_rows = GridTemplateComponent::parse(context, input)?;
             if let GenericGridTemplateComponent::TrackList(ref mut list) = template_rows {
@@ -407,13 +411,10 @@
 
                 let track_list = match *template_rows {
                     GenericGridTemplateComponent::TrackList(ref list) => {
-                        // We should fail if there is a `repeat` function. `grid` and
-                        // `grid-template` shorthands doesn't accept that. Only longhand accepts.
-                        if list.auto_repeat.is_some() ||
-                           list.values.iter().any(|v| match *v {
-                               TrackListValue::TrackRepeat(_) => true,
-                               _ => false,
-                           }) {
+                        // We should fail if there is a `repeat` function.
+                        // `grid` and `grid-template` shorthands doesn't accept
+                        // that. Only longhand accepts.
+                        if !list.is_explicit() {
                             return Ok(());
                         }
                         list
@@ -429,11 +430,7 @@
                     // We should fail if there is a `repeat` function. `grid` and
                     // `grid-template` shorthands doesn't accept that. Only longhand accepts that.
                     GenericGridTemplateComponent::TrackList(ref list) => {
-                        if list.auto_repeat.is_some() ||
-                           list.values.iter().any(|v| match *v {
-                               TrackListValue::TrackRepeat(_) => true,
-                               _ => false,
-                           }) {
+                        if !list.is_explicit() {
                             return Ok(());
                         }
                     },
@@ -498,8 +495,8 @@
 >
     use crate::parser::Parse;
     use crate::properties::longhands::{grid_auto_columns, grid_auto_rows, grid_auto_flow};
-    use crate::values::generics::grid::{GridTemplateComponent, TrackListType};
-    use crate::values::specified::{GenericGridTemplateComponent, TrackSize};
+    use crate::values::generics::grid::GridTemplateComponent;
+    use crate::values::specified::{GenericGridTemplateComponent, ImplicitGridTracks};
     use crate::values::specified::position::{AutoFlow, GridAutoFlow, GridTemplateAreas};
 
     pub fn parse_value<'i, 't>(
@@ -509,8 +506,8 @@
         let mut temp_rows = GridTemplateComponent::None;
         let mut temp_cols = GridTemplateComponent::None;
         let mut temp_areas = GridTemplateAreas::None;
-        let mut auto_rows = TrackSize::default();
-        let mut auto_cols = TrackSize::default();
+        let mut auto_rows = ImplicitGridTracks::default();
+        let mut auto_cols = ImplicitGridTracks::default();
         let mut flow = grid_auto_flow::get_initial_value();
 
         fn parse_auto_flow<'i, 't>(
@@ -571,8 +568,8 @@
         /// Returns true if other sub properties except template-{rows,columns} are initial.
         fn is_grid_template(&self) -> bool {
             *self.grid_template_areas == GridTemplateAreas::None &&
-            *self.grid_auto_rows == TrackSize::default() &&
-            *self.grid_auto_columns == TrackSize::default() &&
+            self.grid_auto_rows.is_initial() &&
+            self.grid_auto_columns.is_initial() &&
             *self.grid_auto_flow == grid_auto_flow::get_initial_value()
         }
     }
@@ -590,14 +587,14 @@
 
             if self.grid_auto_flow.autoflow == AutoFlow::Column {
                 // It should fail to serialize if other branch of the if condition's values are set.
-                if *self.grid_auto_rows != TrackSize::default() ||
+                if !self.grid_auto_rows.is_initial() ||
                    *self.grid_template_columns != GridTemplateComponent::None {
                     return Ok(());
                 }
 
                 // It should fail to serialize if template-rows value is not Explicit.
                 if let GenericGridTemplateComponent::TrackList(ref list) = *self.grid_template_rows {
-                    if list.list_type != TrackListType::Explicit {
+                    if !list.is_explicit() {
                         return Ok(());
                     }
                 }
@@ -608,20 +605,20 @@
                     dest.write_str(" dense")?;
                 }
 
-                if !self.grid_auto_columns.is_default() {
+                if !self.grid_auto_columns.is_initial() {
                     dest.write_str(" ")?;
                     self.grid_auto_columns.to_css(dest)?;
                 }
             } else {
                 // It should fail to serialize if other branch of the if condition's values are set.
-                if *self.grid_auto_columns != TrackSize::default() ||
+                if !self.grid_auto_columns.is_initial() ||
                    *self.grid_template_rows != GridTemplateComponent::None {
                     return Ok(());
                 }
 
                 // It should fail to serialize if template-column value is not Explicit.
                 if let GenericGridTemplateComponent::TrackList(ref list) = *self.grid_template_columns {
-                    if list.list_type != TrackListType::Explicit {
+                    if !list.is_explicit() {
                         return Ok(());
                     }
                 }
@@ -631,7 +628,7 @@
                     dest.write_str(" dense")?;
                 }
 
-                if !self.grid_auto_rows.is_default() {
+                if !self.grid_auto_rows.is_initial() {
                     dest.write_str(" ")?;
                     self.grid_auto_rows.to_css(dest)?;
                 }
diff --git a/components/style/properties/shorthands/text.mako.rs b/components/style/properties/shorthands/text.mako.rs
index 905512b08df8..33b4a074892c 100644
--- a/components/style/properties/shorthands/text.mako.rs
+++ b/components/style/properties/shorthands/text.mako.rs
@@ -8,12 +8,13 @@
                     engines="gecko servo-2013"
                     flags="SHORTHAND_IN_GETCS"
                     sub_properties="text-decoration-line
-                    ${' text-decoration-style text-decoration-color' if engine == 'gecko' else ''}"
+                    ${' text-decoration-style text-decoration-color text-decoration-thickness' if engine == 'gecko' else ''}"
                     spec="https://drafts.csswg.org/css-text-decor/#propdef-text-decoration">
 
     % if engine == "gecko":
         use crate::values::specified;
-        use crate::properties::longhands::{text_decoration_style, text_decoration_color};
+        use crate::properties::longhands::{text_decoration_style, text_decoration_color, text_decoration_thickness};
+        use crate::properties::{PropertyId, LonghandId};
     % endif
     use crate::properties::longhands::text_decoration_line;
 
@@ -22,7 +23,10 @@
         input: &mut Parser<'i, 't>,
     ) -> Result<Longhands, ParseError<'i>> {
         % if engine == "gecko":
-            let (mut line, mut style, mut color, mut any) = (None, None, None, false);
+            let text_decoration_thickness_enabled =
+                PropertyId::Longhand(LonghandId::TextDecorationThickness).enabled_for_all_content();
+
+            let (mut line, mut style, mut color, mut thickness, mut any) = (None, None, None, None, false);
         % else:
             let (mut line, mut any) = (None, false);
         % endif
@@ -45,6 +49,9 @@
             % if engine == "gecko":
                 parse_component!(style, text_decoration_style);
                 parse_component!(color, text_decoration_color);
+                if text_decoration_thickness_enabled {
+                    parse_component!(thickness, text_decoration_thickness);
+                }
             % endif
 
             break;
@@ -60,6 +67,7 @@
             % if engine == "gecko":
                 text_decoration_style: unwrap_or_initial!(text_decoration_style, style),
                 text_decoration_color: unwrap_or_initial!(text_decoration_color, color),
+                text_decoration_thickness: unwrap_or_initial!(text_decoration_thickness, thickness),
             % endif
         })
     }
@@ -78,6 +86,13 @@
                     dest.write_str(" ")?;
                     self.text_decoration_color.to_css(dest)?;
                 }
+
+                if let Some(text_decoration_thickness) = self.text_decoration_thickness {
+                    if !text_decoration_thickness.is_auto() {
+                        dest.write_str(" ")?;
+                        self.text_decoration_thickness.to_css(dest)?;
+                    }
+                }
             % endif
 
             Ok(())
diff --git a/components/style/style_adjuster.rs b/components/style/style_adjuster.rs
index 38b908a16c63..041d2f76cafa 100644
--- a/components/style/style_adjuster.rs
+++ b/components/style/style_adjuster.rs
@@ -12,6 +12,7 @@ use crate::properties::longhands::float::computed_value::T as Float;
 use crate::properties::longhands::overflow_x::computed_value::T as Overflow;
 use crate::properties::longhands::position::computed_value::T as Position;
 use crate::properties::{self, ComputedValues, StyleBuilder};
+use crate::values::specified::box_::DisplayInside;
 use app_units::Au;
 
 /// A struct that implements all the adjustment methods.
@@ -175,7 +176,9 @@ impl<'a, 'b: 'a> StyleAdjuster<'a, 'b> {
     /// Apply the blockification rules based on the table in CSS 2.2 section 9.7.
     /// <https://drafts.csswg.org/css2/visuren.html#dis-pos-flo>
     /// A ::marker pseudo-element with 'list-style-position:outside' needs to
-    /// have its 'display' blockified.
+    /// have its 'display' blockified, unless the ::marker is for an inline
+    /// list-item (for which 'list-style-position:outside' behaves as 'inside').
+    /// https://drafts.csswg.org/css-lists-3/#list-style-position-property
     fn blockify_if_necessary<E>(&mut self, layout_parent_style: &ComputedValues, element: Option<E>)
     where
         E: TElement,
@@ -194,10 +197,8 @@ impl<'a, 'b: 'a> StyleAdjuster<'a, 'b> {
         let is_root = self.style.pseudo.is_none() && element.map_or(false, |e| e.is_root());
         blockify_if!(is_root);
         if !self.skip_item_display_fixup(element) {
-            blockify_if!(layout_parent_style
-                .get_box()
-                .clone_display()
-                .is_item_container());
+            let parent_display = layout_parent_style.get_box().clone_display();
+            blockify_if!(parent_display.is_item_container());
         }
 
         let is_item_or_root = blockify;
@@ -207,7 +208,8 @@ impl<'a, 'b: 'a> StyleAdjuster<'a, 'b> {
         blockify_if!(
             self.style.pseudo.map_or(false, |p| p.is_marker()) &&
                 self.style.get_parent_list().clone_list_style_position() ==
-                    ListStylePosition::Outside
+                    ListStylePosition::Outside &&
+                layout_parent_style.get_box().clone_display().inside() != DisplayInside::Inline
         );
 
         if !blockify {
diff --git a/components/style/stylesheets/document_rule.rs b/components/style/stylesheets/document_rule.rs
index 62e814ac48bd..942d60a7d178 100644
--- a/components/style/stylesheets/document_rule.rs
+++ b/components/style/stylesheets/document_rule.rs
@@ -253,20 +253,18 @@ impl DocumentCondition {
 
     #[cfg(feature = "gecko")]
     fn allowed_in(&self, context: &ParserContext) -> bool {
-        use crate::gecko_bindings::structs;
         use crate::stylesheets::Origin;
+        use static_prefs::pref;
 
         if context.stylesheet_origin != Origin::Author {
             return true;
         }
 
-        if unsafe { structs::StaticPrefs::sVarCache_layout_css_moz_document_content_enabled } {
+        if pref!("layout.css.moz-document.content.enabled") {
             return true;
         }
 
-        if !unsafe {
-            structs::StaticPrefs::sVarCache_layout_css_moz_document_url_prefix_hack_enabled
-        } {
+        if !pref!("layout.css.moz-document.url-prefix-hack.enabled") {
             return false;
         }
 
diff --git a/components/style/stylesheets/supports_rule.rs b/components/style/stylesheets/supports_rule.rs
index 4b709974c7dc..9ef3558bd1c2 100644
--- a/components/style/stylesheets/supports_rule.rs
+++ b/components/style/stylesheets/supports_rule.rs
@@ -323,9 +323,7 @@ impl RawSelector {
     pub fn eval(&self, context: &ParserContext, namespaces: &Namespaces) -> bool {
         #[cfg(feature = "gecko")]
         {
-            if unsafe {
-                !crate::gecko_bindings::structs::StaticPrefs::sVarCache_layout_css_supports_selector_enabled
-            } {
+            if !static_prefs::pref!("layout.css.supports-selector.enabled") {
                 return false;
             }
         }
diff --git a/components/style/values/animated/grid.rs b/components/style/values/animated/grid.rs
index d1f6be1a32b2..7b9417a08c6f 100644
--- a/components/style/values/animated/grid.rs
+++ b/components/style/values/animated/grid.rs
@@ -101,7 +101,7 @@ impl Animate for generics::TrackRepeat<LengthPercentage, Integer> {
         Ok(generics::TrackRepeat {
             count,
             line_names,
-            track_sizes,
+            track_sizes: track_sizes.into(),
         })
     }
 }
@@ -117,20 +117,19 @@ impl Animate for TrackList {
             return Err(());
         }
 
-        if self.list_type != other.list_type {
+        if self.is_explicit() != other.is_explicit() {
             return Err(());
         }
 
-        // For now, repeat(auto-fill/auto-fit, ...) is not animatable. TrackRepeat will
-        // return Err(()) if we use keywords. Therefore, we can early return here to avoid
-        // traversing |values| in <auto-track-list>. This may be updated in the future.
+        // For now, repeat(auto-fill/auto-fit, ...) is not animatable.
+        // TrackRepeat will return Err(()) if we use keywords. Therefore, we can
+        // early return here to avoid traversing |values| in <auto-track-list>.
+        // This may be updated in the future.
         // https://github.com/w3c/csswg-drafts/issues/3503
-        if let generics::TrackListType::Auto(_) = self.list_type {
+        if self.has_auto_repeat() || other.has_auto_repeat() {
             return Err(());
         }
 
-        let list_type = self.list_type;
-        let auto_repeat = self.auto_repeat.animate(&other.auto_repeat, procedure)?;
         let values = self
             .values
             .iter()
@@ -142,10 +141,9 @@ impl Animate for TrackList {
         let line_names = discrete(&self.line_names, &other.line_names, procedure)?;
 
         Ok(TrackList {
-            list_type,
-            values,
+            values: values.into(),
             line_names,
-            auto_repeat,
+            auto_repeat_index: self.auto_repeat_index,
         })
     }
 }
diff --git a/components/style/values/computed/mod.rs b/components/style/values/computed/mod.rs
index 7cfe0de6d8d4..bd78d376b35f 100644
--- a/components/style/values/computed/mod.rs
+++ b/components/style/values/computed/mod.rs
@@ -7,6 +7,7 @@
 use self::transform::DirectionVector;
 use super::animated::ToAnimatedValue;
 use super::generics::grid::GridTemplateComponent as GenericGridTemplateComponent;
+use super::generics::grid::ImplicitGridTracks as GenericImplicitGridTracks;
 use super::generics::grid::{GenericGridLine, GenericTrackBreadth};
 use super::generics::grid::{GenericTrackSize, TrackList as GenericTrackList};
 use super::generics::transform::IsParallelTo;
@@ -68,17 +69,17 @@ pub use self::list::Quotes;
 pub use self::motion::{OffsetPath, OffsetRotate};
 pub use self::outline::OutlineStyle;
 pub use self::percentage::{NonNegativePercentage, Percentage};
-pub use self::position::{GridAutoFlow, GridTemplateAreas, Position, ZIndex};
+pub use self::position::{GridAutoFlow, GridTemplateAreas, Position, PositionOrAuto, ZIndex};
 pub use self::rect::NonNegativeLengthOrNumberRect;
 pub use self::resolution::Resolution;
 pub use self::svg::MozContextProperties;
 pub use self::svg::{SVGLength, SVGOpacity, SVGPaint, SVGPaintKind};
 pub use self::svg::{SVGPaintOrder, SVGStrokeDashArray, SVGWidth};
 pub use self::table::XSpan;
-pub use self::text::TextDecorationSkipInk;
 pub use self::text::{InitialLetter, LetterSpacing, LineBreak, LineHeight};
 pub use self::text::{OverflowWrap, TextOverflow, WordBreak, WordSpacing};
 pub use self::text::{TextAlign, TextEmphasisPosition, TextEmphasisStyle};
+pub use self::text::{TextDecorationLength, TextDecorationSkipInk};
 pub use self::time::Time;
 pub use self::transform::{Rotate, Scale, Transform, TransformOperation};
 pub use self::transform::{TransformOrigin, TransformStyle, Translate};
@@ -467,6 +468,7 @@ trivial_to_computed_value!(i32);
 trivial_to_computed_value!(u8);
 trivial_to_computed_value!(u16);
 trivial_to_computed_value!(u32);
+trivial_to_computed_value!(usize);
 trivial_to_computed_value!(Atom);
 #[cfg(feature = "servo")]
 trivial_to_computed_value!(Prefix);
@@ -695,6 +697,9 @@ pub type TrackBreadth = GenericTrackBreadth<LengthPercentage>;
 /// The computed value of a grid `<track-size>`
 pub type TrackSize = GenericTrackSize<LengthPercentage>;
 
+/// The computed value of a grid `<track-size>+`
+pub type ImplicitGridTracks = GenericImplicitGridTracks<TrackSize>;
+
 /// The computed value of a grid `<track-list>`
 /// (could also be `<auto-track-list>` or `<explicit-track-list>`)
 pub type TrackList = GenericTrackList<LengthPercentage, Integer>;
diff --git a/components/style/values/computed/position.rs b/components/style/values/computed/position.rs
index f0f8fe198a64..7b22c37f73f2 100644
--- a/components/style/values/computed/position.rs
+++ b/components/style/values/computed/position.rs
@@ -9,6 +9,7 @@
 
 use crate::values::computed::{Integer, LengthPercentage, Percentage};
 use crate::values::generics::position::Position as GenericPosition;
+use crate::values::generics::position::PositionOrAuto as GenericPositionOrAuto;
 use crate::values::generics::position::ZIndex as GenericZIndex;
 pub use crate::values::specified::position::{GridAutoFlow, GridTemplateAreas};
 use crate::Zero;
@@ -18,6 +19,9 @@ use style_traits::{CssWriter, ToCss};
 /// The computed value of a CSS `<position>`
 pub type Position = GenericPosition<HorizontalPosition, VerticalPosition>;
 
+/// The computed value of an `auto | <position>`
+pub type PositionOrAuto = GenericPositionOrAuto<Position>;
+
 /// The computed value of a CSS horizontal position.
 pub type HorizontalPosition = LengthPercentage;
 
diff --git a/components/style/values/computed/text.rs b/components/style/values/computed/text.rs
index 7201c1aff611..bdb2ac507bc7 100644
--- a/components/style/values/computed/text.rs
+++ b/components/style/values/computed/text.rs
@@ -10,7 +10,7 @@ use crate::values::computed::length::{Length, LengthPercentage};
 use crate::values::computed::{Context, NonNegativeLength, NonNegativeNumber, ToComputedValue};
 use crate::values::generics::text::InitialLetter as GenericInitialLetter;
 use crate::values::generics::text::LineHeight as GenericLineHeight;
-use crate::values::generics::text::Spacing;
+use crate::values::generics::text::{GenericTextDecorationLength, Spacing};
 use crate::values::specified::text::{self as specified, TextOverflowSide};
 use crate::values::specified::text::{TextEmphasisFillMode, TextEmphasisShapeKeyword};
 use crate::values::{CSSFloat, CSSInteger};
@@ -26,6 +26,9 @@ pub use crate::values::specified::{TextDecorationSkipInk, TextTransform};
 /// A computed value for the `initial-letter` property.
 pub type InitialLetter = GenericInitialLetter<CSSFloat, CSSInteger>;
 
+/// Implements type for `text-underline-offset` and `text-decoration-thickness` properties
+pub type TextDecorationLength = GenericTextDecorationLength<Length>;
+
 /// A computed value for the `letter-spacing` property.
 #[repr(transparent)]
 #[derive(
@@ -194,22 +197,21 @@ impl TextDecorationsInEffect {
     }
 }
 
-/// computed value for the text-emphasis-style property
+/// Computed value for the text-emphasis-style property
+///
+/// cbindgen:derive-tagged-enum-copy-constructor=true
 #[derive(Clone, Debug, MallocSizeOf, PartialEq, ToCss, ToResolvedValue)]
+#[allow(missing_docs)]
+#[repr(C, u8)]
 pub enum TextEmphasisStyle {
-    /// Keyword value for the text-emphasis-style property (`filled` `open`)
-    Keyword(TextEmphasisKeywordValue),
+    /// [ <fill> || <shape> ]
+    Keyword {
+        #[css(skip_if = "TextEmphasisFillMode::is_filled")]
+        fill: TextEmphasisFillMode,
+        shape: TextEmphasisShapeKeyword,
+    },
     /// `none`
     None,
-    /// String (will be used only first grapheme cluster) for the text-emphasis-style property
-    String(String),
-}
-
-/// Keyword value for the text-emphasis-style property
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, ToCss, ToResolvedValue)]
-pub struct TextEmphasisKeywordValue {
-    /// fill for the text-emphasis-style property
-    pub fill: TextEmphasisFillMode,
-    /// shape for the text-emphasis-style property
-    pub shape: TextEmphasisShapeKeyword,
+    /// `<string>` (of which only the first grapheme cluster will be used).
+    String(crate::OwnedStr),
 }
diff --git a/components/style/values/generics/easing.rs b/components/style/values/generics/easing.rs
index aab2ef547bac..b234b6a54e00 100644
--- a/components/style/values/generics/easing.rs
+++ b/components/style/values/generics/easing.rs
@@ -69,8 +69,7 @@ pub enum TimingKeyword {
 
 #[cfg(feature = "gecko")]
 fn step_position_jump_enabled(_context: &ParserContext) -> bool {
-    use crate::gecko_bindings::structs;
-    unsafe { structs::StaticPrefs::sVarCache_layout_css_step_position_jump_enabled }
+    static_prefs::pref!("layout.css.step-position-jump.enabled")
 }
 
 #[cfg(feature = "servo")]
diff --git a/components/style/values/generics/font.rs b/components/style/values/generics/font.rs
index 59907ff79201..eb8eac191f00 100644
--- a/components/style/values/generics/font.rs
+++ b/components/style/values/generics/font.rs
@@ -253,9 +253,7 @@ pub enum KeywordSize {
     XLarge,
     #[css(keyword = "xx-large")]
     XXLarge,
-    // This is not a real font keyword and will not parse
-    // HTML font-size 7 corresponds to this value
-    #[css(skip)]
+    #[css(keyword = "xxx-large")]
     XXXLarge,
 }
 
diff --git a/components/style/values/generics/grid.rs b/components/style/values/generics/grid.rs
index 7de109141fe8..b9e173ea50f3 100644
--- a/components/style/values/generics/grid.rs
+++ b/components/style/values/generics/grid.rs
@@ -12,7 +12,7 @@ use crate::values::{CSSFloat, CustomIdent};
 use crate::{Atom, Zero};
 use cssparser::Parser;
 use std::fmt::{self, Write};
-use std::{cmp, mem, usize};
+use std::{cmp, usize};
 use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
 
 /// These are the limits that we choose to clamp grid line numbers to.
@@ -290,16 +290,17 @@ impl<L> TrackSize<L> {
     }
 }
 
-impl<L> Default for TrackSize<L> {
-    fn default() -> Self {
-        TrackSize::Breadth(TrackBreadth::Auto)
+impl<L: PartialEq> TrackSize<L> {
+    /// Return true if it is `auto`.
+    #[inline]
+    pub fn is_auto(&self) -> bool {
+        *self == TrackSize::Breadth(TrackBreadth::Auto)
     }
 }
 
-impl<L: PartialEq> TrackSize<L> {
-    /// Returns true if current TrackSize is same as default.
-    pub fn is_default(&self) -> bool {
-        *self == TrackSize::default()
+impl<L> Default for TrackSize<L> {
+    fn default() -> Self {
+        TrackSize::Breadth(TrackBreadth::Auto)
     }
 }
 
@@ -334,6 +335,39 @@ impl<L: ToCss> ToCss for TrackSize<L> {
     }
 }
 
+/// A `<track-size>+`.
+/// We use the empty slice as `auto`, and always parse `auto` as an empty slice.
+/// This means it's impossible to have a slice containing only one auto item.
+#[derive(
+    Clone,
+    Debug,
+    Default,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
+#[repr(transparent)]
+pub struct GenericImplicitGridTracks<T>(
+    #[css(if_empty = "auto", iterable)] pub crate::OwnedSlice<T>,
+);
+
+pub use self::GenericImplicitGridTracks as ImplicitGridTracks;
+
+impl<T: fmt::Debug + Default + PartialEq> ImplicitGridTracks<T> {
+    /// Returns true if current value is same as its initial value (i.e. auto).
+    pub fn is_initial(&self) -> bool {
+        debug_assert_ne!(
+            *self,
+            ImplicitGridTracks(crate::OwnedSlice::from(vec![Default::default()]))
+        );
+        self.0.is_empty()
+    }
+}
+
 /// Helper function for serializing identifiers with a prefix and suffix, used
 /// for serializing <line-names> (in grid).
 pub fn concat_serialize_idents<W>(
@@ -366,6 +400,7 @@ where
 #[derive(
     Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToCss, ToResolvedValue, ToShmem,
 )]
+#[repr(C, u8)]
 pub enum RepeatCount<Integer> {
     /// A positive integer. This is allowed only for `<track-repeat>` and `<fixed-repeat>`
     Number(Integer),
@@ -380,18 +415,15 @@ impl Parse for RepeatCount<specified::Integer> {
         context: &ParserContext,
         input: &mut Parser<'i, 't>,
     ) -> Result<Self, ParseError<'i>> {
-        // Maximum number of repeat is 10000. The greater numbers should be clamped.
-        const MAX_LINE: i32 = 10000;
         if let Ok(mut i) = input.try(|i| specified::Integer::parse_positive(context, i)) {
-            if i.value() > MAX_LINE {
-                i = specified::Integer::new(MAX_LINE);
-            }
-            Ok(RepeatCount::Number(i))
-        } else {
-            try_match_ident_ignore_ascii_case! { input,
-                "auto-fill" => Ok(RepeatCount::AutoFill),
-                "auto-fit" => Ok(RepeatCount::AutoFit),
+            if i.value() > MAX_GRID_LINE {
+                i = specified::Integer::new(MAX_GRID_LINE);
             }
+            return Ok(RepeatCount::Number(i));
+        }
+        try_match_ident_ignore_ascii_case! { input,
+            "auto-fill" => Ok(RepeatCount::AutoFill),
+            "auto-fit" => Ok(RepeatCount::AutoFit),
         }
     }
 }
@@ -411,7 +443,8 @@ impl Parse for RepeatCount<specified::Integer> {
     ToShmem,
 )]
 #[css(function = "repeat")]
-pub struct TrackRepeat<L, I> {
+#[repr(C)]
+pub struct GenericTrackRepeat<L, I> {
     /// The number of times for the value to be repeated (could also be `auto-fit` or `auto-fill`)
     pub count: RepeatCount<I>,
     /// `<line-names>` accompanying `<track_size>` values.
@@ -419,11 +452,13 @@ pub struct TrackRepeat<L, I> {
     /// If there's no `<line-names>`, then it's represented by an empty vector.
     /// For N `<track-size>` values, there will be N+1 `<line-names>`, and so this vector's
     /// length is always one value more than that of the `<track-size>`.
-    pub line_names: Box<[Box<[CustomIdent]>]>,
+    pub line_names: crate::OwnedSlice<crate::OwnedSlice<CustomIdent>>,
     /// `<track-size>` values.
-    pub track_sizes: Vec<TrackSize<L>>,
+    pub track_sizes: crate::OwnedSlice<GenericTrackSize<L>>,
 }
 
+pub use self::GenericTrackRepeat as TrackRepeat;
+
 impl<L: ToCss, I: ToCss> ToCss for TrackRepeat<L, I> {
     fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
     where
@@ -457,46 +492,10 @@ impl<L: ToCss, I: ToCss> ToCss for TrackRepeat<L, I> {
         Ok(())
     }
 }
-impl<L: Clone> TrackRepeat<L, specified::Integer> {
-    /// If the repeat count is numeric, then expand the values and merge accordingly.
-    pub fn expand(&self) -> Self {
-        if let RepeatCount::Number(num) = self.count {
-            let mut line_names = vec![];
-            let mut track_sizes = vec![];
-            let mut prev_names = vec![];
-
-            for _ in 0..num.value() {
-                let mut names_iter = self.line_names.iter();
-                for (size, names) in self.track_sizes.iter().zip(&mut names_iter) {
-                    prev_names.extend_from_slice(&names);
-                    let vec = mem::replace(&mut prev_names, vec![]);
-                    line_names.push(vec.into_boxed_slice());
-                    track_sizes.push(size.clone());
-                }
-
-                if let Some(names) = names_iter.next() {
-                    prev_names.extend_from_slice(&names);
-                }
-            }
-
-            line_names.push(prev_names.into_boxed_slice());
-            TrackRepeat {
-                count: self.count,
-                track_sizes: track_sizes,
-                line_names: line_names.into_boxed_slice(),
-            }
-        } else {
-            // if it's auto-fit/auto-fill, then it's left to the layout.
-            TrackRepeat {
-                count: self.count,
-                track_sizes: self.track_sizes.clone(),
-                line_names: self.line_names.clone(),
-            }
-        }
-    }
-}
 
 /// Track list values. Can be <track-size> or <track-repeat>
+///
+/// cbindgen:derive-tagged-enum-copy-constructor=true
 #[derive(
     Animate,
     Clone,
@@ -509,56 +508,63 @@ impl<L: Clone> TrackRepeat<L, specified::Integer> {
     ToResolvedValue,
     ToShmem,
 )]
-pub enum TrackListValue<LengthPercentage, Integer> {
+#[repr(C, u8)]
+pub enum GenericTrackListValue<LengthPercentage, Integer> {
     /// A <track-size> value.
-    TrackSize(#[animation(field_bound)] TrackSize<LengthPercentage>),
+    TrackSize(#[animation(field_bound)] GenericTrackSize<LengthPercentage>),
     /// A <track-repeat> value.
-    TrackRepeat(#[animation(field_bound)] TrackRepeat<LengthPercentage, Integer>),
+    TrackRepeat(#[animation(field_bound)] GenericTrackRepeat<LengthPercentage, Integer>),
 }
 
-/// The type of a `<track-list>` as determined during parsing.
-///
-/// <https://drafts.csswg.org/css-grid/#typedef-track-list>
-#[derive(Clone, Copy, Debug, MallocSizeOf, PartialEq, ToComputedValue, ToResolvedValue, ToShmem)]
-pub enum TrackListType {
-    /// [`<auto-track-list>`](https://drafts.csswg.org/css-grid/#typedef-auto-track-list)
-    ///
-    /// If this type exists, then the value at the index in `line_names` field in `TrackList`
-    /// has the `<line-names>?` list that comes before `<auto-repeat>`. If it's a specified value,
-    /// then the `repeat()` function (that follows the line names list) is also at the given index
-    /// in `values` field. On the contrary, if it's a computed value, then the `repeat()` function
-    /// is in the `auto_repeat` field.
-    Auto(u16),
-    /// [`<track-list>`](https://drafts.csswg.org/css-grid/#typedef-track-list)
-    Normal,
-    /// [`<explicit-track-list>`](https://drafts.csswg.org/css-grid/#typedef-explicit-track-list)
-    ///
-    /// Note that this is a subset of the normal `<track-list>`, and so it could be used in place
-    /// of the latter.
-    Explicit,
+pub use self::GenericTrackListValue as TrackListValue;
+
+impl<L, I> TrackListValue<L, I> {
+    fn is_repeat(&self) -> bool {
+        matches!(*self, TrackListValue::TrackRepeat(..))
+    }
 }
 
 /// A grid `<track-list>` type.
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-track-list>
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToResolvedValue, ToShmem)]
-pub struct TrackList<LengthPercentage, Integer> {
-    /// The type of this `<track-list>` (auto, explicit or general).
-    ///
-    /// In order to avoid parsing the same value multiple times, this does a single traversal
-    /// and arrives at the type of value it has parsed (or bails out gracefully with an error).
+#[derive(
+    Clone,
+    Debug,
+    MallocSizeOf,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
+)]
+#[repr(C)]
+pub struct GenericTrackList<LengthPercentage, Integer> {
+    /// The index in `values` where our `<auto-repeat>` value is, if in bounds.
     #[css(skip)]
-    pub list_type: TrackListType,
+    pub auto_repeat_index: usize,
     /// A vector of `<track-size> | <track-repeat>` values.
-    pub values: Vec<TrackListValue<LengthPercentage, Integer>>,
+    pub values: crate::OwnedSlice<GenericTrackListValue<LengthPercentage, Integer>>,
     /// `<line-names>` accompanying `<track-size> | <track-repeat>` values.
     ///
     /// If there's no `<line-names>`, then it's represented by an empty vector.
     /// For N values, there will be N+1 `<line-names>`, and so this vector's
     /// length is always one value more than that of the `<track-size>`.
-    pub line_names: Box<[Box<[CustomIdent]>]>,
-    /// `<auto-repeat>` value. There can only be one `<auto-repeat>` in a TrackList.
-    pub auto_repeat: Option<TrackRepeat<LengthPercentage, Integer>>,
+    pub line_names: crate::OwnedSlice<crate::OwnedSlice<CustomIdent>>,
+}
+
+pub use self::GenericTrackList as TrackList;
+
+impl<L, I> TrackList<L, I> {
+    /// Whether this track list is an explicit track list (that is, doesn't have
+    /// any repeat values).
+    pub fn is_explicit(&self) -> bool {
+        !self.values.iter().any(|v| v.is_repeat())
+    }
+
+    /// Whether this track list has an `<auto-repeat>` value.
+    pub fn has_auto_repeat(&self) -> bool {
+        self.auto_repeat_index < self.values.len()
+    }
 }
 
 impl<L: ToCss, I: ToCss> ToCss for TrackList<L, I> {
@@ -566,11 +572,6 @@ impl<L: ToCss, I: ToCss> ToCss for TrackList<L, I> {
     where
         W: Write,
     {
-        let auto_idx = match self.list_type {
-            TrackListType::Auto(i) => i as usize,
-            _ => usize::MAX,
-        };
-
         let mut values_iter = self.values.iter().peekable();
         let mut line_names_iter = self.line_names.iter().peekable();
 
@@ -578,29 +579,20 @@ impl<L: ToCss, I: ToCss> ToCss for TrackList<L, I> {
             let names = line_names_iter.next().unwrap(); // This should exist!
             concat_serialize_idents("[", "]", names, " ", dest)?;
 
-            match self.auto_repeat {
-                Some(ref repeat) if idx == auto_idx => {
+            match values_iter.next() {
+                Some(value) => {
                     if !names.is_empty() {
                         dest.write_str(" ")?;
                     }
 
-                    repeat.to_css(dest)?;
-                },
-                _ => match values_iter.next() {
-                    Some(value) => {
-                        if !names.is_empty() {
-                            dest.write_str(" ")?;
-                        }
-
-                        value.to_css(dest)?;
-                    },
-                    None => break,
+                    value.to_css(dest)?;
                 },
+                None => break,
             }
 
             if values_iter.peek().is_some() ||
                 line_names_iter.peek().map_or(false, |v| !v.is_empty()) ||
-                (idx + 1 == auto_idx)
+                (idx + 1 == self.auto_repeat_index)
             {
                 dest.write_str(" ")?;
             }
@@ -613,7 +605,8 @@ impl<L: ToCss, I: ToCss> ToCss for TrackList<L, I> {
 /// The `<line-name-list>` for subgrids.
 ///
 /// `subgrid [ <line-names> | repeat(<positive-integer> | auto-fill, <line-names>+) ]+`
-/// Old spec: https://www.w3.org/TR/2015/WD-css-grid-1-20150917/#typedef-line-name-list
+///
+/// https://drafts.csswg.org/css-grid-2/#typedef-line-name-list
 #[derive(
     Clone,
     Debug,
@@ -625,11 +618,12 @@ impl<L: ToCss, I: ToCss> ToCss for TrackList<L, I> {
     ToResolvedValue,
     ToShmem,
 )]
+#[repr(C)]
 pub struct LineNameList {
     /// The optional `<line-name-list>`
-    pub names: Box<[Box<[CustomIdent]>]>,
-    /// Indicates the line name that requires `auto-fill`
-    pub fill_idx: Option<u32>,
+    pub names: crate::OwnedSlice<crate::OwnedSlice<CustomIdent>>,
+    /// Indicates the line name that requires `auto-fill`, if in bounds.
+    pub fill_idx: usize,
 }
 
 impl Parse for LineNameList {
@@ -652,13 +646,17 @@ impl Parse for LineNameList {
                     while let Ok(names) = input.try(parse_line_names) {
                         names_list.push(names);
                     }
-
                     Ok((names_list, count))
                 })
             });
 
             if let Ok((mut names_list, count)) = repeat_parse_result {
                 match count {
+                    // FIXME(emilio): we probably shouldn't expand repeat() at
+                    // parse time for subgrid.
+                    //
+                    // Also this doesn't have the merging semantics that
+                    // non-subgrid has... But maybe that's ok?
                     RepeatCount::Number(num) => line_names.extend(
                         names_list
                             .iter()
@@ -676,7 +674,7 @@ impl Parse for LineNameList {
                         let names = names_list.pop().unwrap();
 
                         line_names.push(names);
-                        fill_idx = Some(line_names.len() as u32 - 1);
+                        fill_idx = Some(line_names.len() - 1);
                     },
                     _ => return Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError)),
                 }
@@ -687,9 +685,13 @@ impl Parse for LineNameList {
             }
         }
 
+        if line_names.len() > MAX_GRID_LINE as usize {
+            line_names.truncate(MAX_GRID_LINE as usize);
+        }
+
         Ok(LineNameList {
-            names: line_names.into_boxed_slice(),
-            fill_idx: fill_idx,
+            names: line_names.into(),
+            fill_idx: fill_idx.unwrap_or(usize::MAX),
         })
     }
 }
@@ -700,7 +702,7 @@ impl ToCss for LineNameList {
         W: Write,
     {
         dest.write_str("subgrid")?;
-        let fill_idx = self.fill_idx.map(|v| v as usize).unwrap_or(usize::MAX);
+        let fill_idx = self.fill_idx;
         for (i, names) in self.names.iter().enumerate() {
             if i == fill_idx {
                 dest.write_str(" repeat(auto-fill,")?;
@@ -727,8 +729,8 @@ impl ToCss for LineNameList {
 }
 
 /// Variants for `<grid-template-rows> | <grid-template-columns>`
-/// Subgrid deferred to Level 2 spec due to lack of implementation.
-/// But it's implemented in gecko, so we have to as well.
+///
+/// cbindgen:derive-tagged-enum-copy-constructor=true
 #[derive(
     Animate,
     Clone,
@@ -741,7 +743,8 @@ impl ToCss for LineNameList {
     ToResolvedValue,
     ToShmem,
 )]
-pub enum GridTemplateComponent<L, I> {
+#[repr(C, u8)]
+pub enum GenericGridTemplateComponent<L, I> {
     /// `none` value.
     None,
     /// The grid `<track-list>`
@@ -750,14 +753,16 @@ pub enum GridTemplateComponent<L, I> {
         #[compute(field_bound)]
         #[resolve(field_bound)]
         #[shmem(field_bound)]
-        TrackList<L, I>,
+        Box<GenericTrackList<L, I>>,
     ),
     /// A `subgrid <line-name-list>?`
     /// TODO: Support animations for this after subgrid is addressed in [grid-2] spec.
     #[animation(error)]
-    Subgrid(LineNameList),
+    Subgrid(Box<LineNameList>),
 }
 
+pub use self::GenericGridTemplateComponent as GridTemplateComponent;
+
 impl<L, I> GridTemplateComponent<L, I> {
     /// Returns length of the <track-list>s <track-size>
     pub fn track_list_len(&self) -> usize {
diff --git a/components/style/values/generics/position.rs b/components/style/values/generics/position.rs
index 7e43f439793d..2742dd879136 100644
--- a/components/style/values/generics/position.rs
+++ b/components/style/values/generics/position.rs
@@ -41,6 +41,43 @@ impl<H, V> Position<H, V> {
     }
 }
 
+/// A generic type for representing an `Auto | <position>`.
+/// This is used by <offset-anchor> for now.
+/// https://drafts.fxtf.org/motion-1/#offset-anchor-property
+#[derive(
+    Animate,
+    Clone,
+    ComputeSquaredDistance,
+    Copy,
+    Debug,
+    MallocSizeOf,
+    Parse,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToAnimatedZero,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
+#[repr(C, u8)]
+pub enum GenericPositionOrAuto<Pos> {
+    /// The <position> value.
+    Position(Pos),
+    /// The keyword `auto`.
+    Auto,
+}
+
+pub use self::GenericPositionOrAuto as PositionOrAuto;
+
+impl<Pos> PositionOrAuto<Pos> {
+    /// Return `auto`.
+    #[inline]
+    pub fn auto() -> Self {
+        PositionOrAuto::Auto
+    }
+}
+
 /// A generic value for the `z-index` property.
 #[derive(
     Animate,
diff --git a/components/style/values/generics/text.rs b/components/style/values/generics/text.rs
index b55a9ad62dc5..fd434cc12738 100644
--- a/components/style/values/generics/text.rs
+++ b/components/style/values/generics/text.rs
@@ -72,11 +72,8 @@ impl<Value> Spacing<Value> {
 
 #[cfg(feature = "gecko")]
 fn line_height_moz_block_height_enabled(context: &ParserContext) -> bool {
-    use crate::gecko_bindings::structs;
     context.in_ua_sheet() ||
-        unsafe {
-            structs::StaticPrefs::sVarCache_layout_css_line_height_moz_block_height_content_enabled
-        }
+        static_prefs::pref!("layout.css.line-height-moz-block-height.content.enabled")
 }
 
 /// A generic value for the `line-height` property.
@@ -125,3 +122,33 @@ impl<N, L> LineHeight<N, L> {
         LineHeight::Normal
     }
 }
+
+/// Implements type for text-underline-offset and text-decoration-thickness
+/// which take the grammar of auto | from-font | <length>
+///
+/// https://drafts.csswg.org/css-text-decor-4/
+#[repr(C, u8)]
+#[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
+#[derive(
+    Animate,
+    Clone,
+    Copy,
+    ComputeSquaredDistance,
+    ToAnimatedZero,
+    Debug,
+    Eq,
+    MallocSizeOf,
+    Parse,
+    PartialEq,
+    SpecifiedValueInfo,
+    ToComputedValue,
+    ToCss,
+    ToResolvedValue,
+    ToShmem,
+)]
+#[allow(missing_docs)]
+pub enum GenericTextDecorationLength<L> {
+    Length(L),
+    Auto,
+    FromFont,
+}
diff --git a/components/style/values/resolved/mod.rs b/components/style/values/resolved/mod.rs
index 379ea83ec6b1..e64178a1c957 100644
--- a/components/style/values/resolved/mod.rs
+++ b/components/style/values/resolved/mod.rs
@@ -65,6 +65,7 @@ trivial_to_resolved_value!(u8);
 trivial_to_resolved_value!(i8);
 trivial_to_resolved_value!(u16);
 trivial_to_resolved_value!(u32);
+trivial_to_resolved_value!(usize);
 trivial_to_resolved_value!(String);
 trivial_to_resolved_value!(Box<str>);
 trivial_to_resolved_value!(cssparser::RGBA);
diff --git a/components/style/values/specified/basic_shape.rs b/components/style/values/specified/basic_shape.rs
index 8dccf4594f00..3c32144e71cb 100644
--- a/components/style/values/specified/basic_shape.rs
+++ b/components/style/values/specified/basic_shape.rs
@@ -58,9 +58,7 @@ pub type Polygon = generic::GenericPolygon<LengthPercentage>;
 
 #[cfg(feature = "gecko")]
 fn is_clip_path_path_enabled(context: &ParserContext) -> bool {
-    use crate::gecko_bindings::structs::mozilla;
-    context.chrome_rules_enabled() ||
-        unsafe { mozilla::StaticPrefs::sVarCache_layout_css_clip_path_path_enabled }
+    context.chrome_rules_enabled() || static_prefs::pref!("layout.css.clip-path-path.enabled")
 }
 #[cfg(feature = "servo")]
 fn is_clip_path_path_enabled(_: &ParserContext) -> bool {
diff --git a/components/style/values/specified/box.rs b/components/style/values/specified/box.rs
index 0811a48be1a3..f481b940e052 100644
--- a/components/style/values/specified/box.rs
+++ b/components/style/values/specified/box.rs
@@ -16,6 +16,7 @@ use crate::values::specified::{AllowQuirks, Number};
 use crate::values::{CustomIdent, KeyframesName};
 use crate::Atom;
 use cssparser::Parser;
+use num_traits::FromPrimitive;
 use selectors::parser::SelectorParseErrorKind;
 use std::fmt::{self, Write};
 use style_traits::{CssWriter, KeywordsCollectFn, ParseError};
@@ -23,102 +24,55 @@ use style_traits::{SpecifiedValueInfo, StyleParseErrorKind, ToCss};
 
 #[cfg(feature = "gecko")]
 fn moz_display_values_enabled(context: &ParserContext) -> bool {
-    use crate::gecko_bindings::structs;
     context.in_ua_or_chrome_sheet() ||
-        unsafe { structs::StaticPrefs::sVarCache_layout_css_xul_display_values_content_enabled }
+        static_prefs::pref!("layout.css.xul-display-values.content.enabled")
 }
 
 #[cfg(feature = "gecko")]
 fn moz_box_display_values_enabled(context: &ParserContext) -> bool {
-    use crate::gecko_bindings::structs;
     context.in_ua_or_chrome_sheet() ||
-        unsafe {
-            structs::StaticPrefs::sVarCache_layout_css_xul_box_display_values_content_enabled
-        }
-}
-
-#[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
-fn parse_unimplemented_in_servo_2020(_context: &ParserContext) -> bool {
-    true
-}
-
-#[cfg(feature = "servo-layout-2020")]
-fn parse_unimplemented_in_servo_2020(_context: &ParserContext) -> bool {
-    servo_config::prefs::pref_map()
-        .get("layout.2020.unimplemented")
-        .as_bool()
-        .unwrap_or(false)
+        static_prefs::pref!("layout.css.xul-box-display-values.content.enabled")
 }
 
 /// Defines an element’s display type, which consists of
 /// the two basic qualities of how an element generates boxes
 /// <https://drafts.csswg.org/css-display/#propdef-display>
-///
-///
-/// NOTE(emilio): Order is important in Gecko!
-///
-/// If you change it, make sure to take a look at the
-/// FrameConstructionDataByDisplay stuff (both the XUL and non-XUL version), and
-/// ensure it's still correct!
 #[allow(missing_docs)]
-#[derive(
-    Clone,
-    Copy,
-    Debug,
-    Eq,
-    FromPrimitive,
-    Hash,
-    MallocSizeOf,
-    Parse,
-    PartialEq,
-    SpecifiedValueInfo,
-    ToComputedValue,
-    ToCss,
-    ToResolvedValue,
-    ToShmem,
-)]
-#[cfg_attr(feature = "servo", derive(Deserialize, Serialize))]
+#[derive(Clone, Copy, Debug, Eq, FromPrimitive, Hash, MallocSizeOf, PartialEq, ToCss, ToShmem)]
 #[repr(u8)]
-pub enum Display {
+pub enum DisplayOutside {
     None = 0,
+    Inline,
     Block,
+    TableCaption,
+    InternalTable,
+    #[cfg(feature = "gecko")]
+    InternalRuby,
     #[cfg(feature = "gecko")]
+    XUL,
+}
+
+#[allow(missing_docs)]
+#[derive(Clone, Copy, Debug, Eq, FromPrimitive, Hash, MallocSizeOf, PartialEq, ToCss, ToShmem)]
+#[repr(u8)]
+pub enum DisplayInside {
+    None = 0,
+    #[cfg(feature = "gecko")]
+    Contents,
+    Block,
     FlowRoot,
     Inline,
-    #[parse(condition = "parse_unimplemented_in_servo_2020")]
-    InlineBlock,
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
-    ListItem,
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
+    Flex,
+    #[cfg(feature = "gecko")]
+    Grid,
     Table,
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
-    InlineTable,
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
     TableRowGroup,
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
     TableColumn,
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
     TableColumnGroup,
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
     TableHeaderGroup,
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
     TableFooterGroup,
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
     TableRow,
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
     TableCell,
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
-    TableCaption,
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
-    #[parse(aliases = "-webkit-flex")]
-    Flex,
-    #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
-    #[parse(aliases = "-webkit-inline-flex")]
-    InlineFlex,
-    #[cfg(feature = "gecko")]
-    Grid,
-    #[cfg(feature = "gecko")]
-    InlineGrid,
     #[cfg(feature = "gecko")]
     Ruby,
     #[cfg(feature = "gecko")]
@@ -130,46 +84,216 @@ pub enum Display {
     #[cfg(feature = "gecko")]
     RubyTextContainer,
     #[cfg(feature = "gecko")]
-    Contents,
-    #[cfg(feature = "gecko")]
     WebkitBox,
     #[cfg(feature = "gecko")]
-    WebkitInlineBox,
-    #[cfg(feature = "gecko")]
-    #[parse(condition = "moz_box_display_values_enabled")]
     MozBox,
     #[cfg(feature = "gecko")]
-    #[parse(condition = "moz_box_display_values_enabled")]
     MozInlineBox,
     #[cfg(feature = "gecko")]
-    #[parse(condition = "moz_display_values_enabled")]
     MozGrid,
     #[cfg(feature = "gecko")]
-    #[parse(condition = "moz_display_values_enabled")]
     MozInlineGrid,
     #[cfg(feature = "gecko")]
-    #[parse(condition = "moz_display_values_enabled")]
     MozGridGroup,
     #[cfg(feature = "gecko")]
-    #[parse(condition = "moz_display_values_enabled")]
     MozGridLine,
     #[cfg(feature = "gecko")]
-    #[parse(condition = "moz_display_values_enabled")]
     MozStack,
     #[cfg(feature = "gecko")]
-    #[parse(condition = "moz_display_values_enabled")]
     MozInlineStack,
     #[cfg(feature = "gecko")]
-    #[parse(condition = "moz_display_values_enabled")]
     MozDeck,
     #[cfg(feature = "gecko")]
-    #[parse(condition = "moz_display_values_enabled")]
     MozGroupbox,
     #[cfg(feature = "gecko")]
-    #[parse(condition = "moz_display_values_enabled")]
     MozPopup,
+    Flow, // only used for parsing, not computed value
+}
+
+#[allow(missing_docs)]
+#[derive(
+    Clone,
+    Copy,
+    Debug,
+    Eq,
+    FromPrimitive,
+    Hash,
+    MallocSizeOf,
+    PartialEq,
+    ToComputedValue,
+    ToResolvedValue,
+    ToShmem,
+)]
+#[repr(transparent)]
+pub struct Display(u16);
+
+/// Gecko-only impl block for Display (shared stuff later in this file):
+#[allow(missing_docs)]
+#[allow(non_upper_case_globals)]
+impl Display {
+    // Our u16 bits are used as follows:    LOOOOOOOIIIIIIII
+    const LIST_ITEM_BIT: u16 = 0x8000; //^
+    const DISPLAY_OUTSIDE_BITS: u16 = 7; // ^^^^^^^
+    const DISPLAY_INSIDE_BITS: u16 = 8; //        ^^^^^^^^
+
+    /// https://drafts.csswg.org/css-display/#the-display-properties
+    pub const None: Self = Self::new(DisplayOutside::None, DisplayInside::None);
+    #[cfg(feature = "gecko")]
+    pub const Contents: Self = Self::new(DisplayOutside::None, DisplayInside::Contents);
+    pub const Inline: Self = Self::new(DisplayOutside::Inline, DisplayInside::Inline);
+    pub const InlineBlock: Self = Self::new(DisplayOutside::Inline, DisplayInside::FlowRoot);
+    pub const Block: Self = Self::new(DisplayOutside::Block, DisplayInside::Block);
+    #[cfg(feature = "gecko")]
+    pub const FlowRoot: Self = Self::new(DisplayOutside::Block, DisplayInside::FlowRoot);
+    pub const Flex: Self = Self::new(DisplayOutside::Block, DisplayInside::Flex);
+    pub const InlineFlex: Self = Self::new(DisplayOutside::Inline, DisplayInside::Flex);
+    #[cfg(feature = "gecko")]
+    pub const Grid: Self = Self::new(DisplayOutside::Block, DisplayInside::Grid);
+    #[cfg(feature = "gecko")]
+    pub const InlineGrid: Self = Self::new(DisplayOutside::Inline, DisplayInside::Grid);
+    pub const Table: Self = Self::new(DisplayOutside::Block, DisplayInside::Table);
+    pub const InlineTable: Self = Self::new(DisplayOutside::Inline, DisplayInside::Table);
+    pub const TableCaption: Self = Self::new(DisplayOutside::TableCaption, DisplayInside::Block);
+    #[cfg(feature = "gecko")]
+    pub const Ruby: Self = Self::new(DisplayOutside::Inline, DisplayInside::Ruby);
+    #[cfg(feature = "gecko")]
+    pub const WebkitBox: Self = Self::new(DisplayOutside::Block, DisplayInside::WebkitBox);
+    #[cfg(feature = "gecko")]
+    pub const WebkitInlineBox: Self = Self::new(DisplayOutside::Inline, DisplayInside::WebkitBox);
+    /// Internal table boxes.
+    pub const TableRowGroup: Self =
+        Self::new(DisplayOutside::InternalTable, DisplayInside::TableRowGroup);
+    pub const TableHeaderGroup: Self = Self::new(
+        DisplayOutside::InternalTable,
+        DisplayInside::TableHeaderGroup,
+    );
+    pub const TableFooterGroup: Self = Self::new(
+        DisplayOutside::InternalTable,
+        DisplayInside::TableFooterGroup,
+    );
+    pub const TableColumn: Self =
+        Self::new(DisplayOutside::InternalTable, DisplayInside::TableColumn);
+    pub const TableColumnGroup: Self = Self::new(
+        DisplayOutside::InternalTable,
+        DisplayInside::TableColumnGroup,
+    );
+    pub const TableRow: Self = Self::new(DisplayOutside::InternalTable, DisplayInside::TableRow);
+
+    pub const TableCell: Self = Self::new(DisplayOutside::InternalTable, DisplayInside::TableCell);
+
+    /// Internal ruby boxes.
+    #[cfg(feature = "gecko")]
+    pub const RubyBase: Self = Self::new(DisplayOutside::InternalRuby, DisplayInside::RubyBase);
+    #[cfg(feature = "gecko")]
+    pub const RubyBaseContainer: Self = Self::new(
+        DisplayOutside::InternalRuby,
+        DisplayInside::RubyBaseContainer,
+    );
+    #[cfg(feature = "gecko")]
+    pub const RubyText: Self = Self::new(DisplayOutside::InternalRuby, DisplayInside::RubyText);
+    #[cfg(feature = "gecko")]
+    pub const RubyTextContainer: Self = Self::new(
+        DisplayOutside::InternalRuby,
+        DisplayInside::RubyTextContainer,
+    );
+
+    /// XUL boxes.
+    #[cfg(feature = "gecko")]
+    pub const MozBox: Self = Self::new(DisplayOutside::XUL, DisplayInside::MozBox);
+    #[cfg(feature = "gecko")]
+    pub const MozInlineBox: Self = Self::new(DisplayOutside::XUL, DisplayInside::MozInlineBox);
+    #[cfg(feature = "gecko")]
+    pub const MozGrid: Self = Self::new(DisplayOutside::XUL, DisplayInside::MozGrid);
+    #[cfg(feature = "gecko")]
+    pub const MozInlineGrid: Self = Self::new(DisplayOutside::XUL, DisplayInside::MozInlineGrid);
+    #[cfg(feature = "gecko")]
+    pub const MozGridGroup: Self = Self::new(DisplayOutside::XUL, DisplayInside::MozGridGroup);
+    #[cfg(feature = "gecko")]
+    pub const MozGridLine: Self = Self::new(DisplayOutside::XUL, DisplayInside::MozGridLine);
+    #[cfg(feature = "gecko")]
+    pub const MozStack: Self = Self::new(DisplayOutside::XUL, DisplayInside::MozStack);
+    #[cfg(feature = "gecko")]
+    pub const MozInlineStack: Self = Self::new(DisplayOutside::XUL, DisplayInside::MozInlineStack);
+    #[cfg(feature = "gecko")]
+    pub const MozDeck: Self = Self::new(DisplayOutside::XUL, DisplayInside::MozDeck);
+    #[cfg(feature = "gecko")]
+    pub const MozGroupbox: Self = Self::new(DisplayOutside::XUL, DisplayInside::MozGroupbox);
+    #[cfg(feature = "gecko")]
+    pub const MozPopup: Self = Self::new(DisplayOutside::XUL, DisplayInside::MozPopup);
+
+    /// Make a raw display value from <display-outside> and <display-inside> values.
+    #[inline]
+    const fn new(outside: DisplayOutside, inside: DisplayInside) -> Self {
+        let o: u16 = ((outside as u8) as u16) << Self::DISPLAY_INSIDE_BITS;
+        let i: u16 = (inside as u8) as u16;
+        Self(o | i)
+    }
+
+    /// Make a display enum value from <display-outside> and <display-inside> values.
+    /// We store `flow` as a synthetic `block` or `inline` inside-value to simplify
+    /// our layout code.
+    #[inline]
+    fn from3(outside: DisplayOutside, inside: DisplayInside, list_item: bool) -> Self {
+        let inside = match inside {
+            DisplayInside::Flow => match outside {
+                DisplayOutside::Inline => DisplayInside::Inline,
+                _ => DisplayInside::Block,
+            },
+            _ => inside,
+        };
+        let v = Self::new(outside, inside);
+        if !list_item {
+            return v;
+        }
+        Self(v.0 | Self::LIST_ITEM_BIT)
+    }
+
+    /// Accessor for the <display-inside> value.
+    #[inline]
+    pub fn inside(&self) -> DisplayInside {
+        DisplayInside::from_u16(self.0 & ((1 << Self::DISPLAY_INSIDE_BITS) - 1)).unwrap()
+    }
+
+    /// Accessor for the <display-outside> value.
+    #[inline]
+    pub fn outside(&self) -> DisplayOutside {
+        DisplayOutside::from_u16(
+            (self.0 >> Self::DISPLAY_INSIDE_BITS) & ((1 << Self::DISPLAY_OUTSIDE_BITS) - 1),
+        )
+        .unwrap()
+    }
+
+    /// Returns whether this `display` value is some kind of list-item.
+    #[inline]
+    pub const fn is_list_item(&self) -> bool {
+        (self.0 & Self::LIST_ITEM_BIT) != 0
+    }
+
+    /// Returns whether this `display` value is a ruby level container.
+    pub fn is_ruby_level_container(&self) -> bool {
+        match *self {
+            #[cfg(feature = "gecko")]
+            Display::RubyBaseContainer | Display::RubyTextContainer => true,
+            _ => false,
+        }
+    }
+
+    /// Returns whether this `display` value is one of the types for ruby.
+    pub fn is_ruby_type(&self) -> bool {
+        match self.inside() {
+            #[cfg(feature = "gecko")]
+            DisplayInside::Ruby |
+            DisplayInside::RubyBase |
+            DisplayInside::RubyText |
+            DisplayInside::RubyBaseContainer |
+            DisplayInside::RubyTextContainer => true,
+            _ => false,
+        }
+    }
 }
 
+/// Shared Display impl for both Gecko and Servo.
+#[allow(non_upper_case_globals)]
 impl Display {
     /// The initial display value.
     #[inline]
@@ -183,22 +307,20 @@ impl Display {
     pub fn is_atomic_inline_level(&self) -> bool {
         match *self {
             Display::InlineBlock => true,
-            #[cfg(feature = "servo-layout-2013")]
             Display::InlineFlex | Display::InlineTable => true,
             _ => false,
         }
     }
 
-    /// Returns whether this "display" value is the display of a flex or
+    /// Returns whether this `display` value is the display of a flex or
     /// grid container.
     ///
     /// This is used to implement various style fixups.
     pub fn is_item_container(&self) -> bool {
-        match *self {
-            #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
-            Display::Flex | Display::InlineFlex => true,
+        match self.inside() {
+            DisplayInside::Flex => true,
             #[cfg(feature = "gecko")]
-            Display::Grid | Display::InlineGrid => true,
+            DisplayInside::Grid => true,
             _ => false,
         }
     }
@@ -215,80 +337,50 @@ impl Display {
         }
     }
 
-    /// Returns whether this "display" value is one of the types for
-    /// ruby.
-    #[cfg(feature = "gecko")]
-    pub fn is_ruby_type(&self) -> bool {
-        matches!(
-            *self,
-            Display::Ruby |
-                Display::RubyBase |
-                Display::RubyText |
-                Display::RubyBaseContainer |
-                Display::RubyTextContainer
-        )
-    }
-
-    /// Returns whether this "display" value is a ruby level container.
-    #[cfg(feature = "gecko")]
-    pub fn is_ruby_level_container(&self) -> bool {
-        matches!(
-            *self,
-            Display::RubyBaseContainer | Display::RubyTextContainer
-        )
-    }
-
     /// Convert this display into an equivalent block display.
     ///
-    /// Also used for style adjustments.
+    /// Also used for :root style adjustments.
     pub fn equivalent_block_display(&self, _is_root_element: bool) -> Self {
-        match *self {
-            // Values that have a corresponding block-outside version.
-            #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
-            Display::InlineTable => Display::Table,
-            #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
-            Display::InlineFlex => Display::Flex,
-
-            #[cfg(feature = "gecko")]
-            Display::InlineGrid => Display::Grid,
-            #[cfg(feature = "gecko")]
-            Display::WebkitInlineBox => Display::WebkitBox,
-
-            // Special handling for contents and list-item on the root
-            // element for Gecko.
-            #[cfg(feature = "gecko")]
-            Display::Contents | Display::ListItem if _is_root_element => Display::Block,
-
-            // These are not changed by blockification.
-            Display::None | Display::Block => *self,
-            #[cfg(any(feature = "gecko", feature = "servo-layout-2013"))]
-            Display::Flex | Display::ListItem | Display::Table => *self,
-
-            #[cfg(feature = "gecko")]
-            Display::Contents | Display::FlowRoot | Display::Grid | Display::WebkitBox => *self,
+        #[cfg(feature = "gecko")]
+        {
+            // Special handling for `contents` and `list-item`s on the root element.
+            if _is_root_element && (self.is_contents() || self.is_list_item()) {
+                return Display::Block;
+            }
+        }
 
-            // Everything else becomes block.
+        match self.outside() {
+            DisplayOutside::Inline => {
+                let inside = match self.inside() {
+                    DisplayInside::Inline | DisplayInside::FlowRoot => DisplayInside::Block,
+                    inside => inside,
+                };
+                Display::from3(DisplayOutside::Block, inside, self.is_list_item())
+            },
+            DisplayOutside::Block | DisplayOutside::None => *self,
             _ => Display::Block,
         }
     }
 
-    /// Convert this display into an inline-outside display.
-    ///
-    /// Ideally it should implement spec: https://drafts.csswg.org/css-display/#inlinify
-    /// but the spec isn't stable enough, so we copy what Gecko does for now.
+    /// Convert this display into an equivalent inline-outside display.
+    /// https://drafts.csswg.org/css-display/#inlinify
     #[cfg(feature = "gecko")]
     pub fn inlinify(&self) -> Self {
-        match *self {
-            Display::Block | Display::FlowRoot => Display::InlineBlock,
-            Display::Table => Display::InlineTable,
-            Display::Flex => Display::InlineFlex,
-            Display::Grid => Display::InlineGrid,
-            // XXX bug 1105868 this should probably be InlineListItem:
-            Display::ListItem => Display::Inline,
-            Display::MozBox => Display::MozInlineBox,
-            Display::MozStack => Display::MozInlineStack,
-            Display::WebkitBox => Display::WebkitInlineBox,
-            other => other,
+        match self.outside() {
+            DisplayOutside::Block => {
+                let inside = match self.inside() {
+                    DisplayInside::Block => DisplayInside::FlowRoot,
+                    inside => inside,
+                };
+                Display::from3(DisplayOutside::Inline, inside, self.is_list_item())
+            },
+            #[cfg(feature = "gecko")]
+            DisplayOutside::XUL => match self.inside() {
+                DisplayInside::MozBox => Display::MozInlineBox,
+                DisplayInside::MozStack => Display::MozInlineStack,
+                _ => *self,
+            },
+            _ => *self,
         }
     }
 
@@ -309,6 +401,263 @@ impl Display {
     }
 }
 
+impl ToCss for Display {
+    fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
+    where
+        W: fmt::Write,
+    {
+        debug_assert_ne!(
+            self.inside(),
+            DisplayInside::Flow,
+            "`flow` never appears in `display` computed value"
+        );
+        let outside = self.outside();
+        let inside = match self.inside() {
+            DisplayInside::Block | DisplayInside::Inline => DisplayInside::Flow,
+            inside => inside,
+        };
+        match *self {
+            Display::Block | Display::Inline => outside.to_css(dest),
+            Display::InlineBlock => dest.write_str("inline-block"),
+            #[cfg(feature = "gecko")]
+            Display::WebkitInlineBox => dest.write_str("-webkit-inline-box"),
+            #[cfg(feature = "gecko")]
+            Display::MozInlineBox => dest.write_str("-moz-inline-box"),
+            #[cfg(feature = "gecko")]
+            Display::MozInlineGrid => dest.write_str("-moz-inline-grid"),
+            #[cfg(feature = "gecko")]
+            Display::MozInlineStack => dest.write_str("-moz-inline-stack"),
+            Display::TableCaption => dest.write_str("table-caption"),
+            _ => match (outside, inside) {
+                #[cfg(feature = "gecko")]
+                (DisplayOutside::Inline, DisplayInside::Grid) => dest.write_str("inline-grid"),
+                (DisplayOutside::Inline, DisplayInside::Flex) |
+                (DisplayOutside::Inline, DisplayInside::Table) => {
+                    dest.write_str("inline-")?;
+                    inside.to_css(dest)
+                },
+                #[cfg(feature = "gecko")]
+                (DisplayOutside::Block, DisplayInside::Ruby) => dest.write_str("block ruby"),
+                (_, inside) => {
+                    if self.is_list_item() {
+                        if outside != DisplayOutside::Block {
+                            outside.to_css(dest)?;
+                            dest.write_str(" ")?;
+                        }
+                        if inside != DisplayInside::Flow {
+                            inside.to_css(dest)?;
+                            dest.write_str(" ")?;
+                        }
+                        dest.write_str("list-item")
+                    } else {
+                        inside.to_css(dest)
+                    }
+                },
+            },
+        }
+    }
+}
+
+/// <display-inside> = flow | flow-root | table | flex | grid | ruby
+/// https://drafts.csswg.org/css-display/#typedef-display-inside
+fn parse_display_inside<'i, 't>(
+    input: &mut Parser<'i, 't>,
+) -> Result<DisplayInside, ParseError<'i>> {
+    Ok(try_match_ident_ignore_ascii_case! { input,
+        "flow" => DisplayInside::Flow,
+        #[cfg(feature = "gecko")]
+        "flow-root" => DisplayInside::FlowRoot,
+        "table" => DisplayInside::Table,
+        "flex" => DisplayInside::Flex,
+        #[cfg(feature = "gecko")]
+        "grid" => DisplayInside::Grid,
+        #[cfg(feature = "gecko")]
+        "ruby" => DisplayInside::Ruby,
+    })
+}
+
+/// <display-outside> = block | inline | run-in
+/// https://drafts.csswg.org/css-display/#typedef-display-outside
+fn parse_display_outside<'i, 't>(
+    input: &mut Parser<'i, 't>,
+) -> Result<DisplayOutside, ParseError<'i>> {
+    Ok(try_match_ident_ignore_ascii_case! { input,
+        "block" => DisplayOutside::Block,
+        "inline" => DisplayOutside::Inline,
+        // FIXME(bug 2056): not supported in layout yet:
+        //"run-in" => DisplayOutside::RunIn,
+    })
+}
+
+/// (flow | flow-root)?
+fn parse_display_inside_for_list_item<'i, 't>(
+    input: &mut Parser<'i, 't>,
+) -> Result<DisplayInside, ParseError<'i>> {
+    Ok(try_match_ident_ignore_ascii_case! { input,
+        "flow" => DisplayInside::Flow,
+        #[cfg(feature = "gecko")]
+        "flow-root" => DisplayInside::FlowRoot,
+    })
+}
+/// Test a <display-inside> Result for same values as above.
+fn is_valid_inside_for_list_item<'i>(inside: &Result<DisplayInside, ParseError<'i>>) -> bool {
+    match inside {
+        Ok(DisplayInside::Flow) => true,
+        #[cfg(feature = "gecko")]
+        Ok(DisplayInside::FlowRoot) => true,
+        _ => false,
+    }
+}
+
+/// Parse `list-item`.
+fn parse_list_item<'i, 't>(input: &mut Parser<'i, 't>) -> Result<(), ParseError<'i>> {
+    Ok(try_match_ident_ignore_ascii_case! { input,
+        "list-item" => (),
+    })
+}
+
+impl Parse for Display {
+    #[allow(unused)] // `context` isn't used for servo-2020 for now
+    fn parse<'i, 't>(
+        context: &ParserContext,
+        input: &mut Parser<'i, 't>,
+    ) -> Result<Display, ParseError<'i>> {
+        // Parse all combinations of <display-inside/outside>? and `list-item`? first.
+        let mut got_list_item = input.try(parse_list_item).is_ok();
+        let mut inside = if got_list_item {
+            input.try(parse_display_inside_for_list_item)
+        } else {
+            input.try(parse_display_inside)
+        };
+        // <display-listitem> = <display-outside>? && [ flow | flow-root ]? && list-item
+        // https://drafts.csswg.org/css-display/#typedef-display-listitem
+        if !got_list_item && is_valid_inside_for_list_item(&inside) {
+            got_list_item = input.try(parse_list_item).is_ok();
+        }
+        let outside = input.try(parse_display_outside);
+        if outside.is_ok() {
+            if !got_list_item && (inside.is_err() || is_valid_inside_for_list_item(&inside)) {
+                got_list_item = input.try(parse_list_item).is_ok();
+            }
+            if inside.is_err() {
+                inside = if got_list_item {
+                    input.try(parse_display_inside_for_list_item)
+                } else {
+                    input.try(parse_display_inside)
+                };
+                if !got_list_item && is_valid_inside_for_list_item(&inside) {
+                    got_list_item = input.try(parse_list_item).is_ok();
+                }
+            }
+        }
+        if got_list_item || inside.is_ok() || outside.is_ok() {
+            let inside = inside.unwrap_or(DisplayInside::Flow);
+            let outside = outside.unwrap_or(match inside {
+                // "If <display-outside> is omitted, the element’s outside display type
+                // defaults to block — except for ruby, which defaults to inline."
+                // https://drafts.csswg.org/css-display/#inside-model
+                #[cfg(feature = "gecko")]
+                DisplayInside::Ruby => DisplayOutside::Inline,
+                _ => DisplayOutside::Block,
+            });
+            return Ok(Display::from3(outside, inside, got_list_item));
+        }
+
+        // Now parse the single-keyword `display` values.
+        Ok(try_match_ident_ignore_ascii_case! { input,
+            "none" => Display::None,
+            #[cfg(feature = "gecko")]
+            "contents" => Display::Contents,
+            "inline-block" => Display::InlineBlock,
+            "inline-table" => Display::InlineTable,
+            "-webkit-flex" => Display::Flex,
+            "inline-flex" | "-webkit-inline-flex" => Display::InlineFlex,
+            #[cfg(feature = "gecko")]
+            "inline-grid" => Display::InlineGrid,
+            "table-caption" => Display::TableCaption,
+            "table-row-group" => Display::TableRowGroup,
+            "table-header-group" => Display::TableHeaderGroup,
+            "table-footer-group" => Display::TableFooterGroup,
+            "table-column" => Display::TableColumn,
+            "table-column-group" => Display::TableColumnGroup,
+            "table-row" => Display::TableRow,
+            "table-cell" => Display::TableCell,
+            #[cfg(feature = "gecko")]
+            "ruby-base" => Display::RubyBase,
+            #[cfg(feature = "gecko")]
+            "ruby-base-container" => Display::RubyBaseContainer,
+            #[cfg(feature = "gecko")]
+            "ruby-text" => Display::RubyText,
+            #[cfg(feature = "gecko")]
+            "ruby-text-container" => Display::RubyTextContainer,
+            #[cfg(feature = "gecko")]
+            "-webkit-box" => Display::WebkitBox,
+            #[cfg(feature = "gecko")]
+            "-webkit-inline-box" => Display::WebkitInlineBox,
+            #[cfg(feature = "gecko")]
+            "-moz-box" if moz_box_display_values_enabled(context) => Display::MozBox,
+            #[cfg(feature = "gecko")]
+            "-moz-inline-box" if moz_box_display_values_enabled(context) => Display::MozInlineBox,
+            #[cfg(feature = "gecko")]
+            "-moz-grid" if moz_display_values_enabled(context) => Display::MozGrid,
+            #[cfg(feature = "gecko")]
+            "-moz-inline-grid" if moz_display_values_enabled(context) => Display::MozInlineGrid,
+            #[cfg(feature = "gecko")]
+            "-moz-grid-group" if moz_display_values_enabled(context) => Display::MozGridGroup,
+            #[cfg(feature = "gecko")]
+            "-moz-grid-line" if moz_display_values_enabled(context) => Display::MozGridLine,
+            #[cfg(feature = "gecko")]
+            "-moz-stack" if moz_display_values_enabled(context) => Display::MozStack,
+            #[cfg(feature = "gecko")]
+            "-moz-inline-stack" if moz_display_values_enabled(context) => Display::MozInlineStack,
+            #[cfg(feature = "gecko")]
+            "-moz-deck" if moz_display_values_enabled(context) => Display::MozDeck,
+            #[cfg(feature = "gecko")]
+            "-moz-groupbox" if moz_display_values_enabled(context) => Display::MozGroupbox,
+            #[cfg(feature = "gecko")]
+            "-moz-popup" if moz_display_values_enabled(context) => Display::MozPopup,
+        })
+    }
+}
+
+impl SpecifiedValueInfo for Display {
+    fn collect_completion_keywords(f: KeywordsCollectFn) {
+        f(&[
+            "block",
+            "contents",
+            "flex",
+            "flow-root",
+            "grid",
+            "inline",
+            "inline-block",
+            "inline-flex",
+            "inline-grid",
+            "inline-table",
+            "inline list-item",
+            "inline flow-root list-item",
+            "list-item",
+            "none",
+            "block ruby",
+            "ruby",
+            "ruby-base",
+            "ruby-base-container",
+            "ruby-text",
+            "ruby-text-container",
+            "table",
+            "table-caption",
+            "table-cell",
+            "table-column",
+            "table-column-group",
+            "table-footer-group",
+            "table-header-group",
+            "table-row",
+            "table-row-group",
+            "-webkit-box",
+            "-webkit-inline-box",
+        ]);
+    }
+}
+
 /// A specified value for the `vertical-align` property.
 pub type VerticalAlign = GenericVerticalAlign<LengthPercentage>;
 
diff --git a/components/style/values/specified/grid.rs b/components/style/values/specified/grid.rs
index 3e7f8f72a003..b75e97aca99c 100644
--- a/components/style/values/specified/grid.rs
+++ b/components/style/values/specified/grid.rs
@@ -6,10 +6,9 @@
 //! [grids](https://drafts.csswg.org/css-grid/)
 
 use crate::parser::{Parse, ParserContext};
-use crate::values::computed::{self, Context, ToComputedValue};
-use crate::values::generics::grid::{GridTemplateComponent, RepeatCount, TrackBreadth};
-use crate::values::generics::grid::{LineNameList, TrackRepeat, TrackSize};
-use crate::values::generics::grid::{TrackList, TrackListType, TrackListValue};
+use crate::values::generics::grid::{GridTemplateComponent, ImplicitGridTracks, RepeatCount};
+use crate::values::generics::grid::{LineNameList, TrackBreadth, TrackRepeat, TrackSize};
+use crate::values::generics::grid::{TrackList, TrackListValue};
 use crate::values::specified::{Integer, LengthPercentage};
 use crate::values::{CSSFloat, CustomIdent};
 use cssparser::{ParseError as CssParseError, Parser, Token};
@@ -96,12 +95,27 @@ impl Parse for TrackSize<LengthPercentage> {
     }
 }
 
+impl Parse for ImplicitGridTracks<TrackSize<LengthPercentage>> {
+    fn parse<'i, 't>(
+        context: &ParserContext,
+        input: &mut Parser<'i, 't>,
+    ) -> Result<Self, ParseError<'i>> {
+        use style_traits::{Separator, Space};
+        let track_sizes = Space::parse(input, |i| TrackSize::parse(context, i))?;
+        if track_sizes.len() == 1 && track_sizes[0].is_auto() {
+            //`auto`, which is the initial value, is always represented by an empty slice.
+            return Ok(Default::default());
+        }
+        return Ok(ImplicitGridTracks(track_sizes.into()));
+    }
+}
+
 /// Parse the grid line names into a vector of owned strings.
 ///
 /// <https://drafts.csswg.org/css-grid/#typedef-line-names>
 pub fn parse_line_names<'i, 't>(
     input: &mut Parser<'i, 't>,
-) -> Result<Box<[CustomIdent]>, ParseError<'i>> {
+) -> Result<crate::OwnedSlice<CustomIdent>, ParseError<'i>> {
     input.expect_square_bracket_block()?;
     input.parse_nested_block(|input| {
         let mut values = vec![];
@@ -112,7 +126,7 @@ pub fn parse_line_names<'i, 't>(
             values.push(ident);
         }
 
-        Ok(values.into_boxed_slice())
+        Ok(values.into())
     })
 }
 
@@ -155,9 +169,7 @@ impl TrackRepeat<LengthPercentage, Integer> {
                     let mut current_names;
 
                     loop {
-                        current_names = input
-                            .try(parse_line_names)
-                            .unwrap_or(vec![].into_boxed_slice());
+                        current_names = input.try(parse_line_names).unwrap_or_default();
                         if let Ok(track_size) = input.try(|i| TrackSize::parse(context, i)) {
                             if !track_size.is_fixed() {
                                 if is_auto {
@@ -180,11 +192,7 @@ impl TrackRepeat<LengthPercentage, Integer> {
                                 // one `TrackSize`. But in current version of the spec, this is deprecated
                                 // but we are adding this for gecko parity. We should remove this when
                                 // gecko implements new spec.
-                                names.push(
-                                    input
-                                        .try(parse_line_names)
-                                        .unwrap_or(vec![].into_boxed_slice()),
-                                );
+                                names.push(input.try(parse_line_names).unwrap_or_default());
                                 break;
                             }
                         } else {
@@ -201,9 +209,9 @@ impl TrackRepeat<LengthPercentage, Integer> {
                     }
 
                     let repeat = TrackRepeat {
-                        count: count,
-                        track_sizes: values,
-                        line_names: names.into_boxed_slice(),
+                        count,
+                        track_sizes: values.into(),
+                        line_names: names.into(),
                     };
 
                     Ok((repeat, repeat_type))
@@ -221,47 +229,31 @@ impl Parse for TrackList<LengthPercentage, Integer> {
         let mut names = vec![];
         let mut values = vec![];
 
-        // assume it's the simplest case.
-        let mut list_type = TrackListType::Explicit;
-        // holds <auto-repeat> value. It can only be only one in a TrackList.
-        let mut auto_repeat = None;
-        // if there is any <auto-repeat> the list will be of type TrackListType::Auto(idx)
-        // where idx points to the position of the <auto-repeat> in the track list. If there
-        // is any repeat before <auto-repeat>, we need to take the number of repetitions into
-        // account to set the position of <auto-repeat> so it remains the same while computing
-        // values.
-        let mut auto_offset = 0;
+        // Whether we've parsed an `<auto-repeat>` value.
+        let mut auto_repeat_index = None;
         // assume that everything is <fixed-size>. This flag is useful when we encounter <auto-repeat>
-        let mut atleast_one_not_fixed = false;
+        let mut at_least_one_not_fixed = false;
         loop {
-            current_names.extend_from_slice(
-                &mut input
-                    .try(parse_line_names)
-                    .unwrap_or(vec![].into_boxed_slice()),
-            );
+            current_names.extend_from_slice(&mut input.try(parse_line_names).unwrap_or_default());
             if let Ok(track_size) = input.try(|i| TrackSize::parse(context, i)) {
                 if !track_size.is_fixed() {
-                    atleast_one_not_fixed = true;
-                    if auto_repeat.is_some() {
+                    at_least_one_not_fixed = true;
+                    if auto_repeat_index.is_some() {
                         // <auto-track-list> only accepts <fixed-size> and <fixed-repeat>
                         return Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError));
                     }
                 }
 
                 let vec = mem::replace(&mut current_names, vec![]);
-                names.push(vec.into_boxed_slice());
+                names.push(vec.into());
                 values.push(TrackListValue::TrackSize(track_size));
             } else if let Ok((repeat, type_)) =
                 input.try(|i| TrackRepeat::parse_with_repeat_type(context, i))
             {
-                if list_type == TrackListType::Explicit {
-                    list_type = TrackListType::Normal; // <explicit-track-list> doesn't contain repeat()
-                }
-
                 match type_ {
                     RepeatType::Normal => {
-                        atleast_one_not_fixed = true;
-                        if auto_repeat.is_some() {
+                        at_least_one_not_fixed = true;
+                        if auto_repeat_index.is_some() {
                             // only <fixed-repeat>
                             return Err(
                                 input.new_custom_error(StyleParseErrorKind::UnspecifiedError)
@@ -269,137 +261,42 @@ impl Parse for TrackList<LengthPercentage, Integer> {
                         }
                     },
                     RepeatType::Auto => {
-                        if auto_repeat.is_some() || atleast_one_not_fixed {
+                        if auto_repeat_index.is_some() || at_least_one_not_fixed {
                             // We've either seen <auto-repeat> earlier, or there's at least one non-fixed value
                             return Err(
                                 input.new_custom_error(StyleParseErrorKind::UnspecifiedError)
                             );
                         }
-
-                        list_type = TrackListType::Auto(values.len() as u16 + auto_offset);
-                        auto_repeat = Some(repeat);
-                        let vec = mem::replace(&mut current_names, vec![]);
-                        names.push(vec.into_boxed_slice());
-                        continue;
+                        auto_repeat_index = Some(values.len());
                     },
-                    RepeatType::Fixed => (),
+                    RepeatType::Fixed => {},
                 }
 
                 let vec = mem::replace(&mut current_names, vec![]);
-                names.push(vec.into_boxed_slice());
-                if let RepeatCount::Number(num) = repeat.count {
-                    auto_offset += (num.value() - 1) as u16;
-                }
+                names.push(vec.into());
                 values.push(TrackListValue::TrackRepeat(repeat));
             } else {
-                if values.is_empty() && auto_repeat.is_none() {
+                if values.is_empty() && auto_repeat_index.is_none() {
                     return Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError));
                 }
 
-                names.push(current_names.into_boxed_slice());
+                names.push(current_names.into());
                 break;
             }
         }
 
         Ok(TrackList {
-            list_type: list_type,
-            values: values,
-            line_names: names.into_boxed_slice(),
-            auto_repeat: auto_repeat,
+            auto_repeat_index: auto_repeat_index.unwrap_or(std::usize::MAX),
+            values: values.into(),
+            line_names: names.into(),
         })
     }
 }
 
-impl ToComputedValue for TrackList<LengthPercentage, Integer> {
-    type ComputedValue = TrackList<computed::LengthPercentage, computed::Integer>;
-
-    #[inline]
-    fn to_computed_value(&self, context: &Context) -> Self::ComputedValue {
-        // Merge the line names while computing values. The resulting values will
-        // all be bunch of `<track-size>` and one <auto-repeat>.
-        //
-        // For example,
-        // `[a b] 100px [c d] repeat(1, 30px [g]) [h]` will be merged as `[a b] 100px [c d] 30px [g h]`
-        //  whereas, `[a b] repeat(2, [c] 50px [d]) [e f] repeat(auto-fill, [g] 12px) 10px [h]` will be merged as
-        // `[a b c] 50px [d c] 50px [d e f] repeat(auto-fill, [g] 12px) 10px [h]`, with the `<auto-repeat>` value
-        // set in the `auto_repeat` field, and the `idx` in TrackListType::Auto pointing to the values after
-        // `<auto-repeat>` (in this case, `10px [h]`).
-        let mut prev_names = vec![];
-        let mut line_names = Vec::with_capacity(self.line_names.len() + 1);
-        let mut values = Vec::with_capacity(self.values.len() + 1);
-        for (pos, names) in self.line_names.iter().enumerate() {
-            prev_names.extend_from_slice(&names);
-            if pos >= self.values.len() {
-                let vec = mem::replace(&mut prev_names, vec![]);
-                line_names.push(vec.into_boxed_slice());
-                continue;
-            }
-
-            match self.values[pos] {
-                TrackListValue::TrackSize(ref size) => {
-                    let vec = mem::replace(&mut prev_names, vec![]);
-                    line_names.push(vec.into_boxed_slice());
-                    values.push(TrackListValue::TrackSize(size.to_computed_value(context)));
-                },
-                TrackListValue::TrackRepeat(ref repeat) => {
-                    // If the repeat count is numeric, we expand and merge the values.
-                    let mut repeat = repeat.expand();
-                    let mut repeat_names_iter = repeat.line_names.iter();
-                    for (size, repeat_names) in
-                        repeat.track_sizes.drain(..).zip(&mut repeat_names_iter)
-                    {
-                        prev_names.extend_from_slice(&repeat_names);
-                        let vec = mem::replace(&mut prev_names, vec![]);
-                        line_names.push(vec.into_boxed_slice());
-                        values.push(TrackListValue::TrackSize(size.to_computed_value(context)));
-                    }
-
-                    if let Some(names) = repeat_names_iter.next() {
-                        prev_names.extend_from_slice(&names);
-                    }
-                },
-            }
-        }
-
-        TrackList {
-            list_type: self.list_type.to_computed_value(context),
-            values: values,
-            line_names: line_names.into_boxed_slice(),
-            auto_repeat: self
-                .auto_repeat
-                .clone()
-                .map(|repeat| repeat.to_computed_value(context)),
-        }
-    }
-
-    #[inline]
-    fn from_computed_value(computed: &Self::ComputedValue) -> Self {
-        let mut values = Vec::with_capacity(computed.values.len() + 1);
-        for value in computed
-            .values
-            .iter()
-            .map(ToComputedValue::from_computed_value)
-        {
-            values.push(value);
-        }
-
-        TrackList {
-            list_type: computed.list_type,
-            values: values,
-            line_names: computed.line_names.clone(),
-            auto_repeat: computed
-                .auto_repeat
-                .clone()
-                .map(|ref repeat| TrackRepeat::from_computed_value(repeat)),
-        }
-    }
-}
-
 #[cfg(feature = "gecko")]
 #[inline]
 fn allow_grid_template_subgrids() -> bool {
-    use crate::gecko_bindings::structs::mozilla;
-    unsafe { mozilla::StaticPrefs::sVarCache_layout_css_grid_template_subgrid_value_enabled }
+    static_prefs::pref!("layout.css.grid-template-subgrid-value.enabled")
 }
 
 #[cfg(feature = "servo")]
@@ -409,7 +306,6 @@ fn allow_grid_template_subgrids() -> bool {
 }
 
 impl Parse for GridTemplateComponent<LengthPercentage, Integer> {
-    // FIXME: Derive Parse (probably with None_)
     fn parse<'i, 't>(
         context: &ParserContext,
         input: &mut Parser<'i, 't>,
@@ -430,10 +326,11 @@ impl GridTemplateComponent<LengthPercentage, Integer> {
     ) -> Result<Self, ParseError<'i>> {
         if allow_grid_template_subgrids() {
             if let Ok(t) = input.try(|i| LineNameList::parse(context, i)) {
-                return Ok(GridTemplateComponent::Subgrid(t));
+                return Ok(GridTemplateComponent::Subgrid(Box::new(t)));
             }
         }
 
-        TrackList::parse(context, input).map(GridTemplateComponent::TrackList)
+        let track_list = TrackList::parse(context, input)?;
+        Ok(GridTemplateComponent::TrackList(Box::new(track_list)))
     }
 }
diff --git a/components/style/values/specified/mod.rs b/components/style/values/specified/mod.rs
index f33a191c2773..16897043da95 100644
--- a/components/style/values/specified/mod.rs
+++ b/components/style/values/specified/mod.rs
@@ -8,6 +8,7 @@
 
 use super::computed::transform::DirectionVector;
 use super::computed::{Context, ToComputedValue};
+use super::generics::grid::ImplicitGridTracks as GenericImplicitGridTracks;
 use super::generics::grid::{GridLine as GenericGridLine, TrackBreadth as GenericTrackBreadth};
 use super::generics::grid::{TrackList as GenericTrackList, TrackSize as GenericTrackSize};
 use super::generics::transform::IsParallelTo;
@@ -69,7 +70,7 @@ pub use self::list::Quotes;
 pub use self::motion::{OffsetPath, OffsetRotate};
 pub use self::outline::OutlineStyle;
 pub use self::percentage::Percentage;
-pub use self::position::{GridAutoFlow, GridTemplateAreas, Position};
+pub use self::position::{GridAutoFlow, GridTemplateAreas, Position, PositionOrAuto};
 pub use self::position::{PositionComponent, ZIndex};
 pub use self::rect::NonNegativeLengthOrNumberRect;
 pub use self::resolution::Resolution;
@@ -81,7 +82,7 @@ pub use self::table::XSpan;
 pub use self::text::{InitialLetter, LetterSpacing, LineBreak, LineHeight, TextAlign};
 pub use self::text::{OverflowWrap, TextEmphasisPosition, TextEmphasisStyle, WordBreak};
 pub use self::text::{TextAlignKeyword, TextDecorationLine, TextOverflow, WordSpacing};
-pub use self::text::{TextDecorationSkipInk, TextTransform};
+pub use self::text::{TextDecorationLength, TextDecorationSkipInk, TextTransform};
 pub use self::time::Time;
 pub use self::transform::{Rotate, Scale, Transform};
 pub use self::transform::{TransformOrigin, TransformStyle, Translate};
@@ -626,6 +627,9 @@ pub type TrackBreadth = GenericTrackBreadth<LengthPercentage>;
 /// The specified value of a grid `<track-size>`
 pub type TrackSize = GenericTrackSize<LengthPercentage>;
 
+/// The specified value of a grid `<track-size>+`
+pub type ImplicitGridTracks = GenericImplicitGridTracks<TrackSize>;
+
 /// The specified value of a grid `<track-list>`
 /// (could also be `<auto-track-list>` or `<explicit-track-list>`)
 pub type TrackList = GenericTrackList<LengthPercentage, Integer>;
diff --git a/components/style/values/specified/position.rs b/components/style/values/specified/position.rs
index 4e6a71ec2cad..ce3bab1047be 100644
--- a/components/style/values/specified/position.rs
+++ b/components/style/values/specified/position.rs
@@ -13,6 +13,7 @@ use crate::str::HTML_SPACE_CHARACTERS;
 use crate::values::computed::LengthPercentage as ComputedLengthPercentage;
 use crate::values::computed::{Context, Percentage, ToComputedValue};
 use crate::values::generics::position::Position as GenericPosition;
+use crate::values::generics::position::PositionOrAuto as GenericPositionOrAuto;
 use crate::values::generics::position::ZIndex as GenericZIndex;
 use crate::values::specified::{AllowQuirks, Integer, LengthPercentage};
 use crate::Atom;
@@ -26,6 +27,9 @@ use style_traits::{CssWriter, ParseError, StyleParseErrorKind, ToCss};
 /// The specified value of a CSS `<position>`
 pub type Position = GenericPosition<HorizontalPosition, VerticalPosition>;
 
+/// The specified value of an `auto | <position>`.
+pub type PositionOrAuto = GenericPositionOrAuto<Position>;
+
 /// The specified value of a horizontal position.
 pub type HorizontalPosition = PositionComponent<HorizontalPositionKeyword>;
 
diff --git a/components/style/values/specified/svg.rs b/components/style/values/specified/svg.rs
index 9279707935fe..4858fbaec6b9 100644
--- a/components/style/values/specified/svg.rs
+++ b/components/style/values/specified/svg.rs
@@ -32,8 +32,7 @@ pub type SVGStrokeDashArray = generic::SVGStrokeDashArray<NonNegativeLengthPerce
 /// Whether the `context-value` value is enabled.
 #[cfg(feature = "gecko")]
 pub fn is_context_value_enabled() -> bool {
-    use crate::gecko_bindings::structs::mozilla;
-    unsafe { mozilla::StaticPrefs::sVarCache_gfx_font_rendering_opentype_svg_enabled }
+    static_prefs::pref!("gfx.font_rendering.opentype_svg.enabled")
 }
 
 /// Whether the `context-value` value is enabled.
diff --git a/components/style/values/specified/svg_path.rs b/components/style/values/specified/svg_path.rs
index e5282e0a1646..4f49029b51ea 100644
--- a/components/style/values/specified/svg_path.rs
+++ b/components/style/values/specified/svg_path.rs
@@ -625,40 +625,26 @@ impl<'a> PathParser<'a> {
                 break;
             }
 
-            match self.chars.next() {
-                Some(command) => {
-                    let abs = if command.is_ascii_uppercase() {
-                        IsAbsolute::Yes
-                    } else {
-                        IsAbsolute::No
-                    };
-                    macro_rules! parse_command {
-                        ( $($($p:pat)|+ => $parse_func:ident,)* ) => {
-                            match command {
-                                $(
-                                    $($p)|+ => {
-                                        skip_wsp(&mut self.chars);
-                                        self.$parse_func(abs)?;
-                                    },
-                                )*
-                                _ => return Err(()),
-                            }
-                        }
-                    }
-                    parse_command!(
-                        b'Z' | b'z' => parse_closepath,
-                        b'L' | b'l' => parse_lineto,
-                        b'H' | b'h' => parse_h_lineto,
-                        b'V' | b'v' => parse_v_lineto,
-                        b'C' | b'c' => parse_curveto,
-                        b'S' | b's' => parse_smooth_curveto,
-                        b'Q' | b'q' => parse_quadratic_bezier_curveto,
-                        b'T' | b't' => parse_smooth_quadratic_bezier_curveto,
-                        b'A' | b'a' => parse_elliptical_arc,
-                    );
-                },
-                _ => break, // no more commands.
-            }
+            let command = self.chars.next().unwrap();
+            let abs = if command.is_ascii_uppercase() {
+                IsAbsolute::Yes
+            } else {
+                IsAbsolute::No
+            };
+
+            skip_wsp(&mut self.chars);
+            match command {
+                b'Z' | b'z' => self.parse_closepath(),
+                b'L' | b'l' => self.parse_lineto(abs),
+                b'H' | b'h' => self.parse_h_lineto(abs),
+                b'V' | b'v' => self.parse_v_lineto(abs),
+                b'C' | b'c' => self.parse_curveto(abs),
+                b'S' | b's' => self.parse_smooth_curveto(abs),
+                b'Q' | b'q' => self.parse_quadratic_bezier_curveto(abs),
+                b'T' | b't' => self.parse_smooth_quadratic_bezier_curveto(abs),
+                b'A' | b'a' => self.parse_elliptical_arc(abs),
+                _ => return Err(()),
+            }?;
         }
         Ok(())
     }
@@ -692,7 +678,7 @@ impl<'a> PathParser<'a> {
     }
 
     /// Parse "closepath" command.
-    fn parse_closepath(&mut self, _absolute: IsAbsolute) -> Result<(), ()> {
+    fn parse_closepath(&mut self) -> Result<(), ()> {
         self.path.push(PathCommand::ClosePath);
         Ok(())
     }
diff --git a/components/style/values/specified/text.rs b/components/style/values/specified/text.rs
index c66e93803f6e..1686b9f424dc 100644
--- a/components/style/values/specified/text.rs
+++ b/components/style/values/specified/text.rs
@@ -7,13 +7,12 @@
 use crate::parser::{Parse, ParserContext};
 use crate::properties::longhands::writing_mode::computed_value::T as SpecifiedWritingMode;
 use crate::values::computed::text::LineHeight as ComputedLineHeight;
-use crate::values::computed::text::TextEmphasisKeywordValue as ComputedTextEmphasisKeywordValue;
 use crate::values::computed::text::TextEmphasisStyle as ComputedTextEmphasisStyle;
 use crate::values::computed::text::TextOverflow as ComputedTextOverflow;
 use crate::values::computed::{Context, ToComputedValue};
 use crate::values::generics::text::InitialLetter as GenericInitialLetter;
 use crate::values::generics::text::LineHeight as GenericLineHeight;
-use crate::values::generics::text::Spacing;
+use crate::values::generics::text::{GenericTextDecorationLength, Spacing};
 use crate::values::specified::length::NonNegativeLengthPercentage;
 use crate::values::specified::length::{FontRelativeLength, Length};
 use crate::values::specified::length::{LengthPercentage, NoCalcLength};
@@ -645,48 +644,34 @@ impl ToComputedValue for TextAlign {
     }
 }
 
+fn fill_mode_is_default_and_shape_exists(
+    fill: &TextEmphasisFillMode,
+    shape: &Option<TextEmphasisShapeKeyword>,
+) -> bool {
+    shape.is_some() && fill.is_filled()
+}
+
 /// Specified value of text-emphasis-style property.
+///
+/// https://drafts.csswg.org/css-text-decor/#propdef-text-emphasis-style
 #[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
+#[allow(missing_docs)]
 pub enum TextEmphasisStyle {
-    /// <fill> <shape>
-    Keyword(TextEmphasisKeywordValue),
+    /// [ <fill> || <shape> ]
+    Keyword {
+        #[css(contextual_skip_if = "fill_mode_is_default_and_shape_exists")]
+        fill: TextEmphasisFillMode,
+        shape: Option<TextEmphasisShapeKeyword>,
+    },
     /// `none`
     None,
-    /// String (will be used only first grapheme cluster) for the text-emphasis-style property
-    String(String),
-}
-
-/// Keyword value for the text-emphasis-style property
-#[derive(Clone, Debug, MallocSizeOf, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
-pub enum TextEmphasisKeywordValue {
-    /// <fill>
-    Fill(TextEmphasisFillMode),
-    /// <shape>
-    Shape(TextEmphasisShapeKeyword),
-    /// <fill> <shape>
-    FillAndShape(TextEmphasisFillMode, TextEmphasisShapeKeyword),
-}
-
-impl TextEmphasisKeywordValue {
-    fn fill(&self) -> Option<TextEmphasisFillMode> {
-        match *self {
-            TextEmphasisKeywordValue::Fill(fill) |
-            TextEmphasisKeywordValue::FillAndShape(fill, _) => Some(fill),
-            _ => None,
-        }
-    }
-
-    fn shape(&self) -> Option<TextEmphasisShapeKeyword> {
-        match *self {
-            TextEmphasisKeywordValue::Shape(shape) |
-            TextEmphasisKeywordValue::FillAndShape(_, shape) => Some(shape),
-            _ => None,
-        }
-    }
+    /// `<string>` (of which only the first grapheme cluster will be used).
+    String(crate::OwnedStr),
 }
 
 /// Fill mode for the text-emphasis-style property
 #[derive(Clone, Copy, Debug, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem)]
+#[repr(u8)]
 pub enum TextEmphasisFillMode {
     /// `filled`
     Filled,
@@ -694,10 +679,19 @@ pub enum TextEmphasisFillMode {
     Open,
 }
 
+impl TextEmphasisFillMode {
+    /// Whether the value is `filled`.
+    #[inline]
+    pub fn is_filled(&self) -> bool {
+        matches!(*self, TextEmphasisFillMode::Filled)
+    }
+}
+
 /// Shape keyword for the text-emphasis-style property
 #[derive(
     Clone, Copy, Debug, Eq, MallocSizeOf, Parse, PartialEq, SpecifiedValueInfo, ToCss, ToShmem,
 )]
+#[repr(u8)]
 pub enum TextEmphasisShapeKeyword {
     /// `dot`
     Dot,
@@ -711,77 +705,39 @@ pub enum TextEmphasisShapeKeyword {
     Sesame,
 }
 
-impl TextEmphasisShapeKeyword {
-    /// converts fill mode to a unicode char
-    pub fn char(&self, fill: TextEmphasisFillMode) -> &str {
-        let fill = fill == TextEmphasisFillMode::Filled;
-        match *self {
-            TextEmphasisShapeKeyword::Dot => {
-                if fill {
-                    "\u{2022}"
-                } else {
-                    "\u{25e6}"
-                }
-            },
-            TextEmphasisShapeKeyword::Circle => {
-                if fill {
-                    "\u{25cf}"
-                } else {
-                    "\u{25cb}"
-                }
-            },
-            TextEmphasisShapeKeyword::DoubleCircle => {
-                if fill {
-                    "\u{25c9}"
-                } else {
-                    "\u{25ce}"
-                }
-            },
-            TextEmphasisShapeKeyword::Triangle => {
-                if fill {
-                    "\u{25b2}"
-                } else {
-                    "\u{25b3}"
-                }
-            },
-            TextEmphasisShapeKeyword::Sesame => {
-                if fill {
-                    "\u{fe45}"
-                } else {
-                    "\u{fe46}"
-                }
-            },
-        }
-    }
-}
-
 impl ToComputedValue for TextEmphasisStyle {
     type ComputedValue = ComputedTextEmphasisStyle;
 
     #[inline]
     fn to_computed_value(&self, context: &Context) -> Self::ComputedValue {
         match *self {
-            TextEmphasisStyle::Keyword(ref keyword) => {
-                // FIXME(emilio): This should set the rule_cache_conditions
-                // properly.
-                let default_shape = if context.style().get_inherited_box().clone_writing_mode() ==
-                    SpecifiedWritingMode::HorizontalTb
-                {
-                    TextEmphasisShapeKeyword::Circle
-                } else {
-                    TextEmphasisShapeKeyword::Sesame
-                };
-                ComputedTextEmphasisStyle::Keyword(ComputedTextEmphasisKeywordValue {
-                    fill: keyword.fill().unwrap_or(TextEmphasisFillMode::Filled),
-                    shape: keyword.shape().unwrap_or(default_shape),
-                })
+            TextEmphasisStyle::Keyword { fill, shape } => {
+                let shape = shape.unwrap_or_else(|| {
+                    // FIXME(emilio, bug 1572958): This should set the
+                    // rule_cache_conditions properly.
+                    //
+                    // Also should probably use WritingMode::is_vertical rather
+                    // than the computed value of the `writing-mode` property.
+                    if context.style().get_inherited_box().clone_writing_mode() ==
+                        SpecifiedWritingMode::HorizontalTb
+                    {
+                        TextEmphasisShapeKeyword::Circle
+                    } else {
+                        TextEmphasisShapeKeyword::Sesame
+                    }
+                });
+                ComputedTextEmphasisStyle::Keyword { fill, shape }
             },
             TextEmphasisStyle::None => ComputedTextEmphasisStyle::None,
             TextEmphasisStyle::String(ref s) => {
                 // Passing `true` to iterate over extended grapheme clusters, following
                 // recommendation at http://www.unicode.org/reports/tr29/#Grapheme_Cluster_Boundaries
-                let string = s.graphemes(true).next().unwrap_or("").to_string();
-                ComputedTextEmphasisStyle::String(string)
+                //
+                // FIXME(emilio): Doing this at computed value time seems wrong.
+                // The spec doesn't say that this should be a computed-value
+                // time operation. This is observable from getComputedStyle().
+                let s = s.graphemes(true).next().unwrap_or("").to_string();
+                ComputedTextEmphasisStyle::String(s.into())
             },
         }
     }
@@ -789,9 +745,10 @@ impl ToComputedValue for TextEmphasisStyle {
     #[inline]
     fn from_computed_value(computed: &Self::ComputedValue) -> Self {
         match *computed {
-            ComputedTextEmphasisStyle::Keyword(ref keyword) => TextEmphasisStyle::Keyword(
-                TextEmphasisKeywordValue::FillAndShape(keyword.fill, keyword.shape),
-            ),
+            ComputedTextEmphasisStyle::Keyword { fill, shape } => TextEmphasisStyle::Keyword {
+                fill,
+                shape: Some(shape),
+            },
             ComputedTextEmphasisStyle::None => TextEmphasisStyle::None,
             ComputedTextEmphasisStyle::String(ref string) => {
                 TextEmphasisStyle::String(string.clone())
@@ -814,7 +771,7 @@ impl Parse for TextEmphasisStyle {
 
         if let Ok(s) = input.try(|i| i.expect_string().map(|s| s.as_ref().to_owned())) {
             // Handle <string>
-            return Ok(TextEmphasisStyle::String(s));
+            return Ok(TextEmphasisStyle::String(s.into()));
         }
 
         // Handle a pair of keywords
@@ -824,14 +781,17 @@ impl Parse for TextEmphasisStyle {
             shape = input.try(TextEmphasisShapeKeyword::parse).ok();
         }
 
-        // At least one of shape or fill must be handled
-        let keyword_value = match (fill, shape) {
-            (Some(fill), Some(shape)) => TextEmphasisKeywordValue::FillAndShape(fill, shape),
-            (Some(fill), None) => TextEmphasisKeywordValue::Fill(fill),
-            (None, Some(shape)) => TextEmphasisKeywordValue::Shape(shape),
-            _ => return Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError)),
-        };
-        Ok(TextEmphasisStyle::Keyword(keyword_value))
+        if shape.is_none() && fill.is_none() {
+            return Err(input.new_custom_error(StyleParseErrorKind::UnspecifiedError));
+        }
+
+        // If a shape keyword is specified but neither filled nor open is
+        // specified, filled is assumed.
+        let fill = fill.unwrap_or(TextEmphasisFillMode::Filled);
+
+        // We cannot do the same because the default `<shape>` depends on the
+        // computed writing-mode.
+        Ok(TextEmphasisStyle::Keyword { fill, shape })
     }
 }
 
@@ -1079,3 +1039,20 @@ pub enum TextDecorationSkipInk {
     Auto,
     None,
 }
+
+/// Implements type for `text-underline-offset` and `text-decoration-thickness` properties
+pub type TextDecorationLength = GenericTextDecorationLength<Length>;
+
+impl TextDecorationLength {
+    /// `Auto` value.
+    #[inline]
+    pub fn auto() -> Self {
+        GenericTextDecorationLength::Auto
+    }
+
+    /// Whether this is the `Auto` value.
+    #[inline]
+    pub fn is_auto(&self) -> bool {
+        matches!(*self, GenericTextDecorationLength::Auto)
+    }
+}
diff --git a/components/style/values/specified/ui.rs b/components/style/values/specified/ui.rs
index 0cc20d960c6e..46272b2ae851 100644
--- a/components/style/values/specified/ui.rs
+++ b/components/style/values/specified/ui.rs
@@ -199,7 +199,9 @@ pub enum CursorKind {
     Move,
     NoDrop,
     NotAllowed,
+    #[parse(aliases = "-moz-grab")]
     Grab,
+    #[parse(aliases = "-moz-grabbing")]
     Grabbing,
     EResize,
     NResize,
@@ -216,15 +218,9 @@ pub enum CursorKind {
     ColResize,
     RowResize,
     AllScroll,
+    #[parse(aliases = "-moz-zoom-in")]
     ZoomIn,
+    #[parse(aliases = "-moz-zoom-out")]
     ZoomOut,
     Auto,
-    #[cfg(feature = "gecko")]
-    MozGrab,
-    #[cfg(feature = "gecko")]
-    MozGrabbing,
-    #[cfg(feature = "gecko")]
-    MozZoomIn,
-    #[cfg(feature = "gecko")]
-    MozZoomOut,
 }
diff --git a/components/style_traits/specified_value_info.rs b/components/style_traits/specified_value_info.rs
index 39740bc72621..1dd368d36e9c 100644
--- a/components/style_traits/specified_value_info.rs
+++ b/components/style_traits/specified_value_info.rs
@@ -82,6 +82,7 @@ impl SpecifiedValueInfo for i32 {}
 impl SpecifiedValueInfo for u8 {}
 impl SpecifiedValueInfo for u16 {}
 impl SpecifiedValueInfo for u32 {}
+impl SpecifiedValueInfo for usize {}
 impl SpecifiedValueInfo for str {}
 impl SpecifiedValueInfo for String {}
 impl SpecifiedValueInfo for crate::owned_str::OwnedStr {}
diff --git a/servo-tidy.toml b/servo-tidy.toml
index 42a253b1aa7c..cedd07f27116 100644
--- a/servo-tidy.toml
+++ b/servo-tidy.toml
@@ -56,6 +56,7 @@ files = [
   "./components/net/tests/parsable_mime/text",
   # Mako does not lend itself easily to splitting long lines
   "./components/style/properties/helpers/animated_properties.mako.rs",
+  "./components/style/properties/shorthands/text.mako.rs",
   # Long regexes are long.
   "./components/style/gecko/regen_atoms.py",
   # Helper macro where actually a pseudo-element per line makes sense.
diff --git a/tests/wpt/metadata/css/css-fonts/font-weight-xxx-large.html.ini b/tests/wpt/metadata/css/css-fonts/font-weight-xxx-large.html.ini
deleted file mode 100644
index 86fcb0cf546a..000000000000
--- a/tests/wpt/metadata/css/css-fonts/font-weight-xxx-large.html.ini
+++ /dev/null
@@ -1,2 +0,0 @@
-[font-weight-xxx-large.html]
-  expected: FAIL
diff --git a/tests/wpt/metadata/css/css-fonts/parsing/font-size-valid.html.ini b/tests/wpt/metadata/css/css-fonts/parsing/font-size-valid.html.ini
deleted file mode 100644
index 4b1533148fc2..000000000000
--- a/tests/wpt/metadata/css/css-fonts/parsing/font-size-valid.html.ini
+++ /dev/null
@@ -1,4 +0,0 @@
-[font-size-valid.html]
-  [e.style['font-size'\] = "xxx-large" should set the property value]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata/html/rendering/widgets/button-layout/display-other.html.ini b/tests/wpt/metadata/html/rendering/widgets/button-layout/display-other.html.ini
index 95591d2929cb..e8cfab844933 100644
--- a/tests/wpt/metadata/html/rendering/widgets/button-layout/display-other.html.ini
+++ b/tests/wpt/metadata/html/rendering/widgets/button-layout/display-other.html.ini
@@ -44,9 +44,6 @@
   [display: table-row-group]
     expected: FAIL
 
-  [display: flow]
-    expected: FAIL
-
   [display: table-column-group]
     expected: FAIL