diff --git a/third_party/site-shared/README.md b/third_party/site-shared/README.md
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index 0000000000..d410e33808
--- /dev/null
+++ b/third_party/site-shared/README.md
@@ -0,0 +1,7 @@
+# Content and infrastructure shared across Dart and Flutter websites.
+
+Vendoring resource files from:
+- https://github.com/dart-lang/site-shared/tree/main/pkgs/dash_design
+
+Vendored files can be updated by running:
+`./update-site-shared.sh`
diff --git a/third_party/site-shared/dash_design/LICENSE b/third_party/site-shared/dash_design/LICENSE
new file mode 100644
index 0000000000..b03a788683
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+++ b/third_party/site-shared/dash_design/LICENSE
@@ -0,0 +1,27 @@
+Copyright 2024, the Dart project authors.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are
+met:
+
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above
+      copyright notice, this list of conditions and the following
+      disclaimer in the documentation and/or other materials provided
+      with the distribution.
+    * Neither the name of Google LLC nor the names of its
+      contributors may be used to endorse or promote products derived
+      from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+"AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/third_party/site-shared/dash_design/lib/styles.scss b/third_party/site-shared/dash_design/lib/styles.scss
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index 0000000000..b575311200
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+++ b/third_party/site-shared/dash_design/lib/styles.scss
@@ -0,0 +1,33 @@
+// Copyright (c) 2024, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// styles.scss:
+///
+/// Incorporates all styles and CSS custom properties (variables)
+/// from the dash_design package.
+///
+/// Most variables are added at the `:root` (the `html` element),
+/// but dark mode variable overrides are added to the `body` element if
+/// the class `dark-theme` is added to it.
+
+@use 'styles/variables';
+
+$google-site: false !default;
+
+:root {
+  @include variables.typography;
+  @include variables.shared-colors;
+
+  @include variables.light-theme;
+
+  @if $google-site {
+    @include variables.google-overrides;
+  }
+}
+
+body {
+  &.dark-theme {
+    @include variables.dark-theme;
+  }
+}
diff --git a/third_party/site-shared/dash_design/lib/styles/variables.scss b/third_party/site-shared/dash_design/lib/styles/variables.scss
new file mode 100644
index 0000000000..96d082ddf0
--- /dev/null
+++ b/third_party/site-shared/dash_design/lib/styles/variables.scss
@@ -0,0 +1,52 @@
+// Copyright (c) 2024, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+/// styles/variables.scss:
+///
+/// Mixins that can be included to load CSS custom properties (variables)
+/// into any desired scope.
+
+/// Shared typography CSS variables.
+@mixin typography {
+  /// Used for body text and smaller UI elements, like labels.
+  --dash-default-fontFamily: 'Roboto', sans-serif;
+
+  /// Used for headlines, titles, and larger UI elements.
+  --dash-display-fontFamily: 'Roboto', sans-serif;
+
+  /// Used for monospace text, such as code blocks.
+  --dash-mono-fontFamily: 'Roboto Mono', 'Source Code Pro', 'Cascadia Mono', 'JetBrains Mono', monospace;
+
+  /// Used for icons, such as the magnifying glass for search.
+  --dash-symbol-fontFamily: 'Material Symbols', 'Material Symbols Outlined';
+}
+
+/// Color-related, theme-agnostic CSS variables.
+@mixin shared-colors {
+
+}
+
+/// Light-theme specific CSS variables.
+@mixin light-theme {
+  /// The default text color, used for body text.
+  --dash-surface-fgColor: #4a4a4a;
+}
+
+/// Dark-theme specific CSS variables.
+@mixin dark-theme {
+  --dash-surface-fgColor: #dcdcdc;
+}
+
+/// CSS variables that specify values that can only be used by Google sites,
+/// such as enabling the Google Sans font families.
+///
+/// These overrides should be included after all other variables are defined.
+@mixin google-overrides {
+  // Non-Google sites, such as self-hosted API docs,
+  // can't use Google Sans or Google Symbols.
+  --dash-default-fontFamily: 'Google Sans Text', 'Google Sans', 'Roboto', sans-serif;
+  --dash-display-fontFamily: 'Google Sans', 'Google Sans Text', 'Roboto', sans-serif;
+  --dash-mono-fontFamily: 'Google Sans Mono', 'Roboto Mono', 'Source Code Pro', 'Cascadia Mono', 'JetBrains Mono', monospace;
+  --dash-symbol-fontFamily: 'Google Symbols', 'Material Symbols', 'Material Symbols Outlined';
+}
diff --git a/third_party/site-shared/last-updated.txt b/third_party/site-shared/last-updated.txt
new file mode 100644
index 0000000000..128bd02dd5
--- /dev/null
+++ b/third_party/site-shared/last-updated.txt
@@ -0,0 +1,2 @@
+commit c30707803572c7c7c2fd3650d8c6e2a2e61731f4
+2024-11-06T15:44+01:00
diff --git a/third_party/site-shared/update-site-shared.sh b/third_party/site-shared/update-site-shared.sh
new file mode 100755
index 0000000000..4ceb999b92
--- /dev/null
+++ b/third_party/site-shared/update-site-shared.sh
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+#!/bin/bash
+set -e
+
+SCRIPT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+TEMP_DIR=$(mktemp -d)
+
+# Clone site-shared repository
+git clone https://github.com/dart-lang/site-shared "$TEMP_DIR"
+
+# Delete the previous version
+rm -rf "$SCRIPT_DIR/dash_design"
+
+# Copy css, js, png files to dash_design/
+mkdir "$SCRIPT_DIR/dash_design"
+cp -r "$TEMP_DIR"/pkgs/dash_design/lib/ "$SCRIPT_DIR/dash_design/"
+
+# Copy license
+cp "$TEMP_DIR/pkgs/dash_design/LICENSE" "$SCRIPT_DIR/dash_design/LICENSE"
+
+# Update the last updated file:
+cd "$TEMP_DIR"/pkgs/dash_design/ && git show --summary | grep commit | head -1 >"$SCRIPT_DIR/last-updated.txt"
+date -Iminutes >>"$SCRIPT_DIR/last-updated.txt"
+
+# Cleanup
+cd "$SCRIPT_DIR"
+rm -rf "$TEMP_DIR"