Add custom scrollbar styles.

src/stylesheets/components/_panel.scss

@@ -44,4 +44,14 @@
       margin-bottom: $space-min;
     }
   }
+
+  ::-webkit {
+    &-track {
+      background: $panel-bg;
+    }
+
+    &-thumb {
+      border-color: $panel-bg;
+    }
+  }
 }

src/stylesheets/components/_sidebar.scss

@@ -198,4 +198,16 @@
   .icon-spin {
     animation: spin 1.2s linear infinite;
   }
+
+  ::-webkit {
+    &-scrollbar {
+      &-track {
+        background: $sidebar-bg;
+      }
+
+      &-thumb {
+        border-color: $sidebar-bg;
+      }
+    }
+  }
 }

src/stylesheets/partials/_scrollbar.scss

@@ -0,0 +1,31 @@
+//
+// Scrollbar
+// --------------------------------------------------
+
+::-webkit {
+  &-scrollbar {
+    width: 12px;
+    height: 12px;
+
+    &:vertical {
+      margin-right: 20px;
+    }
+
+    &-track {
+      background: $scrollbar-bg;
+    }
+
+    &-thumb {
+      background: $scrollbar-color;
+      border-radius: 6px;
+      border: 4px solid $scrollbar-bg;
+      background-clip: content-box;
+
+      &:vertical {
+        &:active {
+          border: 0;
+        }
+      }
+    }
+  }
+}

src/stylesheets/themes/_dark.scss

@@ -77,6 +77,10 @@ $stack-color:       $shade-7; // Ok
 $stack-bg:          $body-bg; // Ok
 $stack-focus-color: $brand-primary-light; // Ok
 
+// Scrollbar
+$scrollbar-bg: $body-bg; // Ok
+$scrollbar-color: $shade-5; // Ok
+
 
 // Components
 // --------------------------------------------------

src/stylesheets/themes/_light.scss

@@ -123,6 +123,10 @@ $stack-color:       $shade-5;
 $stack-bg:          $body-bg;
 $stack-focus-color: $shade-0;
 
+// Scrollbar
+$scrollbar-bg: $body-bg;
+$scrollbar-color: $shade-4;
+
 
 // Components
 // --------------------------------------------------

src/stylesheets/windows/_project.scss

@@ -66,4 +66,5 @@
   "../partials/tile",
   "../partials/sort-indicator",
   "../partials/debug",
-  "../partials/scroll-container";
+  "../partials/scroll-container",
+  "../partials/scrollbar";