dart-lang · adil192 · Jun 27, 2025 · Jun 27, 2025 · Jun 27, 2025
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -4,6 +4,7 @@
 * Remove the deprecated `nodoc` option.
 * Remove the deprecated `include-external` option.
 * Refactor 404 error page to use div instead of p for search form.
+* Fix the flash of white while loading pages in dark mode in Firefox.
 
 ## 8.3.4
 * The URL for category pages now uses _category name_ instead of

diff --git a/lib/resources/docs.dart.js b/lib/resources/docs.dart.js
diff --git a/lib/resources/docs.dart.js.map b/lib/resources/docs.dart.js.map
diff --git a/lib/resources/styles.css b/lib/resources/styles.css
diff --git a/lib/src/generator/templates.aot_renderers_for_html.dart b/lib/src/generator/templates.aot_renderers_for_html.dart
@@ -2418,6 +2418,7 @@ String _deduplicated__head(TemplateDataBase context0) {
   <meta charset="utf-8">
   <meta http-equiv="X-UA-Compatible" content="IE=edge">
   <meta name="viewport" content="width=device-width, height=device-height, initial-scale=1, user-scalable=no">
+  <meta name="color-scheme" content="light dark">
   <meta name="description" content="''');
   buffer.writeEscaped(context0.metaDescription);
   buffer.write('''">
@@ -2476,7 +2477,7 @@ String _deduplicated__head(TemplateDataBase context0) {
   buffer.write(context0.htmlBase);
   buffer.write('''" data-using-base-href="''');
   buffer.write(context0.useBaseHref.toString());
-  buffer.write('''" class="light-theme">
+  buffer.write('''" class="light-theme loading-theme">
 <div id="overlay-under-drawer"></div>
 <header id="title">
   <span id="sidenav-left-toggle" class="material-symbols-outlined" role="button" tabindex="0">menu</span>

diff --git a/lib/templates/_head.html b/lib/templates/_head.html
@@ -4,6 +4,7 @@
   <meta charset="utf-8">
   <meta http-equiv="X-UA-Compatible" content="IE=edge">
   <meta name="viewport" content="width=device-width, height=device-height, initial-scale=1, user-scalable=no">
+  <meta name="color-scheme" content="light dark">
   <meta name="description" content="{{ metaDescription }}">
   <title>{{ title }}</title>
   {{ #relCanonicalPrefix }}
@@ -30,7 +31,7 @@
 </head>
 
 {{! We don't use <base href>, but we do lookup the htmlBase from javascript. }}
-<body data-base-href="{{{htmlBase}}}" data-using-base-href="{{{useBaseHref}}}" class="light-theme">
+<body data-base-href="{{{htmlBase}}}" data-using-base-href="{{{useBaseHref}}}" class="light-theme loading-theme">
 
 <div id="overlay-under-drawer"></div>
 

diff --git a/web/sig.txt b/web/sig.txt
@@ -1 +1 @@
-76460F3B17D947F654BCE4B231EBE30F
+8B61A9700A910E857DB14C88C8B399DC
diff --git a/web/styles/_theme.scss b/web/styles/_theme.scss
@@ -107,6 +107,17 @@
   }
 }
 
+.loading-theme {
+  // Until the light-mode or dark-mode class is applied to the body,
+  // this class tells the browser to use the system theme's lightness.
+  // This prevents a white flash while the page is loading.
+  color-scheme: light dark;
+  background: initial;
+  color: initial;
+  --main-bg-color: initial;
+  --main-header-color: initial;
+}
+
 #theme-button {
   // Reset button appearance.
   appearance: none;

diff --git a/web/theme.dart b/web/theme.dart
@@ -27,6 +27,8 @@ void init() {
 
       window.localStorage.setItem('colorTheme', 'false');
     }
+
+    bodyElement.classList.remove('loading-theme');
   }
 
   themeButton.addEventListener(
@@ -39,5 +41,8 @@ void init() {
 
   if (window.localStorage.getItem('colorTheme') case var colorTheme?) {
     switchThemes(colorTheme == 'true');
+  } else {
+    // Default to light mode.
+    switchThemes(false);
   }
 }
Original file line number	Diff line number	Diff line change
		@@ -1 +1 @@
		76460F3B17D947F654BCE4B231EBE30F
		8B61A9700A910E857DB14C88C8B399DC