Migrate stab elements style to CSS variables

Author: GuillaumeGomez

src/librustdoc/html/static/css/rustdoc.css

@@ -1062,6 +1062,13 @@ so that we can apply CSS-filters to change the arrow color in themes */
 	margin-bottom: 5px;
 	font-size: 0.875rem;
 	font-weight: normal;
+	color: var(--main-color);
+	background-color: var(--stab-background-color);
+}
+
+.stab.portability > code {
+	background: none;
+	color: var(--stab-code-color);
 }
 
 .stab .emoji {

src/librustdoc/html/static/css/themes/ayu.css

@@ -37,6 +37,8 @@ Original by Dempfi (https://github.com/dempfi/ayu)
 	--link-color: #39afd7;
 	--sidebar-link-color: #53b1db;
 	--sidebar-current-link-background-color: transparent;
+	--stab-background-color: #314559;
+	--stab-code-color: #e6e1cf;
 }
 
 .slider {
@@ -155,16 +157,6 @@ details.rustdoc-toggle > summary::before {
 	color: #000;
 }
 
-.stab {
-	color: #c5c5c5;
-	background: #314559 !important;
-}
-
-.stab.portability > code {
-	color: #e6e1cf;
-	background: none;
-}
-
 .result-name .primitive > i, .result-name .keyword > i {
 	color: #788797;
 }

src/librustdoc/html/static/css/themes/dark.css

@@ -32,6 +32,8 @@
 	--link-color: #d2991d;
 	--sidebar-link-color: #fdbf35;
 	--sidebar-current-link-background-color: #444;
+	--stab-background-color: #314559;
+	--stab-code-color: #e6e1cf;
 }
 
 .slider {
@@ -114,13 +116,6 @@ details.rustdoc-toggle > summary::before {
 	filter: invert(69%) sepia(60%) saturate(6613%) hue-rotate(184deg) brightness(100%) contrast(91%);
 }
 
-.stab { background: #314559; }
-
-.stab.portability > code {
-	color: #e6e1cf;
-	background: none;
-}
-
 .src-line-numbers :target { background-color: transparent; }
 
 /* Code highlighting */

src/librustdoc/html/static/css/themes/light.css

@@ -32,6 +32,8 @@
 	--link-color: #3873ad;
 	--sidebar-link-color: #356da4;
 	--sidebar-current-link-background-color: #fff;
+	--stab-background-color: #fff5d6;
+	--stab-code-color: #000;
 }
 
 .slider {
@@ -102,9 +104,6 @@ body.source .example-wrap pre.rust a {
 	filter: invert(44%) sepia(18%) saturate(23%) hue-rotate(317deg) brightness(96%) contrast(93%);
 }
 
-.stab { background: #FFF5D6; border-color: #FFC600; }
-.stab.portability > code { background: none; }
-
 .src-line-numbers :target { background-color: transparent; }
 
 /* Code highlighting */