doc: normalize CSS variable names and indentation

PR-URL: #39199 Reviewed-By: Antoine du Hamel <[email protected]> Reviewed-By: Zijian Liu <[email protected]>

Author: Trott

doc/api_assets/style.css

@@ -25,7 +25,8 @@
 --gray7:#c1c1c1;
 --grey8:#ddd;
 
---api-stability-links-bg:rgba(255,255,255,.4);
+--background-color-api-stability-link:rgba(255,255,255,.4);
+--background-color-highlight:var(--white-smoke);
 --color-brand-primary:var(--gray6);
 --color-brand-secondary:var(--green1);
 --color-fill-app:var(--white);
@@ -34,21 +35,20 @@
 --color-text-nav:var(--gray3);
 --color-text-primary:var(--gray6);
 --color-text-secondary:var(--green2);
---highlight-background-color:var(--white-smoke);
 }
 
 .dark-mode{
---color-fill-app:var(--black1);
---color-fill-side-nav:var(--black3);
---color-links:var(--green5);
---color-text-primary:var(--white);
---highlight-background-color:var(--black2);
+--background-color-highlight:var(--black2);
+--color-fill-app:var(--black1);
+--color-fill-side-nav:var(--black3);
+--color-links:var(--green5);
+--color-text-primary:var(--white);
 }
 
 .dark-modecode,
 .dark-modett{
 color:var(--grey-smoke);
-background-color:var(--highlight-background-color);
+background-color:var(--background-color-highlight);
 }
 .dark-modeacode{
 color:var(--green3);
@@ -248,7 +248,7 @@ ol.version-picker li:last-child a{
 .api_stabilitya:hover,
 .api_stabilitya:active,
 .api_stabilitya:focus{
-background-color:var(--api-stability-links-bg);
+background-color:var(--background-color-api-stability-link);
 }
 
 .api_stabilityacode{
@@ -455,7 +455,7 @@ code{
 pre{
 padding:1rem;
 vertical-align: top;
-background-color:var(--highlight-background-color);
+background-color:var(--background-color-highlight);
 margin:1rem;
 overflow-x: auto;
 }