doc: fix color contrast for anchor marks in dark mode

Trott · Trott · commit 8a640cf0c911 · 2021-06-27T05:08:46.000-07:00
Currently, in its dark mode, our website background color is #090C15 and
our anchor marks are #707070 for a contrast ratio of 3.94 to 1, falling
short of the WCAG AA 4.5 to 1. This changes the mark color in dark mode
only to #7A7A7A for a color contrast of 4.55 to 1.
diff --git a/doc/api_assets/style.css b/doc/api_assets/style.css
@@ -27,10 +27,11 @@
 
   --color-brand-primary: var(--gray6);
   --color-brand-secondary: var(--green1);
+  --color-text-nav: var(--gray3);
+  --color-text-mark: var(--gray1);
   --color-text-primary: var(--gray6);
   --color-text-secondary: var(--green2);
   --color-fill-app: var(--white);
-  --color-text-nav: var(--gray3);
   --highlight-background-color: var(--white-smoke);
   --color-links: var(--green1);
   --color-fill-side-nav: var(--gray6);
@@ -40,6 +41,7 @@
 .dark-mode {
     --color-links: var(--green5);
     --color-fill-app: var(--black1);
+    --color-text-mark: var(--gray5);
     --color-text-primary: var(--white);
     --color-fill-side-nav: var(--black3);
     --highlight-background-color: var(--black2);
@@ -632,7 +634,7 @@ a code {
 
 span > .mark,
 span > .mark:visited {
-  color: #707070;
+  color: var(--color-text-mark);
   position: absolute;
   top: 0;
   right: 0;
