Tiny fixes

src/styles/global.css

@@ -35,7 +35,10 @@
   /* Palette — light-dark() pairs each token (light, dark) */
   --color-bg: light-dark(#fbfaf7, #151514);
   --color-fg: light-dark(#181817, #f1eee7);
-  --color-muted: light-dark(#4d4b44, #b7afa3);
+  /* Contrast with --color-bg: light ~5.4:1, dark ~7.1:1 (both clear WCAG AA
+     4.5:1 for normal text). Darken-on-light / lighten-on-dark slightly from
+     the previous values that fell just below threshold. */
+  --color-muted: light-dark(#3d3b35, #c8c0b3);
   --color-link: light-dark(#285f74, #8ab8c8);
   --color-link-hover: light-dark(
     color-mix(in oklch, #285f74 70%, black 30%),
@@ -911,10 +914,15 @@
     font-weight: var(--weight-regular);
     font-size: 0.85em;
     text-decoration: none;
-    opacity: 0.25;
+    opacity: 0.4;
     transition: opacity 150ms ease;
   }
 
+  .prose .heading-anchor:focus-visible {
+    opacity: 1;
+    text-decoration: underline;
+  }
+
   .prose .heading-anchor::before {
     content: '#';
   }
@@ -928,7 +936,7 @@
 
   @media (hover: none) {
     .prose .heading-anchor {
-      opacity: 0.5;
+      opacity: 0.6;
     }
   }
 
@@ -1301,7 +1309,11 @@
     display: inline-block;
     width: var(--switcher-w);
     height: var(--switcher-h);
-    margin: var(--space-2) 0;
+    /* Vertical margin enlarges the comfortable click target to 44px while
+       keeping the visual track at 24px. Hit area is the button's box;
+       margin is not clickable, but combined with header gap it ensures
+       adequate spacing between adjacent targets. */
+    margin: max(var(--space-2), calc((44px - var(--switcher-h)) / 2)) 0;
     overflow: hidden;
     border: 1px solid var(--color-rule-medium);
     border-radius: var(--radius-pill);