fix(a11y): address axe color-contrast violations on dark surface

styles/base/colors.css

@@ -29,8 +29,10 @@
   --color-secondary-800: color-mix(in oklch, var(--color-secondary) 80%, white);
   --color-secondary-900: color-mix(in oklch, var(--color-secondary) 90%, white);
 
-  --color-bodylinks: oklch(0.48 0.0789 211.58);
-  --color-footlinks: oklch(0.65 0.1104 212.2);
+  /* WCAG AA on --color-page-base (#100e0b): ~7:1 contrast, also visually
+   * distinct from surrounding --color-on-surface (#e3e1e9) for inline links. */
+  --color-bodylinks: oklch(0.68 0.16 250);
+  --color-footlinks: oklch(0.68 0.16 250);
 
   --color-light:     oklch(98.16% 0.0017 247.8);
   --color-dark:      oklch(34.51% 0.0133 248.2);

styles/base/typography.css

@@ -120,6 +120,14 @@ a, .link {
     &:hover { color: var(--color-primary); }
 }
 
+/* Inline links inside flowing text need an underline so they remain
+ * distinguishable from surrounding text without relying solely on color
+ * (WCAG 2.4.4 / axe link-in-text-block). */
+p a, li a, dd a, td a, blockquote a {
+    text-decoration: underline;
+    text-underline-offset: 2px;
+}
+
 h1 a, .h1 a,
 h2 a, .h2 a,
 h3 a, .h3 a {