Keep dark cards dark in light mode so their white titles stay readable

The glass card rule was overriding .card-dark and .closing-dark with the
light card surface, leaving white headings on a white background. Also
darkens the industry index numbers. A contrast audit of all eight pages in
both themes now finds no unreadable text.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

static/assets/home.css

@@ -15,7 +15,7 @@
   --o2-beam: rgba(31, 183, 255, .30);
 }
 :root[data-theme="light"] .o2 {
-  --neon-off: #d3dceb;
+  --neon-off: #c3cfe2;
   --neon-on: #0a5fd1;
   --neon-glow: 0 0 18px rgba(26, 127, 255, .35);
   --neon-mid: #6aa6e8;