Fix sponsor footer contrast on the dark footer

css/site.css

@@ -901,6 +901,8 @@ html.js [data-rv].rv-in { opacity: 1; transform: none; }
 .sponsor-foot {
   margin: 10px 0 0;
   font-size: var(--step-sm);
-  color: var(--muted);
+  color: rgba(246, 236, 218, 0.72);
 }
-.sponsor-foot .sponsor-label { margin-right: 6px; }
+.sponsor-foot .sponsor-label { margin-right: 6px; color: var(--sand); }
+.sponsor-foot a { color: rgba(246, 236, 218, 0.92); text-decoration-color: var(--oak); text-underline-offset: 3px; }
+.sponsor-foot a:hover { color: var(--sand); }