fix(resume): add fallback for --on-accent to fix text color

--on-accent is set by deferred JS module, so var(--on-accent) is
undefined on first paint. Added fallback hsl(0 0% 98%) to fab--label
so text is white before JS defines the token.

public/css/main.css

@@ -964,6 +964,7 @@ a.fab--secondary:visited {
   width: auto;
   padding: 0.65rem 1.1rem;
   gap: 0.5rem;
+  color: var(--on-accent, hsl(0 0% 98%));
 }
 
 .fab__label {