Turn the theme up, and let START GAME catch the light

Menu theme 0.5 -> 0.65.

The gold frame comes off START GAME — both buttons share the one slate border
now, so the pair reads as a pair, and a light sweeps across the START plate
instead: over in ~0.8s, then still for the rest of a 4.5s cycle. The sweep is a
::after with pointer-events:none so it can never eat the tap, and it is off
under prefers-reduced-motion.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

audio.js

@@ -120,7 +120,7 @@ export const zombieMusic = () => loopBed('zombie-mode.m4a', 800, 0.2, 20.47077);
 // — which is the loopEnd, because the decoded buffer is NOT (measured 48.0174 s in Chrome; see the
 // padding note in loopBed). Re-encode the file and you must re-measure that number:
 //   fetch(f).then(r=>r.arrayBuffer()).then(a=>new AudioContext().decodeAudioData(a)).then(b=>b.duration)
-export const menuMusic = () => loopBed('background-music.m4a', 30, 0.5, 48);
+export const menuMusic = () => loopBed('background-music.m4a', 30, 0.65, 48);
 
 // duck a bed to silence (out=true) or back to its base level over `secs` — the sudden-death duel mutes the music
 function fadeBed(file, out, secs = 0.7) {