fix: defensive CSS hidden rule, cache MediaQueryList, guard setSheetSnap

- Add [hidden] { display: none !important } to prevent CSS specificity overrides
- Cache matchMedia query instead of creating new MediaQueryList per call
- Guard setSheetSnap against being called on desktop

Co-Authored-By: Claude Opus 4.6 <[email protected]>

unredact/static/main.js

@@ -16,7 +16,8 @@ import { stopSolve, acceptSolution, initSolver } from './solver.js';
 
 // ── Sheet snap management ──
 
-const isMobile = () => window.matchMedia('(max-width: 768px)').matches;
+const mobileQuery = window.matchMedia('(max-width: 768px)');
+const isMobile = () => mobileQuery.matches;
 
 const SNAP_PEEK = 60;
 const SNAP_HALF_RATIO = 0.45;
@@ -37,6 +38,7 @@ function getSnapHeight(snap) {
 
 function setSheetSnap(snap) {
   sheetSnap = snap;
+  if (!isMobile()) return;
   const h = getSnapHeight(snap);
   document.documentElement.style.setProperty('--sheet-height', h + 'px');
   bottomSheet.style.height = h + 'px';
@@ -153,7 +155,7 @@ function handleLayoutChange() {
   }
 }
 
-window.matchMedia('(max-width: 768px)').addEventListener('change', handleLayoutChange);
+mobileQuery.addEventListener('change', handleLayoutChange);
 
 
 // ── Font loading ──

unredact/static/style.css

@@ -1,4 +1,5 @@
 * { margin: 0; padding: 0; box-sizing: border-box; }
+[hidden] { display: none !important; }
 
 :root {
   --bg-base: #1a1a2e;