Merge pull request #25 from ssfinney/codex/design-and-build-rift-mode-feature-w1fbei

Add Rift Mode: detect unsolvable boards, show modal, persist state and styles

Author: ssfinney

index.html

@@ -63,6 +63,20 @@ <h1 class="splash-title">SHANDOKU</h1>
     </div>
   </div>
 
+  <div id="riftModal" class="rift-modal" hidden aria-modal="true" role="dialog" aria-labelledby="riftTitle">
+    <div class="rift-backdrop" id="riftBackdrop"></div>
+    <div class="rift-card">
+      <p class="rift-kicker">Rift Mode</p>
+      <h2 id="riftTitle">A seam in the pattern</h2>
+      <p id="riftBody" class="rift-body"></p>
+      <div class="rift-btns">
+        <button id="riftReturnBtn">Return to puzzle</button>
+        <button id="riftRestoreBtn">Restore last solvable</button>
+        <button id="riftFreshBtn" class="primary">Start fresh</button>
+      </div>
+    </div>
+  </div>
+
   <div class="app">
     <!-- Compact top bar: title | timer + errors | settings -->
     <div class="top-bar">