Merge remote-tracking branch 'origin/master' into codex/pr57-p0-p2

# Conflicts:
#	docs/【玩法创作】平台入口与玩法链路-2026-05-15.md
#	docs/【项目基线】当前产品与工程约束-2026-05-15.md

src/index.css

@@ -4831,6 +4831,31 @@ html[data-mobile-keyboard-open='true'] .platform-mobile-bottom-dock {
     pointer-events: auto;
   }
 
+  .platform-recommend-runtime-visual {
+    position: absolute;
+    inset: 0;
+    min-width: 0;
+    overflow: hidden;
+    background: var(--platform-recommend-runtime-fill);
+  }
+
+  .platform-recommend-runtime-cover {
+    position: absolute;
+    inset: 0;
+    z-index: 3;
+    overflow: hidden;
+    background: var(--platform-recommend-runtime-fill);
+    opacity: 1;
+    pointer-events: auto;
+    transition: opacity 420ms ease;
+    will-change: opacity;
+  }
+
+  .platform-recommend-runtime-cover--hidden {
+    opacity: 0;
+    pointer-events: none;
+  }
+
   .platform-recommend-swipe-stage {
     position: relative;
     flex: 1 1 auto;