WIP: Add multiplayer Snake game

N-player (2-8) real-time Snake game alongside Connect 4.
Lobby has tabs to switch between games. Players join via
invite link with 10-second countdown. Game loop runs at
tick-based intervals with NATS pub/sub for state sync.

Keyboard input not yet working (Datastar keydown binding
issue still under investigation).

assets/css/input.css

@@ -61,3 +61,27 @@
 .player-chip { width: 20px; height: 20px; border-radius: 50%; background: #666; }
 .player-chip.red { background: #dc2626; }
 .player-chip.yellow { background: #facc15; }
+
+/* Snake game */
+.snake-board {
+  display: inline-grid;
+  gap: 0;
+  background: #1a1a2e;
+  border-radius: 8px;
+  overflow: hidden;
+  border: 3px solid #333;
+}
+.snake-row { display: contents; }
+.snake-cell {
+  background: #16213e;
+  border: 1px solid rgba(255,255,255,0.03);
+  transition: background 0.05s;
+}
+.snake-cell.snake-food {
+  background: #ff6b6b;
+  border-radius: 50%;
+  box-shadow: 0 0 6px rgba(255,107,107,0.6);
+}
+.snake-cell.snake-head { border-radius: 4px; }
+.snake-cell.snake-dead { opacity: 0.35; }
+.snake-wrapper:focus { outline: none; }