.hint { text-align: center; color: #64748B; font-size: 0.9rem; margin-bottom: 0.75rem; }
.bubble-board { display: grid; grid-template-columns: repeat(6, 1fr); gap: 4px; max-width: 300px; padding: 8px; background: #0C4A6E; border-radius: 14px; }
.bubble { aspect-ratio: 1; border: none; border-radius: 50%; cursor: pointer; min-height: 40px; transition: transform 0.1s; }
.bubble:hover { transform: scale(1.08); }
.bubble.c0 { background: #EF4444; }
.bubble.c1 { background: #3B82F6; }
.bubble.c2 { background: #22C55E; }
.bubble.c3 { background: #EAB308; }
.bubble.c4 { background: #A855F7; }