* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
}

body {
    background: radial-gradient(circle at top, #1a0e0e 0%, #0a0505 100%);
    color: #f5f5f5;
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    min-height: 100vh;
    padding: 20px;
    padding-top: max(20px, env(safe-area-inset-top));
    padding-bottom: max(20px, env(safe-area-inset-bottom));
}

.container {
    max-width: 900px;
    margin: 0 auto;
}

header {
    text-align: center;
    margin-bottom: 30px;
    padding: 20px 10px;
}

header h1 {
    font-size: clamp(2rem, 6vw, 3.2rem);
    margin-bottom: 8px;
    text-shadow: 0 0 20px rgba(255, 50, 50, 0.6);
    letter-spacing: 2px;
}

.subtitle {
    color: #b0b0b0;
    font-size: clamp(0.85rem, 2.5vw, 1rem);
}

.hint {
    text-align: center;
    color: #777;
    font-size: 0.85rem;
    margin-top: 25px;
    padding: 10px;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
    gap: 16px;
    padding: 6px;
}

.sound-btn {
    background: linear-gradient(145deg, #2a1515, #1a0a0a);
    border: 2px solid #4a2020;
    border-radius: 12px;
    color: #f5f5f5;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    padding: 26px 16px;
    transition: all 0.15s ease;
    font-size: 1rem;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.5);
    -webkit-user-select: none;
    user-select: none;
}

.sound-btn:active {
    transform: scale(0.97);
    background: linear-gradient(145deg, #3a2020, #251010);
    border-color: #ff4444;
    box-shadow: 0 0 18px rgba(255, 68, 68, 0.5), 0 2px 10px rgba(0, 0, 0, 0.5);
}

.sound-btn.playing {
    border-color: #ff6666;
    box-shadow: 0 0 25px rgba(255, 68, 68, 0.7);
    animation: pulse 0.5s ease-in-out;
}

.icon {
    font-size: 2.4rem;
    filter: drop-shadow(0 0 10px rgba(255, 100, 100, 0.35));
}

.label {
    font-weight: 600;
    text-align: center;
    letter-spacing: 0.4px;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.03); }
}

@media (max-width: 600px) {
    .grid {
        grid-template-columns: 1fr;
    }
    .sound-btn {
        padding: 22px 14px;
    }
}