.fifteen-subtitle {
    text-align: center;
    margin-bottom: 14px;
}

.fifteen-panel {
    width: min(520px, 100%);
    margin-inline: auto;
    text-align: center;
}

.fifteen-status {
    min-height: 40px;
    margin-bottom: 12px;
    font-size: 20px;
}

.fifteen-board {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    width: min(92vw, 360px);
    margin: 0 auto 14px;
}

.fifteen-cell {
    aspect-ratio: 1 / 1;
    border: 3px solid var(--border);
    background: linear-gradient(180deg, #fef4d0 0%, #f4b860 100%);
    color: #3d2208;
    font-size: clamp(24px, 6vw, 34px);
    cursor: pointer;
    transition: transform 0.15s ease;
}

.fifteen-cell:hover:not(.blank):not(:disabled) {
    transform: translateY(-2px);
}

.fifteen-cell.blank {
    background: linear-gradient(180deg, #e7efe5 0%, #c2d8c6 100%);
    cursor: default;
}

.fifteen-controls {
    display: flex;
    justify-content: center;
}

.fifteen-moves {
    margin-top: 12px;
    font-size: 18px;
}