#fifteen-puzzle-container {
    max-width: 420px;
    margin: 40px auto;
    font-family: Arial, sans-serif;
    text-align: center;
}

.puzzle-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 15px;
    align-items: center;
}

.puzzle-stats span {
    margin-right: 15px;
    font-size: 16px;
}

.puzzle-buttons button {
    padding: 6px 12px;
    margin-left: 5px;
    border: none;
    background-color: #0073aa;
    color: #fff;
    cursor: pointer;
    border-radius: 4px;
}

.puzzle-buttons button:hover {
    background-color: #005177;
}

.puzzle-board {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-gap: 8px;
    background: #ddd;
    padding: 10px;
    border-radius: 6px;
}

.puzzle-tile {
    background: #ffffff;
    font-size: 22px;
    font-weight: bold;
    padding: 20px 0;
    cursor: pointer;
    border-radius: 4px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.2);
    user-select: none;
    transition: background 0.2s ease;
}

.puzzle-tile:hover {
    background: #f1f1f1;
}

.puzzle-empty {
    background: transparent;
    box-shadow: none;
    cursor: default;
}

.game-message {
    margin-top: 15px;
    font-size: 18px;
    font-weight: bold;
    color: green;
}