.game-container {
    max-width: 600px;
    margin: 0 auto;
    padding: 20px;
    font-family: Arial, sans-serif;
}

h1 {
    text-align: center;
    color: #333;
}

.status {
    text-align: center;
    font-size: 20px;
    margin: 20px 0;
    color: #666;
}

.board {
    display: grid;
    grid-template-columns: repeat(15, 1fr);
    grid-template-rows: repeat(15, 1fr);
    width: 100%;
    aspect-ratio: 1/1;
    background-color: #e9c275;
    border: 10px solid #8b4513;
    border-radius: 5px;
    box-shadow: 0 0 10px rgba(0,0,0,0.3);
    background-image: 
        linear-gradient(to right, #333 1px, transparent 1px),
        linear-gradient(to bottom, #333 1px, transparent 1px);
    background-size: calc((100% - 20px) / 14) calc((100% - 20px) / 14);
    background-position: 10px 10px;
    position: relative;
}

.cell {
    position: relative;
    cursor: pointer;
}

.cell::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 0;
    width: 100%;
    height: 1px;
    background-color: transparent;
}

.cell::after {
    content: '';
    position: absolute;
    top: 0;
    left: 50%;
    width: 1px;
    height: 100%;
    background-color: transparent;
}

.stone {
    position: absolute;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    box-shadow: 0 2px 5px rgba(0,0,0,0.3);
    z-index: 1;
}

.black-stone {
    background-color: #000;
}

.white-stone {
    background-color: #fff;
}

.controls {
    text-align: center;
    margin-top: 20px;
    display: flex;
    gap: 10px;
    justify-content: center;
}

#start-btn, #undo-btn, #reset-btn {
    padding: 10px 20px;
    font-size: 16px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: background-color 0.3s;
}

#start-btn {
    background-color: #4CAF50;
    color: white;
}

#start-btn:hover {
    background-color: #45a049;
}

#undo-btn {
    background-color: #2196F3;
    color: white;
}

#undo-btn:disabled {
    background-color: #cccccc;
    cursor: not-allowed;
}

#undo-btn:hover:not(:disabled) {
    background-color: #0b7dda;
}

#reset-btn {
    background-color: #f44336;
    color: white;
}

#reset-btn:hover {
    background-color: #45a049;
}

@media (max-width: 600px) {
    .game-container {
        padding: 10px;
    }
    .status {
        font-size: 18px;
    }
    #restart-btn {
        padding: 8px 16px;
        font-size: 14px;
    }
}