body {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    margin: 0;
    font-family: sans-serif;
    background-color: #f0f0f0;
}

.game-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
}

.board {
    display: grid;
    grid-template-columns: repeat(6, 50px);
    grid-template-rows: repeat(6, 50px);
    border: 4px solid #333;
    background-color: #2e7d32;
}

.cell {
    width: 50px;
    height: 50px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
}

.cell.valid { background-color: rgba(255, 255, 255, 0.1); }

.stone {
    width: 80%;
    height: 80%;
    border-radius: 50%;
}

.black { background-color: #000; }
.white { background-color: #fff; border: 1px solid #ccc; }

.controls {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    padding: 15px;
    background: #fff;
    border-radius: 10px;
    width: 250px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}

.score {
    display: flex;
    justify-content: space-between;
    width: 100%;
    font-size: 1.2em;
    font-weight: bold;
}

.matta-container {
    display: flex;
    justify-content: space-between;
    width: 100%;
    font-size: 0.85em;
    color: #555;
    border-top: 1px solid #eee;
    padding-top: 5px;
}

.matta-item span {
    font-weight: bold;
    color: #d32f2f;
}

button {
    width: 100%;
    padding: 10px;
    border-radius: 5px;
    border: none;
    cursor: pointer;
    background: #007BFF;
    color: #fff;
}

#undo-button { background: #ffa000; font-weight: bold; }
#end-game-button { background: #e53935; }
button:disabled { background: #ccc; }