body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    margin: 0;
    padding: 20px;
    background: #f5f5f5;
    color: #333;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
}

h1 {
    text-align: center;
    margin-bottom: 30px;
    font-size: 2em;
    font-weight: normal;
    color: #000;
}

.game-container {
    background: #fff;
    padding: 30px;
    border: 1px solid #ddd;
    max-width: 1200px;
}

.controls {
    text-align: center;
    margin-bottom: 20px;
}

.controls button {
    background: #444;
    border: none;
    padding: 10px 20px;
    margin: 0 10px;
    color: white;
    font-size: 14px;
    cursor: pointer;
    border-radius: 4px;
}

.controls button:hover {
    background: #222;
}

.game-info {
    text-align: center;
    margin-bottom: 20px;
    font-size: 16px;
}

.keyboard-hint {
    font-size: 12px;
    margin-top: 5px;
    color: #666;
}

.multi-board-container {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-bottom: 20px;
}

.board-wrapper {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.board-header {
    font-size: 16px;
    margin-bottom: 10px;
    font-weight: bold;
}

.board {
    background: #eee;
    padding: 10px;
    border: 1px solid #ccc;
    min-width: 250px;
}

.active-board {
    border: 2px solid #333;
    background: #fff;
}

.inactive-board {
    opacity: 0.5;
}

.completed-board {
    opacity: 0.7;
    border: 1px solid #999;
}

.column-buttons {
    display: flex;
    justify-content: center;
    margin-bottom: 5px;
}

.column-btn {
    width: 35px;
    height: 25px;
    margin: 0 1px;
    background: #ddd;
    border: 1px solid #bbb;
    color: #333;
    font-size: 10px;
    cursor: pointer;
}

.column-btn:hover:not(:disabled) {
    background: #ccc;
}

.column-btn:disabled {
    background: #f0f0f0;
    color: #aaa;
    cursor: default;
    border-color: #eee;
}

.column-btn.highlight {
    background: #bbb;
}

.grid {
    display: grid;
    grid-template-columns: repeat(7, 35px);
    grid-gap: 2px;
    background: #ccc;
    padding: 2px;
}

.cell {
    width: 35px;
    height: 35px;
    background: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    border-radius: 50%;
}

.cell.player-o {
    background: #d32f2f; /* Red/Maroon - flat */
}

.cell.player-x {
    background: #fbc02d; /* Yellow - flat */
}

.board-result {
    margin-top: 10px;
    font-size: 14px;
    font-weight: bold;
    height: 20px;
    color: #333;
}

.board-result.win {
    color: #2e7d32;
}

.board-result.lose {
    color: #c62828;
}

.board-result.tie {
    color: #f57f17;
}

.game-over-message {
    font-size: 24px;
    color: #333;
    margin-top: 10px;
}

.ai-lastmove {
    margin-top: 5px;
    font-size: 12px;
    color: #666;
    text-align: center;
}

/* Responsive design */
@media (max-width: 768px) {
    .multi-board-container {
        grid-template-columns: 1fr;
    }
}