* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Noto Sans TC', sans-serif;
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
    color: #fff;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    padding: 20px;
}

.container {
    max-width: 800px;
    width: 100%;
    text-align: center;
}

.game-header {
    margin-bottom: 30px;
}

h1 {
    font-size: 2.5em;
    color: #fff;
    text-shadow: 0 0 10px rgba(255, 255, 255, 0.5);
    margin-bottom: 20px;
    animation: glow 2s ease-in-out infinite alternate;
}

@keyframes glow {
    from {
        text-shadow: 0 0 10px rgba(255, 255, 255, 0.5);
    }
    to {
        text-shadow: 0 0 20px rgba(255, 255, 255, 0.8),
                     0 0 30px rgba(255, 255, 255, 0.6);
    }
}

.player-info {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 20px;
    margin-bottom: 20px;
}

.player {
    background: rgba(255, 255, 255, 0.1);
    padding: 15px 25px;
    border-radius: 10px;
    display: flex;
    flex-direction: column;
    gap: 5px;
    min-width: 200px;
}

.player-black {
    border: 2px solid #ffd700;
}

.player-white {
    border: 2px solid #fff;
}

.player-icon {
    font-size: 2em;
}

.player-name {
    font-weight: bold;
    color: #fff;
}

.player-score {
    font-size: 0.9em;
    color: #aaa;
}

#vs {
    font-size: 1.5em;
    font-weight: bold;
    color: #ff6b6b;
    text-shadow: 0 0 10px rgba(255, 107, 107, 0.5);
}

.game-controls {
    margin-bottom: 20px;
}

.mode-select {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 15px;
}

.mode-btn {
    padding: 12px 24px;
    font-size: 1.1em;
    background: rgba(255, 255, 255, 0.1);
    color: white;
    border: 2px solid transparent;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

.mode-btn:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

.mode-btn.active {
    background: #4ecdc4;
    border-color: #fff;
}

.btn-icon {
    font-size: 1.2em;
}

.difficulty-select {
    background: rgba(255, 255, 255, 0.1);
    padding: 12px;
    border-radius: 8px;
    display: inline-flex;
    align-items: center;
    gap: 10px;
}

.difficulty-label {
    color: #fff;
    font-size: 1.1em;
}

#ai-level {
    padding: 8px 16px;
    font-size: 1em;
    background: rgba(255, 255, 255, 0.2);
    color: #fff;
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 4px;
    cursor: pointer;
}

#ai-level option {
    background: #16213e;
    color: #fff;
}

.game-status {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 20px;
    margin-bottom: 20px;
}

.turn-indicator {
    font-size: 1.2em;
    color: #fff;
    background: rgba(255, 255, 255, 0.1);
    padding: 10px 20px;
    border-radius: 8px;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
    100% {
        transform: scale(1);
    }
}

.restart-btn {
    padding: 10px 20px;
    font-size: 1.1em;
    background: #ff6b6b;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

.restart-btn:hover {
    background: #ff5252;
    transform: scale(1.05);
}

.board-container {
    position: relative;
    display: inline-block;
}

#board {
    background: linear-gradient(135deg, #deb887 0%, #d4a76a 100%);
    border: 3px solid #8B4513;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.3);
}

.game-message {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(0, 0, 0, 0.8);
    color: #fff;
    padding: 20px 40px;
    border-radius: 10px;
    font-size: 1.5em;
    display: none;
}

.game-message.show {
    display: block;
    animation: fadeIn 0.5s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translate(-50%, -60%);
    }
    to {
        opacity: 1;
        transform: translate(-50%, -50%);
    }
}

@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    .player-info {
        flex-direction: column;
        gap: 10px;
    }
    
    #vs {
        margin: 10px 0;
    }
    
    .game-controls {
        flex-direction: column;
    }
    
    #board {
        width: 100%;
        height: auto;
    }
}