body {
            background-color: #1a202c;
            color: #e2e8f0;
            font-family: 'Inter', sans-serif;
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            height: 100vh;
            margin: 0;
            overflow: hidden;
        }

        .game-container {
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            width: 100%;
            max-width: 900px;
            padding: 1rem;
        }

        canvas {
            border: 4px solid #4a5568;
            border-radius: 12px;
            box-shadow: 0 10px 15px rgba(0, 0, 0, 0.3);
            background-color: #2d3748;
            touch-action: none;
        }

        .controls {
            display: flex;
            flex-direction: column;
            gap: 1rem;
            margin-top: 1.5rem;
            width: 100%;
            max-width: 400px;
        }

        .button {
            padding: 0.75rem 1.5rem;
            border-radius: 9999px;
            font-weight: bold;
            text-transform: uppercase;
            letter-spacing: 1px;
            transition: all 0.3s ease;
            cursor: pointer;
            box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1), 0 1px 3px rgba(0, 0, 0, 0.08);
        }

        .button.primary {
            background-image: linear-gradient(to right, #4c51bf, #667eea);
            color: white;
        }

        .button.secondary {
            background-color: #a0aec0;
            color: #1a202c;
        }

        .button:hover {
            transform: translateY(-2px);
            box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15), 0 2px 4px rgba(0, 0, 0, 0.1);
        }

        .status-message {
            font-size: 1.25rem;
            font-weight: bold;
            margin-bottom: 1rem;
            text-align: center;
            min-height: 2rem;
        }

        @media (max-width: 640px) {
            .controls {
                flex-direction: column;
            }
        }

        .piece-promotion-menu {
            position: absolute;
            background-color: rgba(0, 0, 0, 0.7);
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            display: flex;
            justify-content: center;
            align-items: center;
            z-index: 100;
        }

        .promotion-options {
            background-color: #2d3748;
            padding: 1.5rem;
            border-radius: 12px;
            box-shadow: 0 10px 20px rgba(0, 0, 0, 0.5);
            display: flex;
            gap: 1rem;
        }

        .promotion-option {
            background-color: #4a5568;
            padding: 1rem;
            border-radius: 8px;
            cursor: pointer;
            font-size: 2.5rem;
            transition: transform 0.2s;
        }
        .promotion-option:hover {
            transform: scale(1.1);
        }