* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            display: flex;
            justify-content: center;
            align-items: center;
            min-height: 100vh;
            background: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
            color: #fff;
            padding: 20px;
        }
        
        .container {
            display: flex;
            flex-direction: column;
            gap: 20px;
            max-width: 1200px;
            width: 100%;
        }
        
        /* Player Selection Screen */
        .selection-screen {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            background: rgba(22, 33, 62, 0.95);
            display: flex;
            justify-content: center;
            align-items: center;
            z-index: 100;
        }
        
        .selection-box {
            background: #2d4059;
            border-radius: 15px;
            padding: 30px;
            width: 90%;
            max-width: 500px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
            text-align: center;
        }
        
        .selection-title {
            font-size: 2rem;
            margin-bottom: 20px;
            color: #e94560;
        }
        
        .selection-options {
            display: flex;
            flex-direction: column;
            gap: 15px;
            margin-bottom: 25px;
        }
        
        .selection-btn {
            padding: 15px;
            border: none;
            border-radius: 8px;
            background: #394867;
            color: white;
            font-size: 1.1rem;
            font-weight: bold;
            cursor: pointer;
            transition: all 0.3s ease;
        }
        
        .selection-btn:hover {
            background: #455777;
            transform: translateY(-3px);
        }
        
        .player-names {
            display: none;
            flex-direction: column;
            gap: 15px;
            margin-top: 20px;
        }
        
        .name-input {
            padding: 12px 15px;
            border: none;
            border-radius: 5px;
            background: #1a1a2e;
            color: white;
            font-size: 1rem;
        }
        
        .start-btn {
            padding: 12px 20px;
            border: none;
            border-radius: 5px;
            background: #e94560;
            color: white;
            font-weight: bold;
            cursor: pointer;
            transition: all 0.3s ease;
            margin-top: 15px;
        }
        
        .start-btn:hover {
            background: #ff6b6b;
            transform: translateY(-2px);
        }
        
        header {
            background: linear-gradient(to right, #2d4059, #1e3a5f);
            border-radius: 10px;
            padding: 15px 20px;
            display: flex;
            justify-content: space-between;
            align-items: center;
            flex-wrap: wrap;
            box-shadow: 0 5px 15px rgba(0, 0, 0, 0.4);
            position: relative;
            overflow: hidden;
        }
        
        header::before {
            content: '';
            position: absolute;
            top: 0;
            left: 0;
            width: 100%;
            height: 3px;
            background: linear-gradient(to right, #e94560, #7ec850);
        }
        
        .logo {
            display: flex;
            align-items: center;
            gap: 10px;
        }
        
        .logo i {
            font-size: 2rem;
            color: #e94560;
        }
        
        .logo h1 {
            font-size: 1.8rem;
            background: linear-gradient(45deg, #e94560, #7ec850);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
            text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
        }
        
        .header-controls {
            display: flex;
            align-items: center;
            gap: 15px;
            flex-wrap: wrap;
        }
        
        .difficulty-selector {
            position: relative;
        }
        
        .difficulty-dropdown {
            appearance: none;
            padding: 10px 40px 10px 15px;
            border-radius: 5px;
            border: none;
            background-color: #394867;
            color: white;
            font-weight: 500;
            cursor: pointer;
            width: 180px;
            box-shadow: 0 3px 5px rgba(0, 0, 0, 0.2);
            transition: all 0.3s ease;
        }
        
        .difficulty-dropdown:hover {
            background-color: #455777;
        }
        
        .dropdown-arrow {
            position: absolute;
            right: 12px;
            top: 50%;
            transform: translateY(-50%);
            pointer-events: none;
            color: #e94560;
        }
        
        .header-btn {
            display: flex;
            align-items: center;
            gap: 8px;
            padding: 10px 15px;
            border: none;
            border-radius: 5px;
            background: linear-gradient(to right, #e94560, #ff6b6b);
            color: white;
            font-weight: bold;
            cursor: pointer;
            transition: all 0.3s ease;
            box-shadow: 0 3px 5px rgba(0, 0, 0, 0.2);
        }
        
        .header-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 5px 8px rgba(0, 0, 0, 0.3);
        }
        
        .header-btn.undo {
            background: linear-gradient(to right, #4e54c8, #8f94fb);
        }
        
        .game-info {
            display: flex;
            align-items: center;
            gap: 15px;
            background: rgba(255, 255, 255, 0.1);
            padding: 10px 15px;
            border-radius: 5px;
            box-shadow: 0 3px 5px rgba(0, 0, 0, 0.2);
        }
        
        .status {
            font-size: 1rem;
            font-weight: bold;
            color: #7ec850;
            display: flex;
            align-items: center;
            gap: 5px;
        }
        
        .status i {
            color: #e94560;
        }
        
        .player-info {
            display: flex;
            align-items: center;
            gap: 5px;
            font-weight: 500;
        }
        
        .player-color {
            width: 15px;
            height: 15px;
            border-radius: 50%;
            display: inline-block;
        }
        
        .player-color.white {
            background: linear-gradient(135deg, #f0d9b5, #b58863);
        }
        
        .player-color.black {
            background: linear-gradient(135deg, #2d4059, #1a1a2e);
        }
        
        .game-container {
            display: flex;
            flex-direction: column;
            gap: 20px;
        }
        
        .chess-board {
            background-color: #2d4059;
            border-radius: 10px;
            padding: 20px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
            display: flex;
            justify-content: center;
        }
        
        .board {
            display: grid;
            grid-template-columns: repeat(8, 1fr);
            grid-template-rows: repeat(8, 1fr);
            width: 100%;
            max-width: 500px;
            aspect-ratio: 1/1;
            border: 4px solid #222;
        }
        
        .square {
            display: flex;
            justify-content: center;
            align-items: center;
            font-size: 2.5rem;
            cursor: pointer;
            transition: all 0.2s ease;
        }
        
        .square.light {
            background-color: #f0d9b5;
        }
        
        .square.dark {
            background-color: #b58863;
        }
        
        .square.selected {
            background-color: #7ec850;
        }
        
        .square.valid-move {
            position: relative;
        }
        
        .square.valid-move::after {
            content: '';
            position: absolute;
            width: 25%;
            height: 25%;
            border-radius: 50%;
            background-color: rgba(0, 0, 0, 0.2);
        }
        
        .square.check {
            background-color: #ff6b6b;
        }
        
        .captured-container {
            background-color: #2d4059;
            border-radius: 10px;
            padding: 20px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
        }
        
        .captured-pieces {
            display: flex;
            flex-direction: column;
            gap: 15px;
        }
        
        .captured-section {
            display: flex;
            flex-wrap: wrap;
            gap: 10px;
            align-items: center;
            background: #394867;
            padding: 15px;
            border-radius: 8px;
        }
        
        .captured-label {
            font-size: 1.1rem;
            font-weight: bold;
            color: #7ec850;
            min-width: 80px;
        }
        
        .captured-items {
            display: flex;
            gap: 5px;
            font-size: 1.8rem;
            flex-wrap: wrap;
        }
        
        @media (min-width: 768px) {
            .game-container {
                flex-direction: row;
                align-items: flex-start;
            }
            
            .chess-board {
                flex: 2;
            }
            
            .captured-container {
                flex: 1;
            }
            
            .captured-pieces {
                flex-direction: row;
            }
            
            .captured-section {
                flex: 1;
                flex-direction: column;
                align-items: flex-start;
                min-width: 150px;
            }
        }
        
        @media (max-width: 900px) {
            header {
                flex-direction: column;
                gap: 15px;
                align-items: flex-start;
            }
            
            .header-controls {
                width: 100%;
                justify-content: space-between;
            }
        }
        
        @media (max-width: 600px) {
            .header-controls {
                flex-direction: column;
                align-items: flex-start;
            }
            
            .game-info {
                width: 100%;
                justify-content: space-between;
            }
            
            .board {
                max-width: 100%;
            }
            
            .square {
                font-size: 2rem;
            }
            
            .selection-box {
                padding: 20px;
            }
            
            .selection-title {
                font-size: 1.7rem;
            }
        }