/* Modern Premium Chess - Elite Design */

:root {
    /* Color Palette - Dark Theme */
    --bg-primary: #0a0e27;
    --bg-secondary: #131829;
    --bg-tertiary: #1a1f3a;
    --bg-elevated: #1e2439;
    
    /* Accent Colors */
    --accent-primary: #00d4ff;
    --accent-secondary: #7c3aed;
    --accent-tertiary: #f59e0b;
    
    /* Board Colors */
    --light-square: #e8dcc1;
    --dark-square: #b58863;
    --board-border: #2d3548;
    
    /* Text Colors */
    --text-primary: #ffffff;
    --text-secondary: #9ca3af;
    --text-tertiary: #6b7280;
    
    /* Semantic Colors */
    --success: #10b981;
    --warning: #f59e0b;
    --error: #ef4444;
    --info: #3b82f6;
    
    /* Shadows & Effects */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.2);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 16px 64px rgba(0, 0, 0, 0.4);
    
    --glow-primary: 0 0 30px rgba(0, 212, 255, 0.3);
    --glow-secondary: 0 0 30px rgba(124, 58, 237, 0.3);
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-slow: 0.5s ease;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
}

/* Reset & Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Animated Background */
.background-container {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    overflow: hidden;
}

.gradient-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(100px);
    opacity: 0.15;
    animation: float 20s ease-in-out infinite;
}

.orb-1 {
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, var(--accent-primary), transparent);
    top: -200px;
    left: -200px;
    animation-delay: 0s;
}

.orb-2 {
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, var(--accent-secondary), transparent);
    bottom: -150px;
    right: -150px;
    animation-delay: 7s;
}

.orb-3 {
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, var(--accent-tertiary), transparent);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation-delay: 14s;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(30px, -30px) scale(1.1); }
    66% { transform: translate(-20px, 20px) scale(0.9); }
}

.chess-pattern {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        linear-gradient(rgba(255, 255, 255, 0.01) 1px, transparent 1px),
        linear-gradient(90deg, rgba(255, 255, 255, 0.01) 1px, transparent 1px);
    background-size: 50px 50px;
    opacity: 0.5;
}

/* Glass Effect */
.glass-effect {
    background: rgba(26, 31, 58, 0.7);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: var(--shadow-lg);
}

/* Main Layout */
.game-container {
    display: grid;
    grid-template-columns: 320px 1fr 320px;
    gap: 24px;
    max-width: 1800px;
    margin: 0 auto;
    padding: 24px;
    min-height: 100vh;
}

/* Sidebar Common Styles */
.left-sidebar,
.right-sidebar {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

/* Player Cards */
.player-card {
    padding: 24px;
    border-radius: var(--radius-lg);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.player-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-primary), var(--accent-secondary));
    opacity: 0;
    transition: opacity var(--transition-base);
}

.player-card.active::before {
    opacity: 1;
}

.player-card.active {
    box-shadow: var(--glow-primary);
    border-color: var(--accent-primary);
}

.player-avatar {
    width: 80px;
    height: 80px;
    margin: 0 auto 16px;
    position: relative;
}

.avatar-ring {
    position: absolute;
    inset: -4px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    animation: rotate 3s linear infinite;
}

@keyframes rotate {
    to { transform: rotate(360deg); }
}

.avatar-icon {
    position: absolute;
    inset: 4px;
    border-radius: 50%;
    background: var(--bg-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 48px;
}

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

.player-name {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 8px;
}

.player-rating {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.rating-badge {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    padding: 4px 12px;
    border-radius: 12px;
    font-weight: 700;
    font-size: 14px;
}

.rating-label {
    color: var(--text-secondary);
    font-size: 12px;
}

/* Hide Timer Sections */
.player-timer-container {
    display: none;
}

/* Captured Pieces */
.captured-pieces-container {
    padding-top: 16px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.captured-label {
    font-size: 12px;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 8px;
}

.captured-pieces {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    min-height: 40px;
}

.captured-piece {
    font-size: 28px;
    opacity: 0.8;
    transition: all var(--transition-fast);
    animation: fadeInScale 0.3s ease;
}

@keyframes fadeInScale {
    from {
        opacity: 0;
        transform: scale(0);
    }
    to {
        opacity: 0.8;
        transform: scale(1);
    }
}

.captured-piece:hover {
    opacity: 1;
    transform: scale(1.1);
}

.material-advantage {
    margin-top: 8px;
    font-weight: 700;
    font-size: 14px;
    text-align: center;
}

/* Stats Card */
.stats-card {
    padding: 20px;
    border-radius: var(--radius-lg);
}

.card-title {
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-primary);
}

.card-title .icon {
    font-size: 20px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
    margin-bottom: 20px;
}

.stat-item {
    background: var(--bg-primary);
    padding: 16px;
    border-radius: var(--radius-md);
    text-align: center;
    transition: all var(--transition-base);
}

.stat-item:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.stat-value {
    display: block;
    font-size: 24px;
    font-weight: 800;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 4px;
}

.stat-label {
    font-size: 12px;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Players Status */
.players-status {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.status-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px;
    background: var(--bg-primary);
    border-radius: var(--radius-sm);
    border-left: 3px solid transparent;
    transition: all var(--transition-base);
}

.status-item.active {
    border-left-color: var(--success);
    background: rgba(16, 185, 129, 0.1);
}

.status-item.waiting {
    border-left-color: var(--warning);
    opacity: 0.6;
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--text-tertiary);
}

.status-item.active .status-dot {
    background: var(--success);
    box-shadow: 0 0 10px var(--success);
    animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { transform: scale(1); opacity: 1; }
    50% { transform: scale(1.2); opacity: 0.8; }
}

/* Board Section */
.board-section {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

/* Game Header */
.game-header {
    padding: 20px 24px;
    border-radius: var(--radius-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 24px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    font-size: 32px;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo-text {
    font-size: 24px;
    font-weight: 800;
    letter-spacing: -0.5px;
}

.role-badge {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: var(--bg-primary);
    border-radius: 20px;
    font-size: 14px;
    font-weight: 600;
}

.badge-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--accent-primary);
    animation: pulse 2s ease-in-out infinite;
}

.connection-indicator {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    background: var(--bg-primary);
    border-radius: 20px;
}

.pulse-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--success);
    box-shadow: 0 0 10px var(--success);
    animation: pulse 2s ease-in-out infinite;
}

.connection-indicator.disconnected .pulse-dot {
    background: var(--error);
    box-shadow: 0 0 10px var(--error);
    animation: none;
}

.connection-text {
    font-size: 14px;
    font-weight: 600;
}

/* Board Container */
.board-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.board-wrapper {
    padding: 24px;
    border-radius: var(--radius-lg);
    position: relative;
}

.turn-indicator-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
}

.turn-indicator {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 24px;
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    font-size: 18px;
    font-weight: 700;
    position: relative;
    overflow: hidden;
}

.turn-indicator::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    animation: shimmer 2s infinite;
}

.turn-icon {
    font-size: 24px;
    animation: bounce 2s ease-in-out infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-5px); }
}

@keyframes shimmer {
    to { transform: translateX(100%); }
}

.status-badges {
    display: flex;
    gap: 8px;
}

.status-badge {
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 600;
    animation: fadeIn 0.3s ease;
}

.status-badge.check {
    background: var(--error);
    color: white;
    animation: shake 0.5s ease;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
}

/* Board Frame */
.board-frame {
    position: relative;
    display: inline-block;
}

.board-shadow {
    position: absolute;
    inset: -8px;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    border-radius: var(--radius-md);
    opacity: 0.15;
    filter: blur(20px);
}

.board-glow {
    position: absolute;
    inset: -2px;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    border-radius: var(--radius-md);
    opacity: 0;
    transition: opacity var(--transition-base);
    z-index: -1;
}

.board-wrapper:hover .board-glow {
    opacity: 0.2;
}

/* Chess Board */
.chessboard {
    display: grid;
    grid-template-columns: repeat(8, 80px);
    grid-template-rows: repeat(8, 80px);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-xl);
    position: relative;
    background: var(--dark-square);
}

/* Squares */
.square {
    width: 80px;
    height: 80px;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.square.light {
    background: var(--light-square);
}

.square.dark {
    background: var(--dark-square);
}

.square::before {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(circle, rgba(0, 212, 255, 0.2), transparent);
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.square:hover::before {
    opacity: 1;
}

.square.selected {
    background: linear-gradient(135deg, #7fb069, #6a9f5a) !important;
    box-shadow: inset 0 0 0 3px rgba(255, 255, 255, 0.5);
}

/* Premove Indicator */
.square.premove {
    position: relative;
}

.square.premove::after {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(245, 158, 11, 0.4);
    animation: premovePulse 1.5s ease-in-out infinite;
}

@keyframes premovePulse {
    0%, 100% { opacity: 0.4; }
    50% { opacity: 0.7; }
}

.square.last-move {
    position: relative;
}

.square.last-move::after {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(245, 158, 11, 0.3);
    animation: fadeOut 2s ease;
}

@keyframes fadeOut {
    to { opacity: 0; }
}

/* Coordinate Labels */
.rank-label, .file-label {
    position: absolute;
    font-size: 12px;
    font-weight: 700;
    opacity: 0.6;
    z-index: 1;
}

.square.light .rank-label,
.square.light .file-label {
    color: var(--dark-square);
}

.square.dark .rank-label,
.square.dark .file-label {
    color: var(--light-square);
}

.rank-label {
    top: 4px;
    left: 6px;
}

.file-label {
    bottom: 4px;
    right: 6px;
}

/* Chess Pieces */
.piece {
    font-size: 64px;
    cursor: grab;
    user-select: none;
    transition: transform var(--transition-fast);
    z-index: 10;
    position: relative;
}

.piece:hover {
    transform: scale(1.1);
}

.piece:active {
    cursor: grabbing;
    transform: scale(1.15);
}

.piece.white {
    color: #ffffff;
    filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.9)) 
            drop-shadow(0 0 2px rgba(0, 0, 0, 1));
}

.piece.black {
    color: #2d2d2d;
    filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.5)) 
            drop-shadow(0 0 2px rgba(255, 255, 255, 0.3));
}

/* Move Indicators */
.move-indicator {
    width: 24px;
    height: 24px;
    background: rgba(0, 212, 255, 0.5);
    border-radius: 50%;
    position: absolute;
    pointer-events: none;
    animation: scaleIn 0.2s ease;
    box-shadow: 0 0 10px rgba(0, 212, 255, 0.6);
}

@keyframes scaleIn {
    from { transform: scale(0); opacity: 0; }
    to { transform: scale(1); opacity: 1; }
}

.capture-indicator {
    width: 70px;
    height: 70px;
    border: 4px solid rgba(239, 68, 68, 0.7);
    border-radius: 50%;
    position: absolute;
    pointer-events: none;
    animation: captureIndicator 1.5s ease-in-out infinite;
}

@keyframes captureIndicator {
    0%, 100% { 
        transform: scale(1); 
        opacity: 0.7;
        border-color: rgba(239, 68, 68, 0.7);
    }
    50% { 
        transform: scale(1.05); 
        opacity: 1;
        border-color: rgba(239, 68, 68, 1);
    }
}

/* Board Flip Effect */
.chessboard.flipped {
    transform: rotate(180deg);
}

.chessboard.flipped .piece,
.chessboard.flipped .rank-label,
.chessboard.flipped .file-label {
    transform: rotate(180deg);
}

.chessboard.flipped .piece:hover {
    transform: rotate(180deg) scale(1.1);
}

/* Game Controls */
.game-controls {
    display: flex;
    gap: 12px;
    justify-content: center;
    flex-wrap: wrap;
}

.control-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 14px 24px;
    border: none;
    border-radius: var(--radius-md);
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: white;
}

.control-btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.control-btn:hover::before {
    width: 300px;
    height: 300px;
}

.control-btn .btn-icon {
    font-size: 20px;
    z-index: 1;
}

.control-btn .btn-text {
    z-index: 1;
}

.control-btn.primary {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    box-shadow: 0 4px 15px rgba(0, 212, 255, 0.3);
}

.control-btn.primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 212, 255, 0.4);
}

.control-btn.secondary {
    background: linear-gradient(135deg, #4b5563, #6b7280);
    box-shadow: 0 4px 15px rgba(75, 85, 99, 0.3);
}

.control-btn.secondary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(75, 85, 99, 0.4);
}

.control-btn.success {
    background: linear-gradient(135deg, var(--success), #059669);
    box-shadow: 0 4px 15px rgba(16, 185, 129, 0.3);
}

.control-btn.success:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(16, 185, 129, 0.4);
}

.control-btn.danger {
    background: linear-gradient(135deg, var(--error), #dc2626);
    box-shadow: 0 4px 15px rgba(239, 68, 68, 0.3);
}

.control-btn.danger:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(239, 68, 68, 0.4);
}

.control-btn:active {
    transform: translateY(0);
}

.control-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none !important;
}

/* History Card */
.history-card {
    padding: 20px;
    border-radius: var(--radius-lg);
    flex: 1;
    display: flex;
    flex-direction: column;
}

.move-history-container {
    flex: 1;
    margin-bottom: 16px;
}

.move-history {
    max-height: 400px;
    overflow-y: auto;
    padding: 12px;
    background: var(--bg-primary);
    border-radius: var(--radius-sm);
}

.move-history::-webkit-scrollbar {
    width: 8px;
}

.move-history::-webkit-scrollbar-track {
    background: var(--bg-secondary);
    border-radius: 4px;
}

.move-history::-webkit-scrollbar-thumb {
    background: linear-gradient(180deg, var(--accent-primary), var(--accent-secondary));
    border-radius: 4px;
}

.move-history::-webkit-scrollbar-thumb:hover {
    background: linear-gradient(180deg, var(--accent-secondary), var(--accent-primary));
}

.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: var(--text-secondary);
}

.empty-icon {
    font-size: 48px;
    display: block;
    margin-bottom: 12px;
    opacity: 0.5;
}

.move-item {
    padding: 12px 16px;
    margin-bottom: 8px;
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
    border-left: 3px solid var(--accent-primary);
    font-family: 'Courier New', monospace;
    font-size: 15px;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 12px;
    transition: all var(--transition-base);
}

.move-item:hover {
    transform: translateX(4px);
    background: var(--bg-tertiary);
}

.move-number {
    color: var(--text-secondary);
    min-width: 30px;
}

.history-controls {
    display: flex;
    gap: 8px;
    justify-content: center;
}

.history-btn {
    padding: 10px 16px;
    background: var(--bg-primary);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    cursor: pointer;
    transition: all var(--transition-base);
    font-size: 16px;
}

.history-btn:hover {
    background: var(--bg-tertiary);
    transform: translateY(-2px);
}

.history-btn:active {
    transform: translateY(0);
}

/* Modal */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.85);
    backdrop-filter: blur(10px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-base);
}

.modal-overlay.show {
    opacity: 1;
    pointer-events: all;
}

.modal {
    max-width: 500px;
    width: 90%;
    border-radius: var(--radius-xl);
    padding: 40px;
    transform: scale(0.9);
    transition: transform var(--transition-base);
}

.modal-overlay.show .modal {
    transform: scale(1);
}

.modal-header {
    text-align: center;
    margin-bottom: 24px;
}

.modal-title {
    font-size: 32px;
    font-weight: 800;
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.modal-body {
    text-align: center;
    margin-bottom: 32px;
}

.result-icon {
    font-size: 80px;
    margin-bottom: 16px;
    animation: iconBounce 1s ease infinite;
}

@keyframes iconBounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.result-message {
    font-size: 20px;
    color: var(--text-secondary);
    line-height: 1.6;
}

.modal-footer {
    display: flex;
    gap: 12px;
    justify-content: center;
}

.modal-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border: none;
    border-radius: var(--radius-md);
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-base);
    color: white;
}

.modal-btn.primary {
    background: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
}

.modal-btn.secondary {
    background: linear-gradient(135deg, #4b5563, #6b7280);
}

.modal-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* Toast Notifications */
.toast-container {
    position: fixed;
    top: 24px;
    right: 24px;
    z-index: 3000;
    display: flex;
    flex-direction: column;
    gap: 12px;
    max-width: 400px;
}

.toast {
    padding: 16px 24px;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-xl);
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 600;
    transform: translateX(500px);
    animation: slideInLeft 0.3s ease forwards;
    backdrop-filter: blur(20px);
}

@keyframes slideInLeft {
    to { transform: translateX(0); }
}

.toast.hide {
    animation: slideOutRight 0.3s ease forwards;
}

@keyframes slideOutRight {
    to { transform: translateX(500px); }
}

.toast.success {
    background: rgba(16, 185, 129, 0.9);
    border-left: 4px solid var(--success);
}

.toast.error {
    background: rgba(239, 68, 68, 0.9);
    border-left: 4px solid var(--error);
}

.toast.warning {
    background: rgba(245, 158, 11, 0.9);
    border-left: 4px solid var(--warning);
}

.toast.info {
    background: rgba(59, 130, 246, 0.9);
    border-left: 4px solid var(--info);
}

.toast-icon {
    font-size: 24px;
}

.toast-message {
    flex: 1;
}

.toast-close {
    background: none;
    border: none;
    color: white;
    cursor: pointer;
    font-size: 20px;
    padding: 0;
    opacity: 0.7;
    transition: opacity var(--transition-fast);
}

.toast-close:hover {
    opacity: 1;
}

/* Responsive Design */
@media (max-width: 1400px) {
    .game-container {
        grid-template-columns: 280px 1fr 280px;
        gap: 16px;
        padding: 16px;
    }

    .chessboard {
        grid-template-columns: repeat(8, 70px);
        grid-template-rows: repeat(8, 70px);
    }

    .square {
        width: 70px;
        height: 70px;
    }

    .piece {
        font-size: 56px;
    }
}

@media (max-width: 1100px) {
    .game-container {
        grid-template-columns: 1fr;
        max-width: 700px;
        margin: 0 auto;
    }

    .left-sidebar,
    .right-sidebar {
        display: none;
    }

    .chessboard {
        grid-template-columns: repeat(8, 65px);
        grid-template-rows: repeat(8, 65px);
    }

    .square {
        width: 65px;
        height: 65px;
    }

    .piece {
        font-size: 52px;
    }
}

@media (max-width: 600px) {
    body {
        padding: 10px;
    }

    .game-container {
        padding: 10px;
    }

    .chessboard {
        grid-template-columns: repeat(8, 45px);
        grid-template-rows: repeat(8, 45px);
    }

    .square {
        width: 45px;
        height: 45px;
    }

    .piece {
        font-size: 36px;
    }

    .control-btn {
        padding: 10px 16px;
        font-size: 13px;
    }

    .control-btn .btn-text {
        display: none;
    }

    .logo-text {
        display: none;
    }

    .toast-container {
        left: 10px;
        right: 10px;
        max-width: none;
    }
}

/* Loading Animation */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.fade-in {
    animation: fadeIn 0.5s ease;
}