:root {
    --primary: #2c3e50;
    --primary-dark: #1a252f;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --light-square: #f0d9b5;
    --dark-square: #b58863;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-800: #1f2937;
}

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

html, body {
    width: 100%;
    min-height: 100vh;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #2c3e50 0%, #34495e 100%);
    color: white;
}

.hidden { display: none !important; }

/* Share Button */
.share-btn {
    position: fixed;
    top: 20px;
    right: 20px;
    background: var(--primary);
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 16px;
    font-weight: 600;
    box-shadow: 0 4px 12px rgba(0,0,0,0.3);
    z-index: 100;
    transition: all 0.3s ease;
}

.share-btn:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
}

/* Connection Status */
.connection-status {
    position: fixed;
    top: 20px;
    left: 20px;
    background: rgba(255, 255, 255, 0.95);
    color: var(--gray-800);
    padding: 8px 16px;
    border-radius: 20px;
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.2);
    z-index: 100;
}

.status-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--danger);
    animation: pulse 2s infinite;
}

.connection-status.connected .status-dot {
    background: var(--success);
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

/* Game Container */
.game-container {
    display: flex;
    flex-direction: column;
    width: 100vw;
    height: 100vh;
}

/* Header */
.game-header {
    background: rgba(0, 0, 0, 0.3);
    padding: 16px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    backdrop-filter: blur(10px);
}

.header-left {
    display: flex;
    align-items: center;
    gap: 16px;
}

.header-left h1 {
    font-size: 24px;
    margin: 0;
}

.room-badge {
    background: rgba(255, 255, 255, 0.1);
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 14px;
}

.game-status {
    font-size: 18px;
    font-weight: 600;
    text-align: center;
}

.turn-indicator {
    background: rgba(255, 255, 255, 0.1);
    padding: 8px 16px;
    border-radius: 20px;
    font-weight: 600;
}

/* Game Layout */
.game-layout {
    display: flex;
    flex: 1;
    overflow: hidden;
    padding: 20px;
    gap: 20px;
}

/* Sidebars */
.sidebar-left, .sidebar-right {
    width: 280px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

/* Player Panel */
.player-panel {
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.player-panel.active {
    border-color: var(--warning);
    box-shadow: 0 0 20px rgba(245, 158, 11, 0.3);
}

.player-icon {
    font-size: 48px;
    text-align: center;
}

.player-name {
    font-size: 18px;
    font-weight: 700;
    text-align: center;
}

.player-status {
    text-align: center;
    font-size: 14px;
    opacity: 0.7;
}

.captured-pieces {
    display: flex;
    flex-wrap: wrap;
    gap: 4px;
    min-height: 40px;
    background: rgba(0, 0, 0, 0.2);
    padding: 8px;
    border-radius: 8px;
}

.captured-piece {
    font-size: 20px;
}

/* Spectators */
.spectators-panel {
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    padding: 16px;
    flex: 1;
}

.spectators-panel h3 {
    margin-bottom: 12px;
    font-size: 16px;
}

.spectators-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.spectator-item {
    padding: 8px 12px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 6px;
    font-size: 14px;
}

/* Board Area */
.board-area {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
}

.chess-board {
    display: grid;
    grid-template-columns: repeat(8, 1fr);
    grid-template-rows: repeat(8, 1fr);
    width: 640px;
    height: 640px;
    border: 4px solid rgba(255, 255, 255, 0.2);
    border-radius: 8px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.5);
    background: white;
}

.chess-square {
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 48px;
    cursor: pointer;
    position: relative;
    transition: background-color 0.2s ease;
    user-select: none;
}

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

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

.chess-square.selected {
    background: rgba(255, 255, 0, 0.5) !important;
    box-shadow: inset 0 0 0 3px yellow;
}

.chess-square.valid-move {
    background: rgba(0, 255, 0, 0.3) !important;
}

.chess-square.valid-move::after {
    content: '●';
    position: absolute;
    font-size: 20px;
    color: rgba(0, 100, 0, 0.5);
}

.chess-square.last-move {
    background: rgba(255, 255, 100, 0.4) !important;
}

.chess-square:hover {
    filter: brightness(1.1);
}

/* Promotion Dialog */
.promotion-dialog {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: white;
    color: var(--gray-800);
    padding: 24px;
    border-radius: 12px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.5);
    z-index: 100;
}

.promotion-dialog h3 {
    margin-bottom: 16px;
    text-align: center;
}

.promotion-choices {
    display: flex;
    gap: 12px;
}

.promotion-btn {
    width: 80px;
    height: 80px;
    font-size: 48px;
    border: 2px solid var(--gray-100);
    background: white;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.promotion-btn:hover {
    background: var(--gray-50);
    border-color: var(--primary);
    transform: scale(1.1);
}

/* Controls Panel */
.controls-panel {
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    padding: 16px;
}

.controls-panel h3 {
    margin-bottom: 12px;
    font-size: 16px;
}

.controls-panel button {
    width: 100%;
    padding: 12px;
    margin-bottom: 8px;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.1);
    color: white;
}

.btn-secondary:hover:not(:disabled) {
    background: rgba(255, 255, 255, 0.2);
}

.btn-danger {
    background: var(--danger);
    color: white;
}

.btn-danger:hover:not(:disabled) {
    background: #dc2626;
}

.controls-panel button:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* Move History */
.moves-panel {
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: 12px;
    padding: 16px;
    flex: 1;
    overflow: hidden;
    display: flex;
    flex-direction: column;
}

.moves-panel h3 {
    margin-bottom: 12px;
    font-size: 16px;
}

.move-history {
    flex: 1;
    overflow-y: auto;
    background: rgba(0, 0, 0, 0.2);
    border-radius: 8px;
    padding: 12px;
}

.move-entry {
    display: flex;
    gap: 12px;
    padding: 6px 8px;
    margin-bottom: 4px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 4px;
    font-family: 'Courier New', monospace;
    font-size: 14px;
}

.move-number {
    color: var(--warning);
    font-weight: 700;
    min-width: 30px;
}

.move-text {
    flex: 1;
}

/* Lobby Panel */
.lobby-panel {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: white;
    color: var(--gray-800);
    padding: 40px;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.5);
    text-align: center;
    min-width: 400px;
    z-index: 50;
}

.lobby-panel h2 {
    color: var(--primary);
    margin-bottom: 24px;
    font-size: 28px;
}

.color-choice {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin: 24px 0;
}

.color-btn {
    padding: 16px 24px;
    border: 2px solid var(--gray-100);
    background: white;
    border-radius: 8px;
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.color-btn:hover {
    background: var(--primary);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

.color-btn.spectate {
    background: var(--gray-50);
}

.lobby-info {
    margin-top: 16px;
    font-size: 14px;
    color: var(--gray-800);
    font-style: italic;
}

/* Game Over Dialog */
.game-over-dialog {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: white;
    color: var(--gray-800);
    padding: 40px;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.5);
    text-align: center;
    min-width: 400px;
    z-index: 50;
}

.game-over-dialog h2 {
    font-size: 32px;
    margin-bottom: 16px;
}

.game-over-dialog .result {
    font-size: 24px;
    margin-bottom: 24px;
}

/* Mobile Responsive */
@media (max-width: 1200px) {
    .game-layout {
        flex-direction: column;
        padding: 10px;
    }

    .sidebar-left, .sidebar-right {
        width: 100%;
        flex-direction: row;
    }

    .chess-board {
        width: 90vw;
        height: 90vw;
        max-width: 500px;
        max-height: 500px;
    }

    .chess-square {
        font-size: 32px;
    }
}