/* ========================================
   AI Chess - Premium Styles
   ======================================== */

:root {
    /* Colors */
    --bg-primary: #0f0f0f;
    --bg-secondary: #1a1a1a;
    --bg-tertiary: #242424;
    --bg-hover: #2a2a2a;

    --text-primary: #ffffff;
    --text-secondary: #a0a0a0;
    --text-muted: #666666;

    --accent-gold: #d4af37;
    --accent-gold-light: #f4d03f;
    --accent-gold-dark: #b8960c;
    --accent-green: #22c55e;
    --accent-red: #ef4444;

    --board-light: #f0d9b5;
    --board-dark: #b58863;
    --board-highlight: rgba(255, 255, 0, 0.4);
    --board-selected: rgba(0, 255, 0, 0.4);
    --board-possible: rgba(0, 150, 255, 0.4);
    --board-check: rgba(255, 0, 0, 0.5);

    --claude-color: #d97706;
    --sonnet-color: #8b5cf6;
    --gpt-color: #10a37f;
    --gpt5-color: #ff6b35;
    --gemini-color: #4285f4;
    --gemini3-color: #ea4335;
    --deepseek-color: #0066ff;
    --qwen-color: #7c3aed;
    --llama-color: #0ea5e9;

    --border-color: #333333;
    --shadow-color: rgba(0, 0, 0, 0.5);

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
    --transition-slow: 400ms ease;
}

/* ========================================
   Reset & Base
   ======================================== */

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

html, body {
    height: 100%;
    overflow: hidden;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.5;
}

/* ========================================
   App Container
   ======================================== */

.app-container {
    display: flex;
    flex-direction: column;
    height: 100vh;
    max-height: 100vh;
}

/* ========================================
   Header
   ======================================== */

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md) var(--spacing-xl);
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    flex-shrink: 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.logo-icon {
    font-size: 2rem;
    color: var(--accent-gold);
    text-shadow: 0 0 20px rgba(212, 175, 55, 0.5);
}

.logo-text {
    font-family: 'Playfair Display', serif;
    font-size: 1.5rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent-gold-light), var(--accent-gold));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Navigation */
.nav-links {
    display: flex;
    gap: var(--spacing-lg);
}

.nav-link {
    color: var(--text-muted);
    text-decoration: none;
    font-weight: 500;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
}

.nav-link:hover {
    color: var(--text-primary);
    background: var(--bg-hover);
}

.nav-link.active {
    color: var(--accent-gold);
    background: rgba(212, 175, 55, 0.1);
}

/* ========================================
   Buttons
   ======================================== */

.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    border: none;
    border-radius: var(--radius-md);
    font-family: inherit;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.btn-primary {
    background: linear-gradient(135deg, var(--accent-gold), var(--accent-gold-dark));
    color: var(--bg-primary);
}

.btn-primary:hover {
    background: linear-gradient(135deg, var(--accent-gold-light), var(--accent-gold));
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(212, 175, 55, 0.3);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--bg-hover);
    border-color: var(--accent-gold);
}

.btn-large {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 1rem;
}

.btn-icon {
    font-size: 1.1em;
}

/* ========================================
   Main Content
   ======================================== */

.main-content {
    display: flex;
    flex: 1;
    overflow: hidden;
    padding: var(--spacing-lg);
    gap: var(--spacing-lg);
}

/* ========================================
   Panels
   ======================================== */

.panel {
    width: 310px;
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    overflow-y: auto;
}

.panel-section {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
}

.panel-title {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

/* ========================================
   AI Selector
   ======================================== */

.ai-selector {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.current-ai-model {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
}

.current-ai-model .ai-model-name {
    font-weight: 500;
    color: var(--text-primary);
}

.ai-option {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-tertiary);
    border: 2px solid transparent;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.ai-option:hover {
    background: var(--bg-hover);
}

.ai-option.selected {
    border-color: var(--accent-gold);
    background: rgba(212, 175, 55, 0.1);
}

.ai-option[data-ai="claude"].selected {
    border-color: var(--claude-color);
    background: rgba(217, 119, 6, 0.1);
}

.ai-option[data-ai="gpt"].selected {
    border-color: var(--gpt-color);
    background: rgba(16, 163, 127, 0.1);
}

.ai-option[data-ai="sonnet"].selected {
    border-color: var(--sonnet-color);
    background: rgba(139, 92, 246, 0.1);
}

.ai-option[data-ai="gpt5"].selected {
    border-color: var(--gpt5-color);
    background: rgba(255, 107, 53, 0.1);
}

.ai-option[data-ai="gemini"].selected {
    border-color: var(--gemini-color);
    background: rgba(66, 133, 244, 0.1);
}

.ai-option[data-ai="deepseek-r1"].selected {
    border-color: var(--deepseek-color);
    background: rgba(0, 102, 255, 0.1);
}

.ai-option[data-ai="qwen-qwq"].selected {
    border-color: var(--qwen-color);
    background: rgba(124, 58, 237, 0.1);
}

.ai-option[data-ai="llama-4"].selected {
    border-color: var(--llama-color);
    background: rgba(14, 165, 233, 0.1);
}

.ai-option[data-ai="gemini3"].selected {
    border-color: var(--gemini3-color);
    background: rgba(234, 67, 53, 0.1);
}

.ai-icon {
    width: 36px;
    height: 36px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1rem;
    color: white;
}

.claude-icon {
    background: linear-gradient(135deg, #d97706, #b45309);
}

.sonnet-icon {
    background: linear-gradient(135deg, #8b5cf6, #7c3aed);
}

.gpt-icon {
    background: linear-gradient(135deg, #10a37f, #0d8a6a);
}

.gpt5-icon {
    background: linear-gradient(135deg, #ff6b35, #e85a24);
}

.gemini-icon {
    background: linear-gradient(135deg, #4285f4, #34a853, #fbbc05, #ea4335);
}

.deepseek-icon {
    background: linear-gradient(135deg, #0066ff, #0044cc);
}

.qwen-icon {
    background: linear-gradient(135deg, #7c3aed, #5b21b6);
}

.llama-icon {
    background: linear-gradient(135deg, #0ea5e9, #0284c7);
}

.gemini3-icon {
    background: linear-gradient(135deg, #ea4335, #c62828);
}

.ai-name {
    flex: 1;
    font-weight: 500;
    color: var(--text-primary);
    text-align: left;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.ai-badge {
    font-size: 0.625rem;
    padding: 2px 6px;
    background: var(--bg-primary);
    border-radius: var(--radius-sm);
    color: var(--text-muted);
}

/* AI Selector locked state (during active game) */
.ai-selector.game-active .ai-option.locked {
    opacity: 0.4;
    pointer-events: none;
    cursor: not-allowed;
}

.ai-selector.game-active .ai-option.selected {
    cursor: default;
    pointer-events: none;
}

.ai-selector.game-active .ai-option.selected::after {
    content: "Playing";
    font-size: 0.6rem;
    padding: 2px 5px;
    background: var(--accent-green);
    border-radius: var(--radius-sm);
    color: white;
    margin-left: auto;
    flex-shrink: 0;
    white-space: nowrap;
}

/* ========================================
   Game Status
   ======================================== */

.game-status {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.status-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-sm);
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
}

.status-label {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.status-value {
    font-weight: 600;
    font-size: 0.875rem;
}

.turn-white {
    color: #ffffff;
}

.turn-black {
    color: var(--text-secondary);
}

.your-turn {
    color: var(--accent-green);
}

.ai-turn {
    color: var(--accent-gold);
}

/* ========================================
   Captured Pieces
   ======================================== */

.captured-pieces {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.captured-row {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.captured-label {
    font-size: 0.75rem;
    color: var(--text-secondary);
    width: 50px;
}

.captured-list {
    display: flex;
    flex-wrap: wrap;
    gap: 2px;
    font-size: 1.25rem;
    min-height: 28px;
}

/* ========================================
   Chess Board
   ======================================== */

.board-container {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: relative;
}

.board-frame {
    background: linear-gradient(135deg, #2a2420, #1a1615);
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    box-shadow:
        0 20px 60px rgba(0, 0, 0, 0.5),
        inset 0 1px 0 rgba(255, 255, 255, 0.05);
}

.board-frame {
    --square-size: 75px;
}

.board-labels {
    display: flex;
    justify-content: space-around;
    padding: 0 var(--spacing-xs);
}

.board-labels span {
    width: var(--square-size);
    text-align: center;
    font-size: 0.9rem;
    color: var(--text-muted);
    font-weight: 500;
}

.board-labels.top, .board-labels.bottom {
    padding: var(--spacing-xs) 28px;
}

.board-labels.left, .board-labels.right {
    flex-direction: column;
    padding: 0;
}

.board-labels.left span, .board-labels.right span {
    height: var(--square-size);
    width: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.board-with-numbers {
    display: flex;
    align-items: center;
}

.chess-board {
    display: grid;
    grid-template-columns: repeat(8, var(--square-size));
    grid-template-rows: repeat(8, var(--square-size));
    border: 2px solid #3a3530;
    border-radius: var(--radius-sm);
    overflow: hidden;
    box-shadow: inset 0 0 20px rgba(0, 0, 0, 0.3);
}

.square {
    width: var(--square-size);
    height: var(--square-size);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: calc(var(--square-size) * 0.6);
    cursor: pointer;
    position: relative;
    transition: background-color var(--transition-fast);
    user-select: none;
}

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

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

.square.selected {
    background: var(--board-selected) !important;
}

.square.possible-move::after {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    background: var(--board-possible);
    border-radius: 50%;
}

.square.possible-capture {
    background: rgba(255, 100, 100, 0.4) !important;
}

.square.last-move {
    background: var(--board-highlight) !important;
}

.square.check {
    background: var(--board-check) !important;
    animation: pulse-check 1s ease-in-out infinite;
}

@keyframes pulse-check {
    0%, 100% { box-shadow: inset 0 0 20px rgba(255, 0, 0, 0.5); }
    50% { box-shadow: inset 0 0 30px rgba(255, 0, 0, 0.8); }
}

.piece {
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
    transition: transform var(--transition-fast);
    cursor: grab;
}

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

.piece.white {
    color: #ffffff;
    filter: drop-shadow(1px 1px 2px rgba(0, 0, 0, 0.5));
}

.piece.black {
    color: #1a1a1a;
    filter: drop-shadow(1px 1px 2px rgba(255, 255, 255, 0.2));
}

/* ========================================
   AI Thinking Indicator
   ======================================== */

.ai-thinking {
    position: absolute;
    bottom: var(--spacing-lg);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md) var(--spacing-xl);
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
}

.ai-thinking.hidden {
    display: none;
}

.thinking-spinner {
    width: 24px;
    height: 24px;
    border: 3px solid var(--border-color);
    border-top-color: var(--accent-gold);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* ========================================
   Move History
   ======================================== */

.move-history {
    max-height: 300px;
    overflow-y: auto;
    font-family: 'Courier New', monospace;
    font-size: 0.875rem;
}

.move-placeholder {
    color: var(--text-muted);
    font-style: italic;
    text-align: center;
    padding: var(--spacing-lg);
}

/* Move history header */
.move-header {
    display: grid;
    grid-template-columns: 28px 1fr 1fr;
    gap: var(--spacing-sm);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-bottom: 1px solid var(--border-color);
    margin-bottom: var(--spacing-xs);
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    color: var(--text-muted);
}

.move-header .header-first {
    color: var(--accent-green);
}

.move-header .header-second {
    color: var(--accent-gold);
}

/* Move row - side by side */
.move-row {
    display: grid;
    grid-template-columns: 28px 1fr 1fr;
    gap: var(--spacing-sm);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
}

.move-row:hover {
    background: var(--bg-tertiary);
}

.move-row .move-num {
    color: var(--text-muted);
    font-size: 0.75rem;
}

.move-row .move-white,
.move-row .move-black {
    font-family: 'SF Mono', 'Monaco', 'Consolas', monospace;
    font-weight: 500;
}

.move-row .move-white {
    color: var(--text-primary);
}

.move-row .move-black {
    color: var(--text-secondary);
}

/* ========================================
   AI Message
   ======================================== */

.ai-message {
    padding: var(--spacing-md);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.6;
    max-height: 200px;
    overflow-y: auto;
}

.ai-message p {
    margin: 0;
}

/* ========================================
   Modal
   ======================================== */

.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(8px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    animation: fadeIn var(--transition-normal);
}

.modal.hidden {
    display: none;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

.modal-content {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-xl);
    padding: var(--spacing-lg);
    max-width: 480px;
    width: 95%;
    max-height: 85vh;
    overflow-y: auto;
    animation: slideUp var(--transition-normal);
    margin: var(--spacing-md);
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.modal-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.modal-header h2 {
    font-family: 'Playfair Display', serif;
    font-size: 2rem;
    color: var(--accent-gold);
    margin-bottom: var(--spacing-sm);
}

.modal-header p {
    color: var(--text-secondary);
}

.modal-body {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.modal-footer {
    margin-top: var(--spacing-xl);
    text-align: center;
}

/* Color Selection */
.color-selection h3, .ai-selection-modal h3 {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    text-align: center;
}

.color-options {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
}

.color-option {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-lg);
    background: var(--bg-tertiary);
    border: 2px solid transparent;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-fast);
    min-width: 140px;
}

.color-option:hover {
    background: var(--bg-hover);
}

.color-option.selected {
    border-color: var(--accent-gold);
    background: rgba(212, 175, 55, 0.1);
}

.piece-preview {
    font-size: 3rem;
}

.piece-preview.white {
    color: #ffffff;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.5);
}

.piece-preview.black {
    color: #1a1a1a;
    text-shadow: 1px 1px 2px rgba(255, 255, 255, 0.3);
}

.color-option span {
    font-weight: 500;
    color: var(--text-primary);
}

.color-option small {
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* AI Selection Modal */
.ai-options-modal {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
    max-height: 220px;
    overflow-y: auto;
    padding-right: var(--spacing-xs);
}

.ai-option-modal {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: 8px 10px;
    background: var(--bg-tertiary);
    border: 2px solid transparent;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
    text-align: left;
    font-size: 0.8rem;
}

.ai-option-modal:hover {
    background: var(--bg-hover);
}

.ai-option-modal.selected {
    border-color: var(--accent-gold);
    background: rgba(212, 175, 55, 0.1);
}

.ai-option-modal[data-ai="claude"].selected {
    border-color: var(--claude-color);
    background: rgba(217, 119, 6, 0.1);
}

.ai-option-modal[data-ai="gpt"].selected {
    border-color: var(--gpt-color);
    background: rgba(16, 163, 127, 0.1);
}

.ai-option-modal[data-ai="gemini"].selected {
    border-color: var(--gemini-color);
    background: rgba(66, 133, 244, 0.1);
}

.ai-option-modal[data-ai="deepseek-r1"].selected {
    border-color: var(--deepseek-color);
    background: rgba(0, 102, 255, 0.1);
}

.ai-option-modal[data-ai="qwen-qwq"].selected {
    border-color: var(--qwen-color);
    background: rgba(124, 58, 237, 0.1);
}

.ai-option-modal[data-ai="llama-4"].selected {
    border-color: var(--llama-color);
    background: rgba(14, 165, 233, 0.1);
}

.ai-option-modal[data-ai="sonnet"].selected {
    border-color: var(--sonnet-color);
    background: rgba(139, 92, 246, 0.1);
}

.ai-option-modal[data-ai="gpt5"].selected {
    border-color: var(--gpt5-color);
    background: rgba(255, 107, 53, 0.1);
}

.ai-option-modal[data-ai="gemini3"].selected {
    border-color: var(--gemini3-color);
    background: rgba(234, 67, 53, 0.1);
}

.ai-info {
    display: flex;
    flex-direction: column;
}

.ai-info .ai-name {
    font-weight: 600;
    color: var(--text-primary);
}

.ai-info .ai-desc {
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* Game Over Modal */
.modal-content.game-over .modal-header h2 {
    font-size: 2.5rem;
}

/* Small Modal (Leave Game Confirmation) */
.modal-content.modal-small {
    max-width: 400px;
}

.modal-content.modal-small .modal-header h2 {
    font-size: 1.5rem;
    color: var(--accent-red);
}

.modal-content.modal-small .modal-header p {
    margin-top: var(--spacing-sm);
}

.modal-footer-buttons {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
}

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

.btn-danger:hover {
    background: #dc2626;
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(239, 68, 68, 0.3);
}

/* Move history player/AI styling */
.move-white.player-move,
.move-black.player-move {
    color: var(--accent-green);
    font-weight: 500;
}

.move-white.ai-move,
.move-black.ai-move {
    color: var(--accent-gold);
    font-weight: 500;
}

/* Game Action Buttons */
.game-actions {
    padding: var(--spacing-sm) 0;
}

.action-buttons {
    display: flex;
    gap: var(--spacing-sm);
}

.btn-small {
    padding: var(--spacing-xs) var(--spacing-sm);
    font-size: 0.8rem;
    flex: 1;
}

.game-actions.hidden {
    display: none;
}

/* ========================================
   Scrollbar
   ======================================== */

::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb {
    background: var(--border-color);
    border-radius: var(--radius-sm);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

/* ========================================
   Responsive
   ======================================== */

@media (max-width: 1600px) {
    .panel {
        width: 240px;
    }

    .chess-board {
        grid-template-columns: repeat(8, 85px);
        grid-template-rows: repeat(8, 85px);
    }

    .square {
        width: 85px;
        height: 85px;
        font-size: 3.4rem;
    }

    .board-labels span {
        width: 85px;
    }

    .board-labels.left span, .board-labels.right span {
        height: 85px;
    }
}

@media (max-width: 1400px) {
    .panel {
        width: 220px;
    }

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

    .square {
        width: 70px;
        height: 70px;
        font-size: 2.8rem;
    }

    .board-labels span {
        width: 70px;
    }

    .board-labels.left span, .board-labels.right span {
        height: 70px;
    }
}

@media (max-width: 1200px) {
    .panel {
        width: 200px;
    }

    .chess-board {
        grid-template-columns: repeat(8, 60px);
        grid-template-rows: repeat(8, 60px);
    }

    .square {
        width: 60px;
        height: 60px;
        font-size: 2.4rem;
    }

    .board-labels span {
        width: 60px;
    }

    .board-labels.left span, .board-labels.right span {
        height: 60px;
    }
}

@media (max-width: 1000px) {
    .main-content {
        flex-direction: column;
        align-items: center;
    }

    .panel {
        width: 100%;
        max-width: 500px;
    }

    .left-panel {
        order: 2;
    }

    .board-container {
        order: 1;
    }

    .right-panel {
        order: 3;
    }

    .chess-board {
        grid-template-columns: repeat(8, 50px);
        grid-template-rows: repeat(8, 50px);
    }

    .square {
        width: 50px;
        height: 50px;
        font-size: 2rem;
    }

    .board-labels span {
        width: 50px;
        font-size: 0.75rem;
    }

    .board-labels.left span, .board-labels.right span {
        height: 50px;
        width: 20px;
    }

    .board-labels.top, .board-labels.bottom {
        padding: var(--spacing-xs) 20px;
    }
}

/* Tablet Portrait */
@media (max-width: 768px) {
    html, body {
        overflow-x: hidden;
        overflow-y: auto;
    }

    .app-container {
        height: auto;
        min-height: 100vh;
    }

    .header {
        padding: var(--spacing-sm) var(--spacing-md);
        flex-wrap: wrap;
        gap: var(--spacing-sm);
    }

    .logo-text {
        font-size: 1.2rem;
    }

    .logo-icon {
        font-size: 1.5rem;
    }

    .nav-links {
        gap: var(--spacing-sm);
    }

    .nav-link {
        padding: var(--spacing-xs) var(--spacing-sm);
        font-size: 0.875rem;
    }

    .main-content {
        padding: var(--spacing-sm);
        gap: var(--spacing-sm);
        overflow-y: auto;
    }

    .board-frame {
        padding: var(--spacing-sm);
    }

    .chess-board {
        grid-template-columns: repeat(8, 42px);
        grid-template-rows: repeat(8, 42px);
    }

    .square {
        width: 42px;
        height: 42px;
        font-size: 1.7rem;
    }

    .board-labels span {
        width: 42px;
        font-size: 0.65rem;
    }

    .board-labels.left span, .board-labels.right span {
        height: 42px;
        width: 16px;
    }

    .board-labels.top, .board-labels.bottom {
        padding: 2px 16px;
    }

    .panel-section {
        padding: var(--spacing-sm);
    }

    .panel-title {
        font-size: 0.7rem;
        margin-bottom: var(--spacing-sm);
    }

    .ai-thinking {
        bottom: var(--spacing-sm);
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: 0.875rem;
    }
}

/* Mobile */
@media (max-width: 480px) {
    .header {
        padding: var(--spacing-xs) var(--spacing-sm);
    }

    .logo-text {
        font-size: 1rem;
    }

    .logo-icon {
        font-size: 1.3rem;
    }

    .header-actions .btn {
        padding: var(--spacing-xs) var(--spacing-sm);
        font-size: 0.75rem;
    }

    .header-actions .btn-icon {
        display: none;
    }

    .nav-link {
        padding: var(--spacing-xs);
        font-size: 0.8rem;
    }

    .main-content {
        padding: var(--spacing-xs);
        gap: var(--spacing-xs);
    }

    .board-frame {
        padding: 6px;
    }

    /* Dynamic board sizing based on viewport width */
    .chess-board {
        --mobile-square: calc((100vw - 60px) / 8);
        grid-template-columns: repeat(8, var(--mobile-square));
        grid-template-rows: repeat(8, var(--mobile-square));
    }

    .square {
        width: var(--mobile-square);
        height: var(--mobile-square);
        font-size: calc(var(--mobile-square) * 0.65);
    }

    .board-labels span {
        width: var(--mobile-square);
        font-size: 0.6rem;
    }

    .board-labels.left span, .board-labels.right span {
        height: var(--mobile-square);
        width: 14px;
    }

    .board-labels.top, .board-labels.bottom {
        padding: 2px 14px;
    }

    .panel {
        max-width: 100%;
    }

    .panel-section {
        padding: var(--spacing-xs);
    }

    .panel-title {
        font-size: 0.65rem;
    }

    .ai-option {
        padding: var(--spacing-xs) var(--spacing-sm);
        gap: var(--spacing-sm);
    }

    .ai-icon {
        width: 28px;
        height: 28px;
        font-size: 0.8rem;
    }

    .ai-name {
        font-size: 0.85rem;
    }

    .ai-badge {
        font-size: 0.55rem;
        padding: 1px 4px;
    }

    .status-item {
        padding: var(--spacing-xs);
    }

    .status-label {
        font-size: 0.65rem;
    }

    .status-value {
        font-size: 0.8rem;
    }

    .captured-list {
        font-size: 1rem;
        min-height: 22px;
    }

    .captured-label {
        font-size: 0.65rem;
        width: 40px;
    }

    .move-history {
        max-height: 150px;
        font-size: 0.75rem;
    }

    .move-row {
        padding: 2px var(--spacing-xs);
        font-size: 0.75rem;
    }

    .ai-message {
        font-size: 0.8rem;
        max-height: 100px;
        padding: var(--spacing-sm);
    }

    .ai-thinking {
        padding: var(--spacing-xs) var(--spacing-sm);
        font-size: 0.8rem;
        gap: var(--spacing-sm);
    }

    .thinking-spinner {
        width: 18px;
        height: 18px;
    }

    /* Modal adjustments for mobile */
    .modal {
        align-items: flex-start;
        padding: var(--spacing-sm);
        overflow-y: auto;
    }

    .modal-content {
        margin: var(--spacing-sm) auto;
        padding: var(--spacing-sm);
        max-height: none;
        width: 100%;
    }

    .modal-header {
        margin-bottom: var(--spacing-sm);
    }

    .modal-header h2 {
        font-size: 1.3rem;
        margin-bottom: 2px;
    }

    .modal-header p {
        font-size: 0.8rem;
    }

    .modal-body {
        gap: var(--spacing-sm);
    }

    .color-selection h3,
    .ai-selection-modal h3 {
        font-size: 0.75rem;
        margin-bottom: var(--spacing-xs);
    }

    .color-options {
        flex-direction: row;
        gap: var(--spacing-xs);
    }

    .color-option {
        min-width: auto;
        padding: var(--spacing-sm);
        flex-direction: column;
        gap: var(--spacing-xs);
        flex: 1;
    }

    .piece-preview {
        font-size: 1.8rem;
    }

    .color-option span {
        font-size: 0.8rem;
    }

    .color-option small {
        font-size: 0.65rem;
    }

    .ai-options-modal {
        max-height: 120px;
    }

    .ai-option-modal {
        padding: 5px 8px;
        font-size: 0.7rem;
    }

    .ai-option-modal .ai-icon {
        width: 22px;
        height: 22px;
        font-size: 0.65rem;
    }

    .ai-info .ai-name {
        font-size: 0.75rem;
    }

    .ai-info .ai-desc {
        font-size: 0.6rem;
    }

    .modal-footer {
        margin-top: var(--spacing-sm);
    }

    .btn-large {
        padding: var(--spacing-sm) var(--spacing-lg);
        font-size: 0.9rem;
        width: 100%;
    }

    .action-buttons {
        flex-direction: column;
    }

    .btn-small {
        font-size: 0.75rem;
    }

    /* Game over and other modals */
    .modal-content.game-over .modal-header h2 {
        font-size: 1.5rem;
    }

    .modal-footer-buttons {
        flex-direction: column;
        gap: var(--spacing-xs);
    }

    .modal-footer-buttons .btn {
        width: 100%;
    }
}

/* Very small screens */
@media (max-width: 360px) {
    .chess-board {
        --mobile-square: calc((100vw - 50px) / 8);
    }

    .board-labels.left span, .board-labels.right span {
        width: 12px;
    }

    .board-labels.top, .board-labels.bottom {
        padding: 2px 12px;
    }

    .board-labels span {
        font-size: 0.5rem;
    }

    .header {
        justify-content: center;
    }

    .nav-links {
        order: 3;
        width: 100%;
        justify-content: center;
    }

    /* Modal for very small screens */
    .modal-content {
        padding: var(--spacing-xs);
    }

    .modal-header h2 {
        font-size: 1.1rem;
    }

    .piece-preview {
        font-size: 1.5rem;
    }

    .color-option {
        padding: var(--spacing-xs);
    }

    .ai-options-modal {
        max-height: 100px;
    }

    .ai-option-modal {
        padding: 4px 6px;
    }

    .ai-option-modal .ai-icon {
        width: 18px;
        height: 18px;
        font-size: 0.55rem;
    }
}

/* ========================================
   Leaderboard Modal
   ======================================== */

.leaderboard-modal {
    max-width: 800px;
    width: 95%;
}

.leaderboard-modal .modal-header {
    position: relative;
}

.modal-close {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.5rem;
    cursor: pointer;
    padding: var(--spacing-xs);
    line-height: 1;
    transition: color var(--transition-fast);
}

.modal-close:hover {
    color: var(--text-primary);
}

.leaderboard-content {
    margin-bottom: var(--spacing-xl);
}

.leaderboard-table {
    width: 100%;
    border-collapse: collapse;
}

.leaderboard-table th,
.leaderboard-table td {
    padding: var(--spacing-md);
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.leaderboard-table th {
    font-weight: 600;
    color: var(--text-muted);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.leaderboard-table tr:hover {
    background: var(--bg-hover);
}

.rank-cell {
    font-size: 1.25rem;
    font-weight: 700;
    width: 50px;
    text-align: center;
}

.rank-cell.gold { color: #FFD700; }
.rank-cell.silver { color: #C0C0C0; }
.rank-cell.bronze { color: #CD7F32; }

.model-cell {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.model-icon {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.875rem;
    color: white;
}

.model-icon.claude { background: var(--claude-color); }
.model-icon.gpt { background: var(--gpt-color); }
.model-icon.gemini { background: var(--gemini-color); }

.model-info-cell {
    display: flex;
    flex-direction: column;
}

.model-name {
    font-weight: 600;
    color: var(--text-primary);
}

.model-provider {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.stat-cell {
    text-align: center;
}

.stat-value {
    font-weight: 600;
    font-size: 1.125rem;
    color: var(--text-primary);
}

.stat-label {
    font-size: 0.625rem;
    color: var(--text-muted);
    text-transform: uppercase;
}

.win-rate {
    font-weight: 700;
    font-size: 1.25rem;
}

.win-rate.high { color: #22c55e; }
.win-rate.medium { color: #f59e0b; }
.win-rate.low { color: #ef4444; }

/* Recent Games */
.recent-games-section h3 {
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
    font-size: 1rem;
}

.recent-games-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
    max-height: 250px;
    overflow-y: auto;
}

.recent-game-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    gap: var(--spacing-md);
}

.game-ai-badge {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-weight: 500;
}

.game-ai-badge .model-icon {
    width: 24px;
    height: 24px;
    font-size: 0.625rem;
}

.game-result {
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
    font-weight: 600;
}

.game-result.ai-win {
    background: rgba(239, 68, 68, 0.2);
    color: #ef4444;
}

.game-result.player-win {
    background: rgba(34, 197, 94, 0.2);
    color: #22c55e;
}

.game-result.draw {
    background: rgba(156, 163, 175, 0.2);
    color: #9ca3af;
}

.game-stats {
    display: flex;
    gap: var(--spacing-lg);
    font-size: 0.75rem;
    color: var(--text-muted);
}

.game-time {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.loading-spinner {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--text-muted);
}

.total-games-badge {
    text-align: center;
    padding: var(--spacing-md);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-lg);
}

.total-games-badge .count {
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-gold);
}

.total-games-badge .label {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-transform: uppercase;
}