/* ═══════════════════════════════════════════════════════════════
   CHESS ULTIMATE — Stylesheet
   Agents: Aesthetic, Palette, Layout, Responsive (UI Division)
   
   Glass-morphism dark theme, responsive layout,
   animations, VR-ready interface
   ═══════════════════════════════════════════════════════════════ */

:root {
    --bg-primary: #0a0a1a;
    --bg-secondary: #12122a;
    --bg-panel: rgba(15, 15, 35, 0.85);
    --bg-glass: rgba(20, 20, 50, 0.6);
    --text-primary: #e8e8f0;
    --text-secondary: #888899;
    --text-muted: #555566;
    --accent: #00ff88;
    --accent-dim: #00cc6a;
    --accent-glow: rgba(0, 255, 136, 0.3);
    --danger: #ff4444;
    --warning: #ffaa00;
    --info: #4488ff;
    --border: rgba(255, 255, 255, 0.08);
    --border-active: rgba(0, 255, 136, 0.4);
    --shadow: 0 4px 24px rgba(0, 0, 0, 0.5);
    --radius: 12px;
    --radius-sm: 8px;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html, body {
    height: 100%;
    overflow: hidden;
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    -webkit-font-smoothing: antialiased;
}

/* ═══ LAYOUT ═══ */
.game-container {
    display: flex;
    height: 100vh;
    width: 100vw;
    position: relative;
}

.canvas-container {
    flex: 1;
    position: relative;
    overflow: hidden;
}

.canvas-container canvas {
    display: block;
    width: 100% !important;
    height: 100% !important;
}

.side-panel {
    width: 340px;
    background: var(--bg-panel);
    border-left: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    backdrop-filter: blur(20px);
    z-index: 10;
}

/* ═══ TOP BAR ═══ */
.top-bar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 16px;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border);
    z-index: 20;
}

.top-bar-left {
    display: flex;
    align-items: center;
    gap: 12px;
}

.back-btn {
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 18px;
    cursor: pointer;
    padding: 6px 10px;
    border-radius: var(--radius-sm);
    transition: var(--transition);
}

.back-btn:hover {
    background: var(--bg-glass);
    color: var(--accent);
}

.game-title {
    font-size: 16px;
    font-weight: 700;
    letter-spacing: -0.3px;
}

.game-title .crown { color: var(--accent); }

.game-status {
    font-size: 12px;
    color: var(--text-secondary);
    padding: 3px 10px;
    background: var(--bg-glass);
    border-radius: 20px;
    border: 1px solid var(--border);
}

.top-bar-right {
    display: flex;
    gap: 8px;
}

.top-btn {
    background: var(--bg-glass);
    border: 1px solid var(--border);
    color: var(--text-primary);
    padding: 8px 12px;
    border-radius: var(--radius-sm);
    cursor: pointer;
    font-size: 14px;
    transition: var(--transition);
}

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

/* ═══ HUD OVERLAY ═══ */
#game-hud {
    position: absolute;
    inset: 0;
    pointer-events: none;
    z-index: 5;
}

#game-hud > * {
    pointer-events: auto;
}

.hud-top, .hud-bottom {
    position: absolute;
    left: 16px;
    right: 356px;
    padding: 0 8px;
}

.hud-top { top: 60px; }
.hud-bottom { bottom: 16px; }

.hud-left {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
}

.hud-center {
    position: absolute;
    right: 356px;
    top: 50%;
    transform: translateY(-50%);
}

/* ═══ PLAYER BAR ═══ */
.player-bar {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 14px;
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border-radius: var(--radius);
    border: 1px solid var(--border);
}

.player-avatar {
    font-size: 28px;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-secondary);
    border-radius: 50%;
}

.player-info {
    display: flex;
    flex-direction: column;
    flex: 1;
}

.player-name {
    font-weight: 600;
    font-size: 14px;
}

.player-elo {
    font-size: 11px;
    color: var(--text-secondary);
}

.captured-pieces {
    display: flex;
    gap: 1px;
    font-size: 16px;
    opacity: 0.7;
    flex-wrap: wrap;
    max-width: 120px;
}

.player-clock {
    font-family: 'JetBrains Mono', 'Courier New', monospace;
    font-size: 20px;
    font-weight: 700;
    padding: 4px 12px;
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
    min-width: 80px;
    text-align: center;
    letter-spacing: 1px;
}

.player-clock.clock-low {
    color: var(--warning);
}

.player-clock.clock-critical {
    color: var(--danger);
    animation: clockPulse 0.5s ease infinite;
}

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

/* ═══ EVAL BAR ═══ */
.eval-bar-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
}

.eval-bar {
    width: 16px;
    height: 200px;
    background: #333;
    border-radius: 8px;
    overflow: hidden;
    position: relative;
}

.eval-fill {
    position: absolute;
    bottom: 0;
    width: 100%;
    height: 50%;
    background: #fff;
    transition: height 0.5s ease;
    border-radius: 8px 8px 0 0;
}

.eval-value {
    font-size: 11px;
    color: var(--text-secondary);
    font-family: 'JetBrains Mono', monospace;
}

/* ═══ GAME CONTROLS ═══ */
.game-controls {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.ctrl-btn {
    width: 44px;
    height: 44px;
    border-radius: var(--radius);
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border);
    color: var(--text-primary);
    font-size: 16px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.ctrl-btn:hover {
    background: var(--accent);
    color: var(--bg-primary);
    border-color: var(--accent);
    transform: scale(1.05);
}

.ctrl-btn:active {
    transform: scale(0.95);
}

/* ═══ PANEL TABS ═══ */
.panel-tabs {
    display: flex;
    border-bottom: 1px solid var(--border);
    background: var(--bg-secondary);
}

.panel-tab {
    flex: 1;
    padding: 10px;
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 12px;
    cursor: pointer;
    transition: var(--transition);
    border-bottom: 2px solid transparent;
}

.panel-tab:hover {
    color: var(--text-primary);
    background: var(--bg-glass);
}

.panel-tab.active {
    color: var(--accent);
    border-bottom-color: var(--accent);
}

.panel-content {
    flex: 1;
    overflow: hidden;
    position: relative;
}

.panel-section {
    display: none;
    height: 100%;
    flex-direction: column;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    padding: 12px;
}

.panel-section.active {
    display: flex;
}

/* ═══ MOVE LIST ═══ */
.opening-name {
    font-size: 12px;
    color: var(--accent);
    padding: 6px 0;
    font-weight: 600;
}

.move-list {
    flex: 1;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    font-family: 'JetBrains Mono', monospace;
    font-size: 13px;
}

.move-row {
    display: flex;
    padding: 3px 0;
    gap: 4px;
}

.move-num {
    color: var(--text-muted);
    width: 30px;
    text-align: right;
    flex-shrink: 0;
}

.move-white, .move-black {
    flex: 1;
    padding: 2px 6px;
    border-radius: 4px;
    cursor: pointer;
    transition: var(--transition);
}

.move-white:hover, .move-black:hover {
    background: var(--bg-glass);
}

.last-move {
    background: var(--accent-glow);
    color: var(--accent);
}

.move-nav {
    display: flex;
    gap: 4px;
    padding: 8px 0;
    justify-content: center;
}

.nav-btn {
    width: 36px;
    height: 32px;
    border-radius: var(--radius-sm);
    background: var(--bg-glass);
    border: 1px solid var(--border);
    color: var(--text-primary);
    cursor: pointer;
    transition: var(--transition);
    font-size: 14px;
}

.nav-btn:hover {
    background: var(--accent);
    color: var(--bg-primary);
}

/* ═══ CHAT ═══ */
.chat-messages {
    flex: 1;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    display: flex;
    flex-direction: column;
    gap: 6px;
    padding-bottom: 8px;
}

.chat-msg {
    padding: 6px 10px;
    border-radius: var(--radius-sm);
    font-size: 13px;
    max-width: 90%;
}

.chat-msg.self {
    background: var(--accent-glow);
    align-self: flex-end;
    border: 1px solid var(--border-active);
}

.chat-msg.other {
    background: var(--bg-glass);
    align-self: flex-start;
    border: 1px solid var(--border);
}

.chat-msg.system {
    background: transparent;
    color: var(--text-muted);
    font-style: italic;
    align-self: center;
    font-size: 11px;
}

.chat-sender {
    font-weight: 600;
    font-size: 11px;
    color: var(--accent-dim);
    display: block;
}

.chat-input-row {
    display: flex;
    gap: 6px;
    padding-top: 8px;
}

#chat-input {
    flex: 1;
    background: var(--bg-glass);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    padding: 8px 12px;
    font-size: 13px;
    outline: none;
    transition: var(--transition);
}

#chat-input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px var(--accent-glow);
}

.chat-send {
    width: 36px;
    background: var(--accent);
    border: none;
    border-radius: var(--radius-sm);
    color: var(--bg-primary);
    font-size: 16px;
    cursor: pointer;
    transition: var(--transition);
}

.chat-send:hover { opacity: 0.8; }

/* ═══ VOICE CONTROLS ═══ */
.voice-controls {
    display: flex;
    gap: 8px;
    align-items: center;
    padding-top: 8px;
    border-top: 1px solid var(--border);
    margin-top: 8px;
}

.voice-btn {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--bg-glass);
    border: 1px solid var(--border);
    color: var(--text-primary);
    cursor: pointer;
    font-size: 14px;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.voice-btn:hover { border-color: var(--accent); }
.voice-btn.active {
    background: var(--accent);
    color: var(--bg-primary);
    border-color: var(--accent);
    box-shadow: 0 0 12px var(--accent-glow);
}

.voice-select {
    flex: 1;
    background: var(--bg-glass);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    padding: 6px 8px;
    font-size: 12px;
    outline: none;
}

/* ═══ ANALYSIS PANEL ═══ */
.analysis-eval {
    text-align: center;
    padding: 12px 0;
}

.eval-label {
    font-size: 11px;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.eval-big {
    font-size: 36px;
    font-weight: 700;
    font-family: 'JetBrains Mono', monospace;
    color: var(--accent);
}

.analysis-depth {
    font-size: 12px;
    color: var(--text-secondary);
    text-align: center;
    padding: 4px 0;
}

.analysis-pv {
    font-family: 'JetBrains Mono', monospace;
    font-size: 12px;
    color: var(--text-secondary);
    padding: 8px;
    background: var(--bg-glass);
    border-radius: var(--radius-sm);
    word-break: break-all;
    margin: 8px 0;
}

.analysis-controls {
    text-align: center;
    padding: 8px 0;
}

/* ═══ COACHING HINTS ═══ */
.hint-card {
    background: var(--bg-glass);
    border: 1px solid var(--border-active);
    border-radius: var(--radius);
    padding: 12px;
    margin-top: 12px;
}

.hint-icon {
    font-size: 24px;
    margin-bottom: 6px;
}

.hint-text {
    font-size: 13px;
    line-height: 1.5;
    color: var(--text-primary);
}

.hint-move {
    font-family: 'JetBrains Mono', monospace;
    font-size: 13px;
    color: var(--accent);
    margin-top: 6px;
}

/* ═══ SETTINGS ═══ */
.settings-group {
    padding: 10px 0;
    border-bottom: 1px solid var(--border);
}

.settings-group label {
    display: block;
    font-size: 12px;
    color: var(--text-secondary);
    margin-bottom: 6px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.setting-select {
    width: 100%;
    background: var(--bg-glass);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    padding: 8px 10px;
    font-size: 13px;
    outline: none;
}

.setting-range {
    width: 100%;
    accent-color: var(--accent);
}

.setting-check {
    accent-color: var(--accent);
    width: 18px;
    height: 18px;
}

.camera-presets {
    display: flex;
    gap: 6px;
    flex-wrap: wrap;
}

.preset-btn {
    padding: 6px 12px;
    background: var(--bg-glass);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 12px;
    cursor: pointer;
    transition: var(--transition);
}

.preset-btn:hover {
    background: var(--accent);
    color: var(--bg-primary);
}

/* ═══ GAME OVER MODAL ═══ */
.game-over-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    transition: opacity 0.3s ease;
    backdrop-filter: blur(8px);
}

.game-over-overlay.visible { opacity: 1; }

.game-over-modal {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px 40px;
    text-align: center;
    max-width: 400px;
    box-shadow: var(--shadow);
    transform: scale(0.9);
    transition: transform 0.3s ease;
}

.game-over-overlay.visible .game-over-modal {
    transform: scale(1);
}

.game-over-icon { font-size: 48px; margin-bottom: 12px; }
.game-over-title { font-size: 24px; font-weight: 700; margin-bottom: 8px; }
.game-over-reason { color: var(--text-secondary); font-size: 14px; margin-bottom: 12px; }
.game-over-elo { font-size: 18px; font-weight: 700; color: var(--accent); margin-bottom: 16px; }

.game-over-buttons {
    display: flex;
    gap: 8px;
    justify-content: center;
}

.go-btn {
    padding: 10px 20px;
    border-radius: var(--radius-sm);
    border: none;
    font-weight: 600;
    font-size: 14px;
    cursor: pointer;
    transition: var(--transition);
    background: var(--accent);
    color: var(--bg-primary);
}

.go-btn:hover { opacity: 0.85; transform: translateY(-1px); }
.go-btn.secondary {
    background: var(--bg-glass);
    color: var(--text-primary);
    border: 1px solid var(--border);
}

/* ═══ PROMOTION DIALOG ═══ */
.promotion-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1001;
    opacity: 0;
    transition: opacity 0.2s ease;
}

.promotion-overlay.visible { opacity: 1; }

.promotion-dialog {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
    text-align: center;
}

.promotion-dialog h3 {
    margin-bottom: 12px;
    font-size: 16px;
}

.promotion-pieces {
    display: flex;
    gap: 12px;
    justify-content: center;
}

.promo-btn {
    font-size: 36px;
    width: 56px;
    height: 56px;
    background: var(--bg-glass);
    border: 2px solid var(--border);
    border-radius: var(--radius);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
}

.promo-btn:hover {
    border-color: var(--accent);
    background: var(--accent-glow);
    transform: scale(1.1);
}

/* ═══ MAIN MENU ═══ */
.main-menu {
    position: absolute;
    inset: 0;
    background: rgba(10, 10, 26, 0.95);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    backdrop-filter: blur(20px);
}

.main-menu.hidden { display: none; }

.menu-container {
    text-align: center;
    max-width: 600px;
    width: 90%;
}

.menu-logo {
    font-size: 48px;
    font-weight: 900;
    margin-bottom: 4px;
    letter-spacing: -1px;
    background: linear-gradient(135deg, var(--accent), #4488ff);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.menu-subtitle {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 32px;
    letter-spacing: 3px;
    text-transform: uppercase;
}

.menu-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
    margin-bottom: 24px;
}

.menu-btn {
    padding: 16px 20px;
    background: var(--bg-glass);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text-primary);
    cursor: pointer;
    transition: var(--transition);
    text-align: left;
}

.menu-btn:hover {
    border-color: var(--accent);
    background: var(--accent-glow);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(0, 255, 136, 0.15);
}

.menu-btn-icon { font-size: 24px; margin-bottom: 6px; display: block; }
.menu-btn-title { font-weight: 700; font-size: 15px; display: block; }
.menu-btn-desc { font-size: 11px; color: var(--text-secondary); display: block; margin-top: 2px; }

.menu-footer {
    color: var(--text-muted);
    font-size: 11px;
}

/* ═══ AI SELECT ═══ */
.ai-select-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
    max-height: 50vh;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    padding: 4px;
}

.ai-card {
    padding: 10px 14px;
    background: var(--bg-glass);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    text-align: left;
}

.ai-card:hover {
    border-color: var(--accent);
    background: var(--accent-glow);
}

.ai-card.selected {
    border-color: var(--accent);
    background: var(--accent-glow);
    box-shadow: 0 0 12px var(--accent-glow);
}

.ai-card-icon { font-size: 20px; }
.ai-card-name { font-weight: 600; font-size: 13px; }
.ai-card-elo { font-size: 11px; color: var(--text-secondary); }
.ai-card-desc { font-size: 10px; color: var(--text-muted); margin-top: 2px; }

/* ═══ VR BUTTON ═══ */
.vr-button {
    position: absolute;
    bottom: 80px;
    right: 360px;
    padding: 12px 24px;
    background: var(--accent);
    color: var(--bg-primary);
    border: none;
    border-radius: var(--radius);
    font-weight: 700;
    font-size: 14px;
    cursor: pointer;
    z-index: 10;
    transition: var(--transition);
    letter-spacing: 1px;
}

.vr-button:hover { transform: scale(1.05); box-shadow: 0 0 20px var(--accent-glow); }

/* ═══ LOADING ═══ */
.loading-overlay {
    position: fixed;
    inset: 0;
    background: var(--bg-primary);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity 0.5s ease;
}

.loading-overlay.fade-out {
    opacity: 0;
    pointer-events: none;
}

.loading-spinner {
    width: 48px;
    height: 48px;
    border: 3px solid var(--border);
    border-top-color: var(--accent);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

.loading-text {
    margin-top: 16px;
    color: var(--text-secondary);
    font-size: 14px;
    animation: pulse 1.5s ease infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 0.6; }
    50% { opacity: 1; }
}

.loading-progress {
    width: 200px;
    height: 3px;
    background: var(--border);
    border-radius: 2px;
    margin-top: 12px;
    overflow: hidden;
}

.loading-bar {
    width: 0%;
    height: 100%;
    background: var(--accent);
    transition: width 0.3s ease;
}

/* ═══ RESPONSIVE ═══ */
@media (max-width: 900px) {
    .side-panel {
        position: fixed;
        right: -340px;
        top: 0;
        bottom: 0;
        transition: right 0.3s ease;
        z-index: 50;
    }

    .side-panel.open { right: 0; }

    .hud-top, .hud-bottom { right: 16px; }
    .hud-center { right: 16px; }

    .menu-grid { grid-template-columns: 1fr; }

    .vr-button { right: 16px; }

    .panel-toggle {
        display: flex !important;
    }
}

@media (min-width: 901px) {
    .panel-toggle { display: none !important; }
}

.panel-toggle {
    position: fixed;
    right: 16px;
    top: 70px;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border);
    color: var(--text-primary);
    font-size: 18px;
    cursor: pointer;
    z-index: 40;
    display: none;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.panel-toggle:hover {
    background: var(--accent);
    color: var(--bg-primary);
}

/* ═══ SCROLLBAR ═══ */
::-webkit-scrollbar { width: 4px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: var(--accent-dim); }

/* ═══ TOAST NOTIFICATIONS ═══ */
.toast-container {
    position: fixed;
    top: 16px;
    right: 16px;
    z-index: 2000;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.toast {
    padding: 10px 16px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 13px;
    max-width: 300px;
    box-shadow: var(--shadow);
    animation: slideIn 0.3s ease;
    backdrop-filter: blur(10px);
}

.toast.success { border-left: 3px solid var(--accent); }
.toast.error { border-left: 3px solid var(--danger); }
.toast.info { border-left: 3px solid var(--info); }

@keyframes slideIn {
    from { transform: translateX(100%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}