/* ============================================
   MusicTree — Premium Dark UI
   ============================================ */

:root {
    /* Colors */
    --bg-primary: #0a0a0f;
    --bg-secondary: #111118;
    --bg-tertiary: #1a1a24;
    --bg-elevated: #1e1e2a;
    --bg-glass: rgba(16, 16, 28, 0.65);

    --text-primary: #e8e8f0;
    --text-secondary: #9898b0;
    --text-tertiary: #606078;
    --text-accent: #c4b5fd;

    --accent-hue: 270;
    --accent: hsl(var(--accent-hue), 85%, 68%);
    --accent-dim: hsl(var(--accent-hue), 60%, 45%);
    --accent-glow: hsl(var(--accent-hue), 90%, 70%);
    --accent-bg: hsla(var(--accent-hue), 80%, 60%, 0.08);
    --accent-bg-hover: hsla(var(--accent-hue), 80%, 60%, 0.15);

    --cyan: #06b6d4;
    --cyan-dim: #0891b2;
    --emerald: #34d399;
    --rose: #fb7185;

    --border: rgba(255, 255, 255, 0.06);
    --border-hover: rgba(255, 255, 255, 0.12);
    --border-focus: hsla(var(--accent-hue), 80%, 60%, 0.4);

    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 20px hsla(var(--accent-hue), 80%, 60%, 0.15);

    --sidebar-width: 300px;
    --header-height: 56px;
    --transport-height: 64px;

    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
}

body.light-theme {
    --bg-primary: #f8f9fa;
    --bg-secondary: #ffffff;
    --bg-tertiary: #e9ecef;
    --bg-elevated: #dee2e6;
    --bg-glass: rgba(248, 249, 250, 0.85);

    --text-primary: #212529;
    --text-secondary: #495057;
    --text-tertiary: #adb5bd;
    --text-accent: #6d28d9;

    --accent-dim: hsl(var(--accent-hue), 75%, 55%);
    --accent-bg: hsla(var(--accent-hue), 80%, 60%, 0.12);
    --accent-bg-hover: hsla(var(--accent-hue), 80%, 60%, 0.2);

    --border: rgba(0, 0, 0, 0.08);
    --border-hover: rgba(0, 0, 0, 0.15);

    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.15);
}

body.light-theme .ambient-orb {
    opacity: 0.1;
}

/* Cyberpunk Neon Theme */
body.cyberpunk-theme {
    --bg-primary: #050510;
    --bg-secondary: #0a0a20;
    --bg-tertiary: #101030;
    --bg-elevated: #151540;
    --bg-glass: rgba(5, 5, 20, 0.85);

    --text-primary: #00ffff;
    --text-secondary: #ff00ff;
    --text-tertiary: #39FF14;
    --text-accent: #FFFF00;

    --accent-dim: #ff00ff;
    --accent-bg: rgba(255, 0, 255, 0.1);
    --border: rgba(0, 255, 255, 0.2);
    --border-hover: rgba(121, 255, 121, 0.5);
    
    --shadow-glow: 0 0 15px rgba(0, 255, 255, 0.3);
}

body.cyberpunk-theme .ambient-orb {
    opacity: 0.25;
    filter: blur(150px) saturate(2);
}

/* Midnight Black Theme */
body.midnight-theme {
    --bg-primary: #000000;
    --bg-secondary: #050505;
    --bg-tertiary: #0a0a0a;
    --bg-elevated: #0f0f0f;
    --bg-glass: rgba(0, 0, 0, 0.85);

    --text-primary: #ffffff;
    --text-secondary: #666666;
    --text-tertiary: #333333;
    
    --border: rgba(255, 255, 255, 0.08);
    --border-hover: rgba(255, 255, 255, 0.15);
}

body.midnight-theme .ambient-bg {
    display: none;
}

/* Arctic Nord Theme */
body.nord-theme {
    --bg-primary: #2e3440;
    --bg-secondary: #3b4252;
    --bg-tertiary: #434c5e;
    --bg-elevated: #4c566a;
    --bg-glass: rgba(46, 52, 64, 0.9);

    --text-primary: #eceff4;
    --text-secondary: #d8dee9;
    --text-tertiary: #aebfd5;
    --text-accent: #88c0d0;

    --accent-dim: #81a1c1;
    --accent-bg: rgba(136, 192, 208, 0.1);
    --border: rgba(236, 239, 244, 0.1);
}

body.nord-theme .ambient-orb {
    opacity: 0.15;
    background: #88c0d0;
}

/* Royal Gold Theme */
body.golden-theme {
    --bg-primary: #0c0b0a;
    --bg-secondary: #141210;
    --bg-tertiary: #1c1916;
    --bg-elevated: #24211d;
    --bg-glass: rgba(12, 11, 10, 0.92);

    --text-primary: #f5f1e8;
    --text-secondary: #b0a080;
    --text-tertiary: #605040;
    --text-accent: #ffd700;

    --accent-dim: #c5a059;
    --accent-bg: rgba(255, 215, 0, 0.05);
    --border: rgba(197, 160, 89, 0.15);
}

body.golden-theme .ambient-orb {
    opacity: 0.15;
    background: #ffd700;
}

/* Sakura Light Theme */
body.sakura-theme {
    --bg-primary: #fff5f8;
    --bg-secondary: #ffffff;
    --bg-tertiary: #ffe4ef;
    --bg-elevated: #ffd1e3;
    --bg-glass: rgba(255, 245, 248, 0.85);

    --text-primary: #5c2f40;
    --text-secondary: #a36b81;
    --text-tertiary: #d6abbc;
    --text-accent: #ff69b4;

    --accent-dim: #ff8ab4;
    --accent-bg: rgba(255, 105, 180, 0.1);
    --border: rgba(255, 105, 180, 0.12);
}

body.sakura-theme .ambient-orb {
    opacity: 0.2;
    background: #ff69b4;
}

/* ============================================
   Reset & Base
   ============================================ */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 14px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    overflow: hidden;
    height: 100vh;
    width: 100vw;
}

/* ============================================
   Ambient Background
   ============================================ */
.ambient-bg {
    position: fixed;
    inset: 0;
    z-index: 0;
    pointer-events: none;
    overflow: hidden;
}

.ambient-orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(100px);
    opacity: 0.2;
    animation: float 20s ease-in-out infinite;
}

.orb-1 {
    width: 600px;
    height: 600px;
    background: hsl(var(--accent-hue), 80%, 50%);
    top: -200px;
    right: -100px;
    animation-delay: 0s;
}

.orb-2 {
    width: 500px;
    height: 500px;
    background: var(--cyan);
    bottom: -150px;
    left: -100px;
    animation-delay: -7s;
}

.orb-3 {
    width: 400px;
    height: 400px;
    background: var(--emerald);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation-delay: -14s;
    opacity: 0.08;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) scale(1); }
    25% { transform: translate(30px, -40px) scale(1.05); }
    50% { transform: translate(-20px, 20px) scale(0.95); }
    75% { transform: translate(40px, 30px) scale(1.02); }
}

/* ============================================
   Scrollbar
   ============================================ */
::-webkit-scrollbar {
    width: 6px;
}
::-webkit-scrollbar-track {
    background: transparent;
}
::-webkit-scrollbar-thumb {
    background: var(--border-hover);
    border-radius: 10px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--text-tertiary);
}

.license-list {
    margin: 10px 0 0 18px;
    font-size: 0.85rem;
    color: var(--text-secondary);
}
.license-list li {
    margin-bottom: 4px;
}
.license-list a {
    color: var(--accent);
    text-decoration: none;
}
.license-list a:hover {
    text-decoration: underline;
}

/* ============================================
   Header
   ============================================ */
#app-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 20px;
    background: var(--bg-glass);
    backdrop-filter: blur(30px) saturate(1.8);
    -webkit-backdrop-filter: blur(30px) saturate(1.8);
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    z-index: 100;
}

.header-left, .header-right {
    display: flex;
    align-items: center;
    gap: 8px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-icon {
    width: 28px;
    height: 28px;
}

.logo-text {
    font-size: 1.2rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--accent), var(--cyan));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
}

.tab-bar {
    display: flex;
    background: var(--bg-tertiary);
    border-radius: var(--radius-lg);
    padding: 3px;
    gap: 2px;
    border: 1px solid var(--border);
}

.tab {
    padding: 6px 18px;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-family: inherit;
    font-size: 0.85rem;
    font-weight: 500;
    border-radius: calc(var(--radius-lg) - 3px);
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

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

.tab.active {
    color: var(--text-primary);
    background: var(--accent-dim);
    box-shadow: var(--shadow-sm);
}

.icon-btn {
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--border);
    background: transparent;
    color: var(--text-secondary);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
}

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

/* ============================================
   Main Layout
   ============================================ */
#app-main {
    display: flex;
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    bottom: var(--transport-height);
}

/* ============================================
   Sidebar
   ============================================ */
.sidebar {
    width: var(--sidebar-width);
    min-width: var(--sidebar-width);
    background: var(--bg-glass);
    backdrop-filter: blur(30px) saturate(1.8);
    -webkit-backdrop-filter: blur(30px) saturate(1.8);
    border-right: 1px solid rgba(255, 255, 255, 0.08);
    overflow-y: auto;
    overflow-x: hidden;
    padding: 12px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    z-index: 10;
}

.panel {
    background: rgba(30, 30, 46, 0.5);
    border: 1px solid rgba(255, 255, 255, 0.07);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all var(--transition-normal);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.04), 0 2px 8px rgba(0, 0, 0, 0.2);
}

.panel:hover {
    border-color: rgba(255, 255, 255, 0.12);
    box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.06), 0 4px 16px rgba(0, 0, 0, 0.3), var(--shadow-glow);
}

.panel-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 14px;
    cursor: pointer;
}

.panel-header h3 {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.panel-header h3 svg {
    color: var(--accent);
    flex-shrink: 0;
}

.collapse-btn {
    width: 24px;
    height: 24px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: none;
    background: transparent;
    color: var(--text-tertiary);
    cursor: pointer;
    border-radius: var(--radius-sm);
    transition: all var(--transition-fast);
}

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

.collapse-btn.collapsed svg {
    transform: rotate(-90deg);
}

.panel-content {
    padding: 0 14px 14px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    transition: all var(--transition-normal);
}

.panel-content.collapsed {
    display: none;
}

/* ============================================
   Form Elements
   ============================================ */
.input-group {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.input-group label {
    font-size: 0.78rem;
    font-weight: 500;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.value-display {
    color: var(--text-primary);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    font-weight: 700;
}

.code-input-wrap {
    position: relative;
}

.code-input {
    width: 100%;
    padding: 8px 12px;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.95rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    outline: none;
    transition: all var(--transition-fast);
}

.code-input:focus {
    border-color: var(--border-focus);
    box-shadow: 0 0 0 3px hsla(var(--accent-hue), 80%, 60%, 0.1);
}

.input-hint {
    position: absolute;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 0.75rem;
    color: var(--text-secondary);
    pointer-events: none;
    opacity: 0;
    transition: opacity var(--transition-fast);
}

.code-input:focus + .input-hint,
.code-input:placeholder-shown + .input-hint {
    opacity: 1;
}

.select-input {
    width: 100%;
    padding: 8px 12px;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.85rem;
    outline: none;
    cursor: pointer;
    appearance: none;
    -webkit-appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%239898b0' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 10px center;
    transition: all var(--transition-fast);
}

.select-input:focus {
    border-color: var(--border-focus);
    box-shadow: 0 0 0 3px hsla(var(--accent-hue), 80%, 60%, 0.1);
}

/* Range Slider */
.range-slider {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 6px;
    background: var(--bg-primary);
    border-radius: 3px;
    outline: none;
    cursor: pointer;
    border: 1px solid var(--border);
}

.range-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 16px;
    height: 16px;
    background: var(--accent);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 0 8px hsla(var(--accent-hue), 80%, 60%, 0.4);
    transition: all var(--transition-fast);
}

.range-slider::-webkit-slider-thumb:hover {
    transform: scale(1.2);
    box-shadow: 0 0 14px hsla(var(--accent-hue), 80%, 60%, 0.6);
}

.range-slider::-moz-range-thumb {
    width: 16px;
    height: 16px;
    background: var(--accent);
    border-radius: 50%;
    cursor: pointer;
    border: none;
    box-shadow: 0 0 8px hsla(var(--accent-hue), 80%, 60%, 0.4);
}

.hue-range {
    background: linear-gradient(to right,
        hsl(0,85%,60%), hsl(30,85%,60%), hsl(60,85%,60%),
        hsl(90,85%,60%), hsl(120,85%,60%), hsl(150,85%,60%),
        hsl(180,85%,60%), hsl(210,85%,60%), hsl(240,85%,60%),
        hsl(270,85%,60%), hsl(300,85%,60%), hsl(330,85%,60%),
        hsl(360,85%,60%));
    border: none;
}

/* Toggle */
.toggle-group {
    display: flex;
    align-items: center;
}

.toggle-label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    font-size: 0.82rem;
    color: var(--text-secondary);
    user-select: none;
}

.toggle-label input {
    display: none;
}

.toggle-switch {
    width: 36px;
    height: 20px;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: 10px;
    position: relative;
    transition: all var(--transition-fast);
    flex-shrink: 0;
}

.toggle-switch::after {
    content: '';
    position: absolute;
    top: 2px;
    left: 2px;
    width: 14px;
    height: 14px;
    background: var(--text-tertiary);
    border-radius: 50%;
    transition: all var(--transition-fast);
}

.toggle-label input:checked + .toggle-switch {
    background: var(--accent-dim);
    border-color: var(--accent);
}

.toggle-label input:checked + .toggle-switch::after {
    left: 18px;
    background: var(--text-primary);
}

/* ============================================
   Buttons
   ============================================ */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 7px 14px;
    border: 1px solid var(--border);
    background: var(--bg-elevated);
    color: var(--text-secondary);
    font-family: inherit;
    font-size: 0.82rem;
    font-weight: 500;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

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

.btn-secondary {
    width: 100%;
    justify-content: center;
    padding: 9px 14px;
}

.btn-accent {
    background: var(--accent-dim);
    border-color: var(--accent);
    color: var(--text-primary);
}

.btn-accent:hover {
    background: var(--accent);
    box-shadow: var(--shadow-glow);
}

.poly-only {
    display: none;
}

.poly-mode .poly-only {
    display: flex;
}

/* ============================================
   Canvas Area
   ============================================ */
.canvas-area {
    flex: 1;
    position: relative;
    overflow: hidden;
    background: transparent;
}

#tree-canvas {
    width: 100%;
    height: 100%;
    display: block;
}

.beat-counter {
    position: absolute;
    top: 16px;
    right: 20px;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 10px 18px;
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    z-index: 5;
}

.beat-label {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--text-secondary);
    margin-bottom: 4px;
}

.beat-number {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--accent);
    line-height: 1;
}

.waveform-canvas {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 60px;
    pointer-events: none;
    opacity: 0.5;
}

/* ============================================
   Transport Bar
   ============================================ */
.transport-bar {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: var(--transport-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 20px;
    background: var(--bg-glass);
    backdrop-filter: blur(30px) saturate(1.8);
    -webkit-backdrop-filter: blur(30px) saturate(1.8);
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    z-index: 100;
}

.transport-left, .transport-right {
    display: flex;
    align-items: center;
    gap: 12px;
    min-width: 200px;
}

.transport-right {
    justify-content: flex-end;
}

.transport-center {
    display: flex;
    align-items: center;
    gap: 4px;
}

.transport-btn {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--border);
    background: var(--bg-elevated);
    color: var(--text-secondary);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.transport-btn:hover {
    color: var(--text-primary);
    border-color: var(--border-hover);
    background: var(--bg-tertiary);
}

.transport-btn.active {
    color: var(--accent);
    border-color: var(--accent-dim);
    background: var(--accent-bg);
}

.play-btn {
    width: 52px;
    height: 52px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--accent-dim), var(--accent));
    border: none;
    color: white;
    box-shadow: 0 0 20px hsla(var(--accent-hue), 80%, 60%, 0.3);
}

.play-btn:hover {
    transform: scale(1.08);
    box-shadow: 0 0 30px hsla(var(--accent-hue), 80%, 60%, 0.5);
    background: linear-gradient(135deg, var(--accent), var(--accent-glow));
    color: white;
}

.play-btn.playing {
    animation: pulse-glow 1.5s ease-in-out infinite;
}

@keyframes pulse-glow {
    0%, 100% { box-shadow: 0 0 20px hsla(var(--accent-hue), 80%, 60%, 0.3); }
    50% { box-shadow: 0 0 35px hsla(var(--accent-hue), 80%, 60%, 0.6); }
}

.time-display {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-primary);
    display: flex;
    align-items: baseline;
    gap: 4px;
}

.time-current {
    color: var(--text-primary);
    font-weight: 600;
}

.time-separator {
    color: var(--text-tertiary);
}

.tempo-display {
    display: flex;
    align-items: center;
    gap: 6px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
}

/* ============================================
   Modals
   ============================================ */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(8px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-normal);
}

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

.modal {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    width: 90%;
    max-width: 520px;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
    transform: translateY(20px) scale(0.95);
    transition: transform var(--transition-normal);
}

.modal-overlay.active .modal {
    transform: translateY(0) scale(1);
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 20px 24px 0;
}

.modal-header h2 {
    font-size: 1.2rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent), var(--cyan));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.modal-close {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: none;
    background: var(--bg-tertiary);
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
}

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

.modal-body {
    padding: 20px 24px 24px;
}

.modal-body h3 {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
    margin-top: 16px;
}
.modal-body h3:first-child {
    margin-top: 0;
}

.modal-body p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.modal-body ul {
    list-style: none;
    padding: 0;
}
.modal-body ul li {
    font-size: 0.85rem;
    color: var(--text-secondary);
    padding: 4px 0;
    padding-left: 16px;
    position: relative;
}
.modal-body ul li::before {
    content: '›';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-weight: 700;
}

.syntax-table {
    display: flex;
    flex-direction: column;
    gap: 6px;
    margin-bottom: 8px;
}

.syntax-row {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 6px 10px;
    background: var(--bg-tertiary);
    border-radius: var(--radius-sm);
}

.syntax-row code {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--accent);
    min-width: 80px;
}

.syntax-row span {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

/* Export Options */
.export-options {
    display: flex;
    flex-direction: column;
    gap: 10px;
    margin-top: 8px;
}

.export-option {
    display: flex;
    align-items: center;
    gap: 14px;
    padding: 16px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all var(--transition-fast);
    text-align: left;
    color: var(--text-primary);
    font-family: inherit;
}

.export-option:hover {
    border-color: var(--accent-dim);
    background: var(--accent-bg);
    box-shadow: var(--shadow-glow);
}

.export-option svg {
    color: var(--accent);
    flex-shrink: 0;
}

.export-title {
    font-size: 0.92rem;
    font-weight: 600;
    display: block;
}

.export-desc {
    font-size: 0.78rem;
    color: var(--text-tertiary);
    display: block;
    margin-top: 2px;
}

/* ============================================
   Responsive
   ============================================ */
@media (max-width: 900px) {
    .sidebar {
        position: fixed;
        top: var(--header-height);
        bottom: var(--transport-height);
        left: -320px;
        z-index: 50;
        transition: left var(--transition-slow);
    }
    .sidebar.open {
        left: 0;
    }
    .header-center {
        display: none;
    }
}

/* ============================================
   Animations
   ============================================ */
@keyframes node-pop {
    0% { transform: scale(0.6); opacity: 0; }
    60% { transform: scale(1.1); }
    100% { transform: scale(1); opacity: 1; }
}

@keyframes line-draw {
    from { stroke-dashoffset: 100; }
    to { stroke-dashoffset: 0; }
}

/* Loading shimmer */
@keyframes shimmer {
    0% { background-position: -200% 0; }
    100% { background-position: 200% 0; }
}

/* Notification toast */
.toast {
    position: fixed;
    bottom: calc(var(--transport-height) + 16px);
    left: 50%;
    transform: translateX(-50%) translateY(20px);
    padding: 10px 20px;
    background: var(--bg-elevated);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    color: var(--text-primary);
    font-size: 0.85rem;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    z-index: 200;
    pointer-events: none;
    transition: all var(--transition-normal);
}

.toast.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* ============================================
   Level-Specific Controls Overlay
   ============================================ */
.level-controls-overlay {
    position: absolute;
    right: 20px;
    width: 205px;
    background: var(--bg-glass);
    backdrop-filter: blur(24px) saturate(1.6);
    -webkit-backdrop-filter: blur(24px) saturate(1.6);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 10px;
    z-index: 50;
    pointer-events: auto;
    box-shadow: var(--shadow-lg);
    transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1), 
                opacity 0.4s ease;
}

.level-controls-overlay.upper {
    top: 100px;
    border-right: 4px solid var(--accent);
}

.level-controls-overlay.lower {
    bottom: 20px;
    border-right: 4px solid var(--cyan);
}

.level-controls-title {
    font-size: 0.7rem;
    font-weight: 800;
    color: var(--text-tertiary);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 4px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.level-controls-title::after {
    content: '';
    flex: 1;
    height: 1px;
    background: var(--border);
}

.level-control-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
}

.level-label {
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.level-select {
    flex: 1;
    background: var(--bg-tertiary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    padding: 4px 6px;
    font-family: inherit;
    font-size: 0.8rem;
    cursor: pointer;
    outline: none;
    transition: all var(--transition-fast);
}

.level-select:focus, .level-select:hover {
    border-color: var(--border-focus);
    background: var(--bg-elevated);
}

.level-controls-overlay:empty {
    opacity: 0;
    transform: translateX(20px);
    pointer-events: none;
}