/* Hack Orbit Project
Copyright © Hack Orbit Global.
Open-source for learning only. Credit required. No commercial use. */

/* ---------- CSS Custom Properties ---------- */
:root {
    /* Colors */
    --bg-primary: #0a0a0f;
    --bg-secondary: #111118;
    --bg-tertiary: #1a1a24;
    --bg-card: rgba(20, 20, 35, 0.7);
    --bg-glass: rgba(20, 20, 40, 0.6);
    --bg-glass-hover: rgba(30, 30, 55, 0.75);

    --text-primary: #e8e8f0;
    --text-secondary: #9090a8;
    --text-muted: #606078;
    --text-code: #c8d0e0;

    --neon-blue: #00aaff;
    --neon-purple: #aa00ff;
    --neon-yellow: #ffdd00;
    --neon-green: #00ff88;
    --neon-red: #ff4466;
    --neon-orange: #ff8800;

    --gradient-primary: linear-gradient(135deg, #00aaff, #aa00ff);
    --gradient-alt: linear-gradient(135deg, #aa00ff, #ff4466);
    --gradient-warm: linear-gradient(135deg, #ff8800, #ffdd00);

    --border-glass: rgba(255, 255, 255, 0.08);
    --border-hover: rgba(0, 170, 255, 0.3);

    --shadow-glow-blue: 0 0 20px rgba(0, 170, 255, 0.15);
    --shadow-glow-purple: 0 0 20px rgba(170, 0, 255, 0.15);

    /* Sizing */
    --navbar-height: 64px;
    --sidebar-width: 260px;
    --code-panel-width: 320px;
    --border-radius: 16px;
    --border-radius-sm: 10px;
    --border-radius-xs: 6px;

    /* Typography */
    --font-main: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-base: 0.25s ease;
    --transition-slow: 0.4s ease;
    --transition-spring: 0.5s cubic-bezier(0.34, 1.56, 0.64, 1);
}

/* Light theme overrides */
body.light-theme {
    --bg-primary: #f0f0f5;
    --bg-secondary: #e8e8f0;
    --bg-tertiary: #d8d8e4;
    --bg-card: rgba(255, 255, 255, 0.7);
    --bg-glass: rgba(255, 255, 255, 0.6);
    --bg-glass-hover: rgba(255, 255, 255, 0.8);

    --text-primary: #1a1a2e;
    --text-secondary: #4a4a60;
    --text-muted: #8080a0;
    --text-code: #2a2a40;

    --border-glass: rgba(0, 0, 0, 0.08);
    --border-hover: rgba(0, 170, 255, 0.4);

    --shadow-glow-blue: 0 0 20px rgba(0, 170, 255, 0.1);
    --shadow-glow-purple: 0 0 20px rgba(170, 0, 255, 0.1);
}

/* High contrast overrides */
body.high-contrast {
    --bg-primary: #000000;
    --bg-secondary: #0a0a0a;
    --bg-card: rgba(0, 0, 0, 0.9);
    --bg-glass: rgba(0, 0, 0, 0.85);
    --text-primary: #ffffff;
    --text-secondary: #cccccc;
    --border-glass: rgba(255, 255, 255, 0.2);
    --neon-blue: #44ccff;
    --neon-purple: #cc44ff;
    --neon-yellow: #ffff44;
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-main);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a {
    color: var(--neon-blue);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--neon-purple);
}

button {
    font-family: var(--font-main);
    cursor: pointer;
    border: none;
    outline: none;
    background: transparent;
    color: var(--text-primary);
}

button:focus-visible, a:focus-visible, input:focus-visible {
    outline: 2px solid var(--neon-blue);
    outline-offset: 2px;
}

img, canvas {
    display: block;
    max-width: 100%;
}

::selection {
    background: rgba(0, 170, 255, 0.3);
    color: #fff;
}

.hidden {
    display: none !important;
}

/* ---------- Custom Cursor ---------- */
.custom-cursor {
    position: fixed;
    width: 20px;
    height: 20px;
    border: 2px solid var(--neon-blue);
    border-radius: 50%;
    pointer-events: none;
    z-index: 10000;
    transform: translate(-50%, -50%);
    transition: width 0.2s, height 0.2s, border-color 0.2s;
    mix-blend-mode: difference;
}

.custom-cursor.hover {
    width: 40px;
    height: 40px;
    border-color: var(--neon-purple);
}

.custom-cursor-trail {
    position: fixed;
    width: 6px;
    height: 6px;
    background: var(--neon-blue);
    border-radius: 50%;
    pointer-events: none;
    z-index: 9999;
    transform: translate(-50%, -50%);
    transition: transform 0.08s ease-out;
    opacity: 0.6;
}

@media (hover: none) {
    .custom-cursor, .custom-cursor-trail {
        display: none;
    }
}

/* ---------- Glass Panel Utility ---------- */
.glass-panel, .glass-card {
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-glass);
    border-radius: var(--border-radius);
}

/* ---------- Navbar ---------- */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--navbar-height);
    z-index: 1000;
    background: rgba(10, 10, 15, 0.8);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border-glass);
    transition: background var(--transition-base);
}

.nav-container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
    color: var(--text-primary);
    transition: transform var(--transition-base);
}

.nav-logo:hover {
    transform: scale(1.02);
    color: var(--text-primary);
}

.logo-svg {
    animation: logoSpin 20s linear infinite;
}

@keyframes logoSpin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.nav-logo:hover .logo-svg {
    animation-duration: 2s;
}

.logo-text {
    display: flex;
    align-items: baseline;
    gap: 2px;
    font-weight: 700;
    font-size: 1.1rem;
}

.logo-hack {
    color: var(--neon-blue);
}

.logo-orbit {
    color: var(--neon-purple);
}

.logo-dsa {
    font-size: 0.7rem;
    color: var(--text-muted);
    margin-left: 6px;
    text-transform: uppercase;
    letter-spacing: 2px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-link {
    padding: 8px 16px;
    border-radius: var(--border-radius-xs);
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    transition: all var(--transition-fast);
    position: relative;
}

.nav-link:hover, .nav-link.active {
    color: var(--text-primary);
    background: rgba(0, 170, 255, 0.08);
}

.nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 2px;
    left: 50%;
    transform: translateX(-50%);
    width: 20px;
    height: 2px;
    background: var(--gradient-primary);
    border-radius: 2px;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: 8px;
}

.theme-toggle, .contrast-toggle {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.theme-toggle:hover, .contrast-toggle:hover {
    color: var(--neon-blue);
    background: rgba(0, 170, 255, 0.1);
}

.theme-icon.moon {
    display: none;
}

body.light-theme .theme-icon.sun {
    display: none;
}

body.light-theme .theme-icon.moon {
    display: block;
}

/* Hamburger */
.nav-hamburger {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 36px;
    height: 36px;
    gap: 5px;
}

.nav-hamburger span {
    width: 22px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all var(--transition-fast);
}

.nav-hamburger.open span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.nav-hamburger.open span:nth-child(2) {
    opacity: 0;
}

.nav-hamburger.open span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* ---------- Buttons ---------- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 28px;
    border-radius: var(--border-radius-sm);
    font-size: 0.95rem;
    font-weight: 600;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

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

.btn-primary {
    background: var(--gradient-primary);
    color: #fff;
    box-shadow: 0 4px 20px rgba(0, 170, 255, 0.3);
}

.btn-primary:hover {
    box-shadow: 0 6px 30px rgba(0, 170, 255, 0.5);
    transform: translateY(-2px);
}

.btn-secondary {
    border: 1px solid var(--border-glass);
    color: var(--text-primary);
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
}

.btn-secondary:hover {
    border-color: var(--border-hover);
    background: var(--bg-glass-hover);
    transform: translateY(-2px);
}

/* ---------- Page System ---------- */
.page {
    display: none;
}

.page.active {
    display: block;
}

/* ---------- Hero Section ---------- */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: calc(var(--navbar-height) + 40px) 24px 60px;
    position: relative;
    overflow: hidden;
}

.hero-bg-particles {
    position: absolute;
    inset: 0;
    pointer-events: none;
}

.hero-content {
    max-width: 640px;
    z-index: 2;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 16px;
    border-radius: 999px;
    background: rgba(0, 170, 255, 0.08);
    border: 1px solid rgba(0, 170, 255, 0.2);
    font-size: 0.8rem;
    color: var(--neon-blue);
    margin-bottom: 24px;
    animation: fadeInUp 0.6s ease both;
}

.badge-dot {
    width: 6px;
    height: 6px;
    background: var(--neon-green);
    border-radius: 50%;
    animation: pulse 2s ease infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.5; transform: scale(1.5); }
}

.hero-title {
    font-size: clamp(2.4rem, 5vw, 4rem);
    font-weight: 800;
    line-height: 1.15;
    margin-bottom: 20px;
    letter-spacing: -0.02em;
}

.title-line {
    display: block;
    animation: fadeInUp 0.7s ease both;
}

.title-line:nth-child(2) { animation-delay: 0.1s; }
.title-line:nth-child(3) { animation-delay: 0.2s; }

.gradient-text {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.gradient-text-alt {
    background: var(--gradient-alt);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-description {
    font-size: 1.1rem;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 32px;
    animation: fadeInUp 0.7s ease 0.3s both;
}

.hero-actions {
    display: flex;
    gap: 12px;
    margin-bottom: 48px;
    animation: fadeInUp 0.7s ease 0.4s both;
    flex-wrap: wrap;
}

.hero-stats {
    display: flex;
    gap: 40px;
    animation: fadeInUp 0.7s ease 0.5s both;
}

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

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 800;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.hero-visual {
    position: relative;
    z-index: 2;
    margin-left: 40px;
}

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

/* ---------- Algorithm Cards Section ---------- */
.algo-cards-section {
    padding: 80px 24px;
    max-width: 1100px;
    margin: 0 auto;
}

.section-title {
    text-align: center;
    font-size: clamp(1.8rem, 3vw, 2.5rem);
    font-weight: 800;
    margin-bottom: 12px;
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: 48px;
}

.algo-cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.algo-card {
    position: relative;
    background: var(--bg-glass);
    backdrop-filter: blur(16px);
    border: 1px solid var(--border-glass);
    border-radius: var(--border-radius);
    padding: 36px 28px;
    cursor: pointer;
    transition: all var(--transition-base);
    overflow: hidden;
}

.algo-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-4px);
    box-shadow: var(--shadow-glow-blue);
}

.card-glow {
    position: absolute;
    top: -60%;
    left: -60%;
    width: 220%;
    height: 220%;
    background: radial-gradient(circle, rgba(0, 170, 255, 0.06) 0%, transparent 70%);
    opacity: 0;
    transition: opacity var(--transition-slow);
    pointer-events: none;
}

.algo-card:hover .card-glow {
    opacity: 1;
}

.card-icon {
    margin-bottom: 20px;
}

.card-title {
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.card-desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 16px;
}

.card-count {
    font-size: 0.75rem;
    color: var(--neon-blue);
    text-transform: uppercase;
    letter-spacing: 1.5px;
    font-weight: 600;
}

/* ---------- Features Section ---------- */
.features-section {
    padding: 80px 24px 100px;
    max-width: 1100px;
    margin: 0 auto;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
}

.feature-card {
    padding: 28px 24px;
    transition: all var(--transition-base);
}

.feature-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-2px);
}

.feature-icon {
    font-size: 2rem;
    margin-bottom: 12px;
}

.feature-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 8px;
}

.feature-card p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ============ VISUALIZER LAYOUT ============ */
.page-visualizer {
    padding-top: var(--navbar-height);
    min-height: 100vh;
}

.visualizer-layout {
    display: grid;
    grid-template-columns: var(--sidebar-width) 1fr var(--code-panel-width);
    min-height: calc(100vh - var(--navbar-height));
}

/* Sidebar */
.viz-sidebar {
    border-right: 1px solid var(--border-glass);
    border-radius: 0;
    padding: 16px;
    overflow-y: auto;
    position: sticky;
    top: var(--navbar-height);
    height: calc(100vh - var(--navbar-height));
    scrollbar-width: thin;
    scrollbar-color: var(--bg-tertiary) transparent;
    transition: transform var(--transition-base), width var(--transition-base);
}

.sidebar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-glass);
}

.sidebar-header h2 {
    font-size: 1rem;
    font-weight: 700;
    letter-spacing: 0.5px;
}

.sidebar-toggle {
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 6px;
    color: var(--text-muted);
    transition: all var(--transition-fast);
}

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

.sidebar-section {
    margin-bottom: 8px;
}

.section-header {
    display: flex;
    align-items: center;
    gap: 8px;
    width: 100%;
    padding: 10px 12px;
    border-radius: var(--border-radius-xs);
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-primary);
    transition: background var(--transition-fast);
}

.section-header:hover {
    background: var(--bg-tertiary);
}

.section-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    flex-shrink: 0;
}

.section-chevron {
    margin-left: auto;
    transition: transform var(--transition-fast);
    color: var(--text-muted);
}

.section-header[aria-expanded="false"] .section-chevron {
    transform: rotate(-90deg);
}

.section-items {
    overflow: hidden;
    transition: max-height var(--transition-base);
}

.section-header[aria-expanded="false"] + .section-items {
    max-height: 0 !important;
}

.algo-item {
    display: block;
    width: 100%;
    padding: 8px 12px 8px 28px;
    font-size: 0.82rem;
    color: var(--text-secondary);
    border-radius: var(--border-radius-xs);
    text-align: left;
    transition: all var(--transition-fast);
}

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

.algo-item.active {
    background: rgba(0, 170, 255, 0.1);
    color: var(--neon-blue);
    font-weight: 500;
}

/* Main Visualization Area */
.viz-main {
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    overflow-y: auto;
}

.viz-top-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 20px;
    flex-wrap: wrap;
    gap: 12px;
}

.viz-title-area {
    display: flex;
    align-items: center;
    gap: 12px;
}

#vizTitle {
    font-size: 1.1rem;
    font-weight: 700;
}

.viz-complexity {
    font-size: 0.75rem;
    color: var(--neon-purple);
    font-family: var(--font-mono);
    padding: 2px 8px;
    background: rgba(170, 0, 255, 0.1);
    border-radius: 4px;
}

.viz-mode-toggles {
    display: flex;
    gap: 6px;
}

.mode-btn {
    padding: 6px 14px;
    border-radius: var(--border-radius-xs);
    font-size: 0.8rem;
    font-weight: 500;
    border: 1px solid var(--border-glass);
    transition: all var(--transition-fast);
}

.mode-btn:hover {
    border-color: var(--border-hover);
    background: rgba(0, 170, 255, 0.08);
}

.mode-btn.active {
    background: rgba(0, 170, 255, 0.15);
    border-color: var(--neon-blue);
    color: var(--neon-blue);
}

/* Canvas Area */
.viz-canvas-wrapper {
    flex: 1;
    min-height: 300px;
    background: var(--bg-glass);
    border: 1px solid var(--border-glass);
    border-radius: var(--border-radius);
    position: relative;
    overflow: hidden;
    display: flex;
}

.viz-canvas-wrapper canvas {
    width: 100%;
    height: 100%;
    min-height: 300px;
}

.viz-canvas-wrapper.split canvas {
    width: 50%;
}

/* Quiz Panel */
.quiz-panel {
    padding: 16px 20px;
}

.quiz-panel h3 {
    font-size: 1rem;
    margin-bottom: 12px;
}

.quiz-options {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    margin-bottom: 10px;
}

.quiz-option {
    padding: 8px 16px;
    border: 1px solid var(--border-glass);
    border-radius: var(--border-radius-xs);
    font-size: 0.85rem;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.quiz-option:hover {
    border-color: var(--neon-blue);
    background: rgba(0, 170, 255, 0.08);
}

.quiz-option.correct {
    border-color: var(--neon-green);
    background: rgba(0, 255, 136, 0.15);
    color: var(--neon-green);
}

.quiz-option.wrong {
    border-color: var(--neon-red);
    background: rgba(255, 68, 102, 0.15);
    color: var(--neon-red);
}

.quiz-score {
    font-size: 0.8rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

.quiz-result {
    font-size: 0.9rem;
    margin-bottom: 8px;
    min-height: 1.4em;
}

/* ELI5 Panel */
.eli5-panel {
    padding: 16px 20px;
}

.eli5-panel h3 {
    font-size: 1rem;
    margin-bottom: 10px;
}

.eli5-panel p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* Controls */
.viz-controls {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 16px;
    flex-wrap: wrap;
    gap: 10px;
}

.controls-left, .controls-center, .controls-right {
    display: flex;
    align-items: center;
    gap: 6px;
}

.ctrl-btn {
    width: 38px;
    height: 38px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--border-radius-xs);
    border: 1px solid var(--border-glass);
    color: var(--text-secondary);
    font-size: 0.78rem;
    font-weight: 600;
    transition: all var(--transition-fast);
}

.ctrl-btn:hover {
    border-color: var(--border-hover);
    color: var(--neon-blue);
    background: rgba(0, 170, 255, 0.08);
}

.ctrl-play {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--gradient-primary);
    border: none;
    color: #fff;
    box-shadow: 0 2px 15px rgba(0, 170, 255, 0.4);
}

.ctrl-play:hover {
    transform: scale(1.1);
    box-shadow: 0 4px 25px rgba(0, 170, 255, 0.6);
}

/* Graph & Tree specific controls */
.graph-controls, .tree-controls {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
    flex-wrap: wrap;
}

.graph-controls .ctrl-btn, .tree-controls .ctrl-btn {
    width: auto;
    padding: 6px 14px;
}

.graph-label {
    display: flex;
    align-items: center;
    gap: 4px;
    font-size: 0.82rem;
    color: var(--text-secondary);
    cursor: pointer;
}

.tree-input {
    width: 80px;
    padding: 6px 10px;
    border: 1px solid var(--border-glass);
    border-radius: var(--border-radius-xs);
    background: var(--bg-tertiary);
    color: var(--text-primary);
    font-size: 0.85rem;
    font-family: var(--font-mono);
}

/* Sliders */
.speed-slider, .size-slider {
    -webkit-appearance: none;
    width: 100px;
    height: 4px;
    background: var(--bg-tertiary);
    border-radius: 2px;
    outline: none;
}

.speed-slider::-webkit-slider-thumb, .size-slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--neon-blue);
    cursor: pointer;
    box-shadow: 0 0 8px rgba(0, 170, 255, 0.4);
    transition: transform var(--transition-fast);
}

.speed-slider::-webkit-slider-thumb:hover, .size-slider::-webkit-slider-thumb:hover {
    transform: scale(1.3);
}

.speed-slider::-moz-range-thumb, .size-slider::-moz-range-thumb {
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--neon-blue);
    cursor: pointer;
    border: none;
    box-shadow: 0 0 8px rgba(0, 170, 255, 0.4);
}

.speed-label, .speed-value, .size-label, .size-value {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-family: var(--font-mono);
}

/* Explanation */
.viz-explanation {
    padding: 10px 20px;
}

.step-info {
    display: flex;
    align-items: center;
    gap: 16px;
}

.step-counter {
    font-size: 0.8rem;
    font-family: var(--font-mono);
    color: var(--neon-blue);
    white-space: nowrap;
}

.step-desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* Code Panel */
.viz-code-panel {
    border-left: 1px solid var(--border-glass);
    border-radius: 0;
    padding: 16px;
    overflow-y: auto;
    position: sticky;
    top: var(--navbar-height);
    height: calc(100vh - var(--navbar-height));
    scrollbar-width: thin;
    scrollbar-color: var(--bg-tertiary) transparent;
}

.code-panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--border-glass);
}

.code-panel-header h3 {
    font-size: 1rem;
    font-weight: 700;
}

.code-panel-toggle {
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 6px;
    color: var(--text-muted);
    transition: all var(--transition-fast);
}

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

.code-block {
    font-family: var(--font-mono);
    font-size: 0.78rem;
    line-height: 1.8;
    overflow-x: auto;
    white-space: pre;
    color: var(--text-code);
    counter-reset: line;
}

.code-block .code-line {
    display: block;
    padding: 1px 8px;
    border-radius: 3px;
    transition: background var(--transition-fast);
}

.code-block .code-line::before {
    counter-increment: line;
    content: counter(line);
    display: inline-block;
    width: 24px;
    text-align: right;
    margin-right: 16px;
    color: var(--text-muted);
    font-size: 0.7rem;
}

.code-block .code-line.highlight {
    background: rgba(0, 170, 255, 0.15);
    border-left: 2px solid var(--neon-blue);
}

/* Syntax highlighting */
.code-keyword { color: var(--neon-purple); }
.code-function { color: var(--neon-blue); }
.code-number { color: var(--neon-orange); }
.code-string { color: var(--neon-green); }
.code-comment { color: var(--text-muted); font-style: italic; }

/* ---------- Ad Placeholders ---------- */
.ad-placeholder {
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px dashed rgba(255, 255, 255, 0.05);
    border-radius: var(--border-radius-xs);
    background: rgba(255, 255, 255, 0.02);
    min-height: 60px;
}

.ad-sidebar {
    margin-top: auto;
    min-height: 250px;
}

.ad-below-viz {
    min-height: 90px;
}

.ad-label {
    font-size: 0.7rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
    opacity: 0.3;
}

/* ---------- Floating Help ---------- */
.floating-help {
    position: fixed;
    bottom: 24px;
    right: 24px;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--gradient-primary);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 900;
    box-shadow: 0 4px 20px rgba(0, 170, 255, 0.4);
    transition: all var(--transition-base);
}

.floating-help:hover {
    transform: scale(1.1) rotate(5deg);
    box-shadow: 0 6px 30px rgba(0, 170, 255, 0.6);
}

/* ---------- Modal ---------- */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(6px);
    z-index: 2000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 24px;
    animation: fadeIn 0.2s ease;
}

.modal {
    max-width: 560px;
    width: 100%;
    max-height: 80vh;
    overflow-y: auto;
    padding: 32px;
    position: relative;
    animation: modalSlideIn 0.3s ease;
}

.modal-close {
    position: absolute;
    top: 16px;
    right: 16px;
    font-size: 1.5rem;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    color: var(--text-muted);
    transition: all var(--transition-fast);
}

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

.modal h2 {
    font-size: 1.4rem;
    margin-bottom: 20px;
}

.modal h3 {
    font-size: 1rem;
    margin: 20px 0 12px;
}

.help-step {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px 0;
}

.help-num {
    width: 28px;
    height: 28px;
    min-width: 28px;
    border-radius: 50%;
    background: var(--gradient-primary);
    color: #fff;
    font-size: 0.8rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
}

.help-step p {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.shortcuts-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
}

.shortcut {
    font-size: 0.82rem;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 8px;
}

kbd {
    display: inline-block;
    padding: 2px 8px;
    border: 1px solid var(--border-glass);
    border-radius: 4px;
    background: var(--bg-tertiary);
    font-family: var(--font-mono);
    font-size: 0.75rem;
    min-width: 28px;
    text-align: center;
}

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

@keyframes modalSlideIn {
    from { opacity: 0; transform: translateY(20px) scale(0.97); }
    to { opacity: 1; transform: translateY(0) scale(1); }
}

/* Leaderboard */
.leaderboard-list {
    max-height: 400px;
    overflow-y: auto;
}

.leaderboard-entry {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 12px;
    border-radius: var(--border-radius-xs);
    margin-bottom: 4px;
    transition: background var(--transition-fast);
}

.leaderboard-entry:nth-child(1) {
    background: rgba(255, 215, 0, 0.08);
}

.leaderboard-entry:nth-child(2) {
    background: rgba(192, 192, 192, 0.06);
}

.leaderboard-entry:nth-child(3) {
    background: rgba(205, 127, 50, 0.06);
}

.leaderboard-rank {
    font-weight: 700;
    font-size: 0.9rem;
    min-width: 24px;
}

.leaderboard-name {
    flex: 1;
    margin-left: 12px;
    font-size: 0.85rem;
}

.leaderboard-score {
    font-family: var(--font-mono);
    font-size: 0.85rem;
    color: var(--neon-blue);
}

/* ---------- Footer ---------- */
.site-footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-glass);
    padding: 48px 24px 24px;
}

.footer-container {
    max-width: 1100px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 40px;
}

.footer-brand {
    max-width: 320px;
}

.footer-logo {
    font-weight: 700;
    font-size: 1.1rem;
    margin-bottom: 8px;
    display: block;
}

.footer-brand p {
    font-size: 0.85rem;
    color: var(--text-muted);
    line-height: 1.6;
}

.footer-links {
    display: flex;
    gap: 60px;
}

.footer-col h4 {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    color: var(--text-muted);
    margin-bottom: 12px;
}

.footer-col a {
    display: block;
    padding: 4px 0;
    font-size: 0.85rem;
    color: var(--text-secondary);
    transition: color var(--transition-fast);
}

.footer-col a:hover {
    color: var(--neon-blue);
}

.footer-bottom {
    max-width: 1100px;
    margin: 32px auto 0;
    padding-top: 20px;
    border-top: 1px solid var(--border-glass);
    text-align: center;
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* ---------- Contact Page ---------- */
.page-content {
    max-width: 800px;
    margin: 0 auto;
    padding: calc(var(--navbar-height) + 60px) 24px 80px;
}

.page-content h1 {
    font-size: clamp(1.8rem, 3vw, 2.5rem);
    font-weight: 800;
    margin-bottom: 12px;
}

.page-content .subtitle {
    color: var(--text-secondary);
    margin-bottom: 40px;
    font-size: 1.05rem;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-group label {
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.form-group input, .form-group textarea {
    padding: 12px 16px;
    background: var(--bg-glass);
    border: 1px solid var(--border-glass);
    border-radius: var(--border-radius-xs);
    color: var(--text-primary);
    font-family: var(--font-main);
    font-size: 0.95rem;
    transition: border-color var(--transition-fast);
}

.form-group input:focus, .form-group textarea:focus {
    border-color: var(--neon-blue);
    outline: none;
}

.form-group textarea {
    min-height: 120px;
    resize: vertical;
}

.form-success {
    padding: 16px;
    background: rgba(0, 255, 136, 0.1);
    border: 1px solid rgba(0, 255, 136, 0.2);
    border-radius: var(--border-radius-xs);
    color: var(--neon-green);
    font-size: 0.9rem;
    display: none;
}

/* Legal pages */
.legal-content h2 {
    font-size: 1.4rem;
    margin-top: 32px;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.legal-content h3 {
    font-size: 1.1rem;
    margin-top: 24px;
    margin-bottom: 8px;
}

.legal-content p {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 12px;
}

.legal-content ul {
    padding-left: 24px;
    margin-bottom: 12px;
}

.legal-content li {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.8;
}

.legal-content a {
    color: var(--neon-blue);
}

/* ---------- Responsive ---------- */
@media (max-width: 1100px) {
    .visualizer-layout {
        grid-template-columns: var(--sidebar-width) 1fr;
    }

    .viz-code-panel {
        position: fixed;
        top: var(--navbar-height);
        right: 0;
        width: var(--code-panel-width);
        height: calc(100vh - var(--navbar-height));
        transform: translateX(100%);
        transition: transform var(--transition-base);
        z-index: 500;
        background: var(--bg-secondary);
    }

    .viz-code-panel.open {
        transform: translateX(0);
    }
}

@media (max-width: 768px) {
    :root {
        --navbar-height: 56px;
    }

    .nav-links {
        position: fixed;
        top: var(--navbar-height);
        left: 0;
        right: 0;
        background: var(--bg-secondary);
        border-bottom: 1px solid var(--border-glass);
        flex-direction: column;
        padding: 16px;
        gap: 4px;
        transform: translateY(-100%);
        opacity: 0;
        transition: all var(--transition-base);
        z-index: 999;
    }

    .nav-links.open {
        transform: translateY(0);
        opacity: 1;
    }

    .nav-hamburger {
        display: flex;
    }

    .hero {
        flex-direction: column;
        text-align: center;
        padding: calc(var(--navbar-height) + 20px) 16px 40px;
    }

    .hero-visual {
        margin-left: 0;
        margin-top: 20px;
    }

    .hero-stats {
        justify-content: center;
    }

    .hero-actions {
        justify-content: center;
    }

    .visualizer-layout {
        grid-template-columns: 1fr;
    }

    .viz-sidebar {
        position: fixed;
        top: var(--navbar-height);
        left: 0;
        width: 280px;
        z-index: 600;
        transform: translateX(-100%);
        transition: transform var(--transition-base);
        background: var(--bg-secondary);
    }

    .viz-sidebar.open {
        transform: translateX(0);
    }

    .viz-controls {
        flex-direction: column;
    }

    .controls-left, .controls-center, .controls-right {
        width: 100%;
        justify-content: center;
    }

    .algo-cards-grid {
        grid-template-columns: 1fr;
    }

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

    .footer-links {
        gap: 30px;
    }

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

    .ad-sidebar {
        display: none;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-stats {
        gap: 20px;
    }

    .stat-number {
        font-size: 1.5rem;
    }

    .btn {
        padding: 12px 20px;
        font-size: 0.88rem;
    }

    .footer-container {
        flex-direction: column;
    }

    .footer-links {
        flex-direction: column;
    }
}

/* ---------- Scrollbar ---------- */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--bg-tertiary);
    border-radius: 3px;
}

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

/* ---------- Utility Animations ---------- */
@keyframes neonPulse {
    0%, 100% { box-shadow: 0 0 5px rgba(0, 170, 255, 0.2); }
    50% { box-shadow: 0 0 20px rgba(0, 170, 255, 0.5), 0 0 40px rgba(0, 170, 255, 0.2); }
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-6px); }
}

/* Logo easter egg animation */
.logo-easter-egg {
    animation: logoEasterEgg 1.5s ease;
}

@keyframes logoEasterEgg {
    0% { transform: scale(1) rotate(0deg); }
    25% { transform: scale(1.2) rotate(90deg); }
    50% { transform: scale(0.9) rotate(180deg); }
    75% { transform: scale(1.1) rotate(270deg); }
    100% { transform: scale(1) rotate(360deg); }
}