/* ==========================================================================
   DUING.SHOP // PARTICLE — DOKYEONG KIM VIBE CODING PORTFOLIO
   Design System & Styling Sheet
   ========================================================================== */

/* --- CSS Variables & Palettes --- */
:root {
  --font-body: 'Inter', system-ui, -apple-system, sans-serif;
  --font-display: 'Syne', sans-serif;
  --font-tech: 'Orbitron', 'Space Grotesk', monospace;

  /* HSL Base Dark Theme */
  --bg-dark: #05070c;
  --bg-card: rgba(13, 18, 30, 0.65);
  --bg-card-hover: rgba(22, 30, 48, 0.85);
  --border-color: rgba(255, 255, 255, 0.1);
  --border-glow: rgba(0, 240, 255, 0.3);

  /* Primary Accent: Cyber Cyan */
  --primary-color: #00f0ff;
  --primary-rgb: 0, 240, 255;
  --primary-glow: rgba(0, 240, 255, 0.4);
  --secondary-color: #7000ff;

  --text-main: #f0f4f8;
  --text-muted: #8a99ad;
  --text-dim: #5c6878;

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 24px;
  --radius-full: 9999px;

  --transition-fast: 0.2s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-normal: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-slow: 0.8s cubic-bezier(0.16, 1, 0.3, 1);

  --backdrop-blur: blur(16px);
}

/* Color Palettes Overrides */
body.theme-cyan {
  --primary-color: #00f0ff;
  --primary-rgb: 0, 240, 255;
  --primary-glow: rgba(0, 240, 255, 0.4);
  --secondary-color: #0066ff;
}
body.theme-violet {
  --primary-color: #b042ff;
  --primary-rgb: 176, 66, 255;
  --primary-glow: rgba(176, 66, 255, 0.45);
  --secondary-color: #ff2a8d;
}
body.theme-gold {
  --primary-color: #ffb700;
  --primary-rgb: 255, 183, 0;
  --primary-glow: rgba(255, 183, 0, 0.45);
  --secondary-color: #ff4500;
}
body.theme-emerald {
  --primary-color: #00ffaa;
  --primary-rgb: 0, 255, 170;
  --primary-glow: rgba(0, 255, 170, 0.4);
  --secondary-color: #00a8ff;
}
body.theme-mono {
  --primary-color: #ffffff;
  --primary-rgb: 255, 255, 255;
  --primary-glow: rgba(255, 255, 255, 0.35);
  --secondary-color: #888888;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  background-color: var(--bg-dark);
  color: var(--text-main);
  font-family: var(--font-body);
  overflow-x: hidden;
}

body {
  position: relative;
  min-height: 100vh;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* WebGL Background Canvas */
#particle-canvas {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  z-index: 1;
  pointer-events: auto;
}

/* UI Overlay Wrapper */
#app-ui {
  position: relative;
  z-index: 10;
  pointer-events: none;
  transition: opacity var(--transition-normal);
}
#app-ui.ui-hidden {
  opacity: 0.05;
  pointer-events: none;
}
#app-ui.ui-hidden:hover {
  opacity: 1;
}

#app-ui a,
#app-ui button,
#app-ui input,
#app-ui .glass-card {
  pointer-events: auto;
}

/* Glassmorphic Container Common Utility */
.glass-card {
  background: var(--bg-card);
  backdrop-filter: var(--backdrop-blur);
  -webkit-backdrop-filter: var(--backdrop-blur);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
  transition: all var(--transition-normal);
}
.glass-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-glow);
  box-shadow: 0 12px 40px 0 var(--primary-glow);
}

/* --- Header / Navbar --- */
.navbar {
  position: fixed;
  top: 1rem;
  left: 50%;
  transform: translateX(-50%);
  width: calc(100% - 3rem);
  max-width: 1280px;
  height: 64px;
  padding: 0 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: rgba(8, 12, 22, 0.75);
  backdrop-filter: var(--backdrop-blur);
  -webkit-backdrop-filter: var(--backdrop-blur);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  z-index: 100;
  box-shadow: 0 4px 24px rgba(0, 0, 0, 0.5);
  pointer-events: auto;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.logo-text {
  font-family: var(--font-tech);
  font-weight: 700;
  font-size: 1.1rem;
  letter-spacing: 1px;
  color: #fff;
  text-decoration: none;
}

.logo-spark {
  color: var(--primary-color);
  text-shadow: 0 0 12px var(--primary-color);
  animation: sparkPulse 2s infinite ease-in-out;
}

.logo-dot {
  color: var(--primary-color);
}

.badge-vibe {
  font-family: var(--font-tech);
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 1px;
  padding: 0.2rem 0.6rem;
  border-radius: var(--radius-full);
  background: rgba(var(--primary-rgb), 0.15);
  color: var(--primary-color);
  border: 1px solid rgba(var(--primary-rgb), 0.3);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}

.nav-link {
  font-family: var(--font-tech);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 1px;
  color: var(--text-muted);
  text-decoration: none;
  transition: color var(--transition-fast);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.nav-link:hover, .nav-link.active {
  color: var(--primary-color);
}

.nav-link.highlight {
  color: #fff;
  background: rgba(255, 255, 255, 0.08);
  padding: 0.35rem 0.8rem;
  border-radius: var(--radius-full);
  border: 1px solid rgba(255, 255, 255, 0.15);
}
.nav-link.highlight:hover {
  background: rgba(var(--primary-rgb), 0.2);
  border-color: var(--primary-color);
  color: #fff;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.icon-btn {
  position: relative;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--border-color);
  background: rgba(255, 255, 255, 0.05);
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.icon-btn:hover {
  background: rgba(var(--primary-rgb), 0.2);
  border-color: var(--primary-color);
  color: #fff;
  transform: translateY(-2px);
}

.btn-tooltip {
  position: absolute;
  bottom: -32px;
  left: 50%;
  transform: translateX(-50%);
  font-family: var(--font-tech);
  font-size: 0.65rem;
  white-space: nowrap;
  background: rgba(0, 0, 0, 0.85);
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  border: 1px solid var(--border-color);
  color: #fff;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-fast);
}
.icon-btn:hover .btn-tooltip {
  opacity: 1;
}

.btn-glow-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 1.25rem;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: #000;
  font-family: var(--font-tech);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 1px;
  text-decoration: none;
  box-shadow: 0 0 20px var(--primary-glow);
  transition: all var(--transition-fast);
}
.btn-glow-primary:hover {
  transform: translateY(-2px) scale(1.03);
  box-shadow: 0 0 30px var(--primary-glow);
  color: #000;
}

/* --- Layout Containers --- */
.content-container {
  max-width: 1280px;
  margin: 0 auto;
  padding: 120px 2rem 60px 2rem;
}

.section-padding {
  padding: 80px 0;
}

.section-header {
  margin-bottom: 3rem;
  text-align: left;
}

.section-tag {
  font-family: var(--font-tech);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 2px;
  color: var(--primary-color);
  margin-bottom: 0.5rem;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 4vw, 3.2rem);
  font-weight: 800;
  line-height: 1.1;
  color: #fff;
  letter-spacing: -0.5px;
}

.section-sub {
  font-size: 1.05rem;
  color: var(--text-muted);
  margin-top: 0.5rem;
  max-width: 600px;
}

/* --- Hero Section --- */
.hero-section {
  min-height: 80vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: flex-start;
  padding: 2rem 0;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.4rem 1rem;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  font-family: var(--font-tech);
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

.pulse-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--primary-color);
  box-shadow: 0 0 10px var(--primary-color);
  animation: pulseGlow 1.5s infinite alternate;
}

.hero-title {
  font-family: var(--font-display);
  font-size: clamp(3.2rem, 7.5vw, 6.5rem);
  font-weight: 800;
  line-height: 0.95;
  letter-spacing: -2px;
  margin-bottom: 1.5rem;
}

.gradient-text {
  background: linear-gradient(135deg, #ffffff 0%, var(--primary-color) 60%, var(--secondary-color) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  filter: drop-shadow(0 0 30px var(--primary-glow));
}

.hero-subtitle-line {
  font-family: var(--font-tech);
  font-size: clamp(1.2rem, 2.5vw, 2.2rem);
  font-weight: 700;
  letter-spacing: 4px;
  color: #8a99ad;
}

.hero-description {
  font-size: clamp(1rem, 1.5vw, 1.25rem);
  color: var(--text-muted);
  max-width: 720px;
  line-height: 1.7;
  margin-bottom: 2.5rem;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
  margin-bottom: 3rem;
}

.btn-hero-primary {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.9rem 2rem;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
  color: #000;
  font-family: var(--font-tech);
  font-weight: 700;
  font-size: 0.85rem;
  letter-spacing: 1px;
  text-decoration: none;
  box-shadow: 0 0 30px var(--primary-glow);
  transition: all var(--transition-fast);
}
.btn-hero-primary:hover {
  transform: translateY(-3px) scale(1.03);
  box-shadow: 0 0 45px var(--primary-glow);
  color: #000;
}

.btn-hero-secondary {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.9rem 2rem;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid var(--border-glow);
  color: #fff;
  font-family: var(--font-tech);
  font-weight: 700;
  font-size: 0.85rem;
  letter-spacing: 1px;
  cursor: pointer;
  transition: all var(--transition-fast);
}
.btn-hero-secondary:hover {
  background: rgba(var(--primary-rgb), 0.25);
  border-color: var(--primary-color);
  transform: translateY(-3px);
  box-shadow: 0 0 25px var(--primary-glow);
}

.btn-hero-outline {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.9rem 2rem;
  border-radius: var(--radius-full);
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  font-family: var(--font-tech);
  font-weight: 600;
  font-size: 0.85rem;
  letter-spacing: 1px;
  text-decoration: none;
  transition: all var(--transition-fast);
}
.btn-hero-outline:hover {
  color: #fff;
  border-color: rgba(255, 255, 255, 0.4);
  transform: translateY(-3px);
}

/* Preset Quick Bar */
.quick-preset-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.6rem;
  padding: 0.8rem 1.2rem;
  background: rgba(8, 12, 22, 0.6);
  backdrop-filter: var(--backdrop-blur);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
}

.preset-label {
  font-family: var(--font-tech);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--text-dim);
  margin-right: 0.5rem;
}

.preset-btn {
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-muted);
  font-family: var(--font-tech);
  font-size: 0.7rem;
  font-weight: 600;
  padding: 0.4rem 0.9rem;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}
.preset-btn:hover {
  color: #fff;
  background: rgba(255, 255, 255, 0.05);
}
.preset-btn.active {
  background: rgba(var(--primary-rgb), 0.2);
  border-color: var(--primary-color);
  color: var(--primary-color);
  box-shadow: 0 0 15px rgba(var(--primary-rgb), 0.3);
}

/* --- Projects Grid --- */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.5rem;
}

.project-card {
  padding: 2rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  min-height: 280px;
  position: relative;
  overflow: hidden;
}

.project-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--primary-color), transparent);
  opacity: 0;
  transition: opacity var(--transition-fast);
}
.project-card:hover::before {
  opacity: 1;
}

.card-tag {
  font-family: var(--font-tech);
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 1.5px;
  color: var(--primary-color);
  margin-bottom: 0.75rem;
}
.card-tag.gold {
  color: #ffb700;
}

.card-title {
  font-family: var(--font-display);
  font-size: 1.4rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 0.75rem;
}

.card-desc {
  font-size: 0.92rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 1.5rem;
}

.card-tech {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 1.5rem;
}

.card-tech span {
  font-family: var(--font-tech);
  font-size: 0.65rem;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.08);
  padding: 0.2rem 0.5rem;
  border-radius: 4px;
  color: var(--text-muted);
}

.card-actions {
  display: flex;
  align-items: center;
  justify-content: flex-start;
}

.card-link {
  font-family: var(--font-tech);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 1px;
  color: #fff;
  text-decoration: none;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid var(--border-color);
  padding: 0.5rem 1.2rem;
  border-radius: var(--radius-full);
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  transition: all var(--transition-fast);
}
.card-link:hover {
  background: var(--primary-color);
  color: #000;
  border-color: var(--primary-color);
  box-shadow: 0 0 20px var(--primary-glow);
}

/* --- Tech Stack & Philosophy --- */
.stack-container {
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
}

.stack-badge-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.stack-chip {
  font-family: var(--font-tech);
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.7rem 1.4rem;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  transition: all var(--transition-fast);
}
.stack-chip:hover, .stack-chip.active {
  background: rgba(var(--primary-rgb), 0.15);
  border-color: var(--primary-color);
  color: #fff;
  transform: translateY(-3px);
  box-shadow: 0 0 20px var(--primary-glow);
}

.philosophy-quote {
  padding: 2.5rem;
  position: relative;
}

.quote-icon {
  font-size: 2.5rem;
  color: var(--primary-color);
  opacity: 0.3;
  margin-bottom: 1rem;
}

.quote-text {
  font-size: 1.15rem;
  line-height: 1.8;
  color: var(--text-main);
  font-style: italic;
  margin-bottom: 1rem;
}

.quote-author {
  font-family: var(--font-tech);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--primary-color);
  letter-spacing: 1px;
}

/* --- Footer --- */
.site-footer {
  margin-top: 100px;
  border-top: 1px solid var(--border-color);
  padding-top: 60px;
}

.footer-content {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-brand .footer-logo {
  font-family: var(--font-display);
  font-size: 1.8rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 0.5rem;
}

.footer-brand p {
  color: var(--text-muted);
  max-width: 360px;
  font-size: 0.95rem;
}

.footer-links {
  display: flex;
  gap: 4rem;
}

.link-group h4 {
  font-family: var(--font-tech);
  font-size: 0.75rem;
  letter-spacing: 1.5px;
  color: var(--primary-color);
  margin-bottom: 1rem;
}

.link-group a {
  display: block;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
  transition: color var(--transition-fast);
}
.link-group a:hover {
  color: #fff;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
  color: var(--text-dim);
  font-size: 0.8rem;
}

.back-top-btn {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  font-family: var(--font-tech);
  font-size: 0.7rem;
  font-weight: 700;
  padding: 0.4rem 1rem;
  border-radius: var(--radius-full);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 0.4rem;
  transition: all var(--transition-fast);
}
.back-top-btn:hover {
  background: var(--primary-color);
  color: #000;
  border-color: var(--primary-color);
}

/* --- HUD Control Deck --- */
.hud-container {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  width: 260px;
  padding: 1rem;
  z-index: 100;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.7);
  transition: transform var(--transition-normal), opacity var(--transition-normal);
}

.hud-container.minimized .hud-body {
  display: none;
}
.hud-container.minimized {
  width: auto;
  padding: 0.6rem 1rem;
}

.hud-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 0.75rem;
}
.hud-container.minimized .hud-header {
  margin-bottom: 0;
}

.hud-title {
  font-family: var(--font-tech);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--primary-color);
}

.hud-minimize-btn {
  background: transparent;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  font-size: 0.8rem;
}

.hud-stat-row {
  display: flex;
  justify-content: space-between;
  font-family: var(--font-tech);
  font-size: 0.65rem;
  margin-bottom: 0.4rem;
  color: var(--text-muted);
}

.hud-stat-row .stat-val {
  color: #fff;
  font-weight: 700;
}
.hud-stat-row .stat-val.highlight {
  color: var(--primary-color);
}

.hud-control-group {
  margin-top: 0.75rem;
}

.hud-control-group label {
  display: block;
  font-family: var(--font-tech);
  font-size: 0.65rem;
  color: var(--text-dim);
  margin-bottom: 0.3rem;
}

.hud-label-row {
  display: flex;
  justify-content: space-between;
  font-family: var(--font-tech);
  font-size: 0.65rem;
  color: var(--text-dim);
}

.hud-control-group input[type="range"] {
  width: 100%;
  accent-color: var(--primary-color);
  cursor: pointer;
}

.palette-picker {
  display: flex;
  gap: 0.4rem;
}

.palette-btn {
  width: 22px;
  height: 22px;
  border-radius: 50%;
  border: 2px solid transparent;
  cursor: pointer;
  transition: transform var(--transition-fast);
}
.palette-btn:hover {
  transform: scale(1.15);
}
.palette-btn.active {
  border-color: #fff;
  box-shadow: 0 0 10px rgba(255, 255, 255, 0.5);
}

.palette-btn.cyan { background: #00f0ff; }
.palette-btn.violet { background: #b042ff; }
.palette-btn.gold { background: #ffb700; }
.palette-btn.emerald { background: #00ffaa; }
.palette-btn.mono { background: #ffffff; }

.hud-actions {
  display: flex;
  gap: 0.5rem;
  margin-top: 1rem;
}

.hud-btn {
  flex: 1;
  font-family: var(--font-tech);
  font-size: 0.65rem;
  font-weight: 700;
  padding: 0.4rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  background: rgba(255, 255, 255, 0.05);
  color: #fff;
  cursor: pointer;
  transition: all var(--transition-fast);
}
.hud-btn:hover {
  background: rgba(255, 255, 255, 0.15);
}
.hud-btn.primary {
  background: rgba(var(--primary-rgb), 0.2);
  border-color: var(--primary-color);
  color: var(--primary-color);
}
.hud-btn.primary:hover {
  background: var(--primary-color);
  color: #000;
}

/* Audio Wave Visualizer */
#audio-wave-visualizer {
  position: fixed;
  top: 1.25rem;
  right: 1.5rem;
  z-index: 101;
  display: flex;
  align-items: flex-end;
  gap: 3px;
  height: 20px;
  pointer-events: none;
  opacity: 1;
  transition: opacity var(--transition-fast);
}
#audio-wave-visualizer.audio-wave-hidden {
  opacity: 0;
}
#audio-wave-visualizer span {
  width: 3px;
  background: var(--primary-color);
  border-radius: 3px;
  animation: waveBar 0.8s infinite alternate ease-in-out;
}
#audio-wave-visualizer span:nth-child(1) { height: 60%; animation-delay: 0.1s; }
#audio-wave-visualizer span:nth-child(2) { height: 100%; animation-delay: 0.3s; }
#audio-wave-visualizer span:nth-child(3) { height: 40%; animation-delay: 0.2s; }
#audio-wave-visualizer span:nth-child(4) { height: 80%; animation-delay: 0.4s; }
#audio-wave-visualizer span:nth-child(5) { height: 50%; animation-delay: 0.15s; }

/* Keyframe Animations */
@keyframes sparkPulse {
  0%, 100% { opacity: 0.4; transform: scale(0.9); }
  50% { opacity: 1; transform: scale(1.2); }
}

@keyframes pulseGlow {
  0% { opacity: 0.4; transform: scale(0.8); }
  100% { opacity: 1; transform: scale(1.2); }
}

@keyframes waveBar {
  0% { height: 20%; }
  100% { height: 100%; }
}

/* Responsive Breakpoints */
@media (max-width: 768px) {
  .navbar {
    width: calc(100% - 1.5rem);
    height: 56px;
    padding: 0 1rem;
  }
  .nav-links {
    display: none;
  }
  .badge-vibe {
    display: none;
  }
  .content-container {
    padding-top: 90px;
  }
  .hero-cta-group {
    flex-direction: column;
    align-items: stretch;
  }
  .btn-hero-primary, .btn-hero-secondary, .btn-hero-outline {
    justify-content: center;
  }
  .hud-container {
    bottom: 1rem;
    right: 1rem;
    width: calc(100vw - 2rem);
  }
  .footer-links {
    gap: 2rem;
  }
}