/* ===== Custom Properties ===== */
:root {
  --red: #DC2626;
  --red-light: #EF4444;
  --red-dark: #B91C1C;
  --red-glow: rgba(220, 38, 38, 0.15);
  --red-bg: rgba(220, 38, 38, 0.06);
  --navy: #1B365D;
  --navy-light: #234B82;
  --navy-dark: #0F2440;
  --navy-glow: rgba(27, 54, 93, 0.12);
  --navy-bg: rgba(27, 54, 93, 0.05);
  --bg: #FFFFFF;
  --bg-soft: #F8F9FC;
  --bg-card: #FFFFFF;
  --bg-card-hover: #FAFBFE;
  --border: #E8ECF2;
  --border-hover: #D0D7E2;
  --text: #1A1D26;
  --text-muted: #5A6275;
  --text-dim: #8B93A6;
  --radius: 16px;
  --radius-sm: 10px;
  --radius-lg: 24px;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.6s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow-sm: 0 1px 3px rgba(27, 54, 93, 0.06), 0 1px 2px rgba(27, 54, 93, 0.04);
  --shadow-md: 0 4px 16px rgba(27, 54, 93, 0.08), 0 2px 4px rgba(27, 54, 93, 0.04);
  --shadow-lg: 0 12px 40px rgba(27, 54, 93, 0.1), 0 4px 12px rgba(27, 54, 93, 0.05);
  --shadow-xl: 0 20px 60px rgba(27, 54, 93, 0.12), 0 8px 20px rgba(27, 54, 93, 0.06);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
  -webkit-font-smoothing: antialiased;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  overflow-x: hidden;
}

::selection {
  background: var(--red);
  color: white;
}

::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg-soft); }
::-webkit-scrollbar-thumb { background: var(--navy); border-radius: 3px; }

img { max-width: 100%; display: block; }
a { text-decoration: none; color: inherit; }
button { border: none; background: none; cursor: pointer; font-family: inherit; color: inherit; }

/* Skip link (accessibility & SEO) */
.skip-link {
  position: absolute;
  top: -100px;
  left: 16px;
  z-index: 9999;
  padding: 12px 20px;
  background: var(--navy);
  color: white;
  font-weight: 600;
  border-radius: var(--radius-sm);
  transition: top 0.2s ease;
}
.skip-link:focus {
  top: 16px;
  outline: 2px solid var(--red);
  outline-offset: 2px;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Scroll Progress ===== */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--red), var(--navy), var(--red-light));
  z-index: 1001;
  width: 0%;
  transition: none;
}

/* ===== Reveal Animation ===== */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s cubic-bezier(0.4, 0, 0.2, 1), transform 0.8s cubic-bezier(0.4, 0, 0.2, 1);
}
.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Navigation ===== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 16px 0;
  transition: var(--transition);
}

.navbar.scrolled {
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-bottom: 1px solid var(--border);
  padding: 10px 0;
  box-shadow: var(--shadow-sm);
}

.nav-container {
  position: relative;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo { flex-shrink: 0; }

.nav-links {
  position: absolute;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 32px;
}

.nav-right {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-shrink: 0;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.2rem;
  color: var(--navy-dark);
}

.nav-logo-img {
  width: 36px;
  height: 36px;
  border-radius: 8px;
}


.nav-links a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: var(--transition);
  position: relative;
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--red);
  transition: var(--transition);
  border-radius: 1px;
}

.nav-links a:hover { color: var(--navy); }
.nav-links a:hover::after { width: 100%; }

/* Language switcher */
.lang-switcher {
  display: flex;
  align-items: center;
  gap: 4px;
}

.lang-btn {
  padding: 6px 12px;
  border-radius: 8px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-muted);
  background: transparent;
  border: 1px solid transparent;
  transition: var(--transition);
}

.lang-btn:hover {
  color: var(--navy);
}

.lang-btn[aria-pressed="true"] {
  color: var(--navy);
  background: var(--navy-bg);
  border-color: rgba(27, 54, 93, 0.2);
}

.lang-sep {
  color: var(--border-hover);
  font-weight: 300;
  user-select: none;
}

.nav-cta {
  padding: 10px 24px;
  border-radius: 50px;
  font-size: 0.85rem;
  font-weight: 600;
  background: var(--navy);
  color: white;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.nav-cta:hover {
  background: var(--navy-dark);
  box-shadow: 0 4px 16px var(--navy-glow);
  transform: translateY(-1px);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 4px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--navy);
  border-radius: 2px;
  transition: var(--transition);
}

/* ===== Hero ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 120px 24px 80px;
  overflow: hidden;
  background: linear-gradient(180deg, #F0F4FA 0%, #FFFFFF 50%, var(--bg-soft) 100%);
}

/* Particle Heart Canvas */
.hero-canvas {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

.hero-bg {
  position: absolute;
  inset: 0;
  overflow: hidden;
}

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

.hero-orb-1 {
  width: 600px;
  height: 600px;
  background: var(--red);
  top: -250px;
  right: -200px;
  opacity: 0.07;
  animation-delay: 0s;
}

.hero-orb-2 {
  width: 500px;
  height: 500px;
  background: var(--navy);
  bottom: -200px;
  left: -150px;
  opacity: 0.06;
  animation-delay: -7s;
}

.hero-orb-3 {
  width: 350px;
  height: 350px;
  background: var(--red-light);
  top: 40%;
  left: 60%;
  opacity: 0.04;
  animation-delay: -14s;
}

.hero-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 80px 80px;
  opacity: 0.3;
  mask-image: radial-gradient(ellipse at center, black 20%, transparent 65%);
  -webkit-mask-image: radial-gradient(ellipse at center, black 20%, transparent 65%);
}

@keyframes orbFloat {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33% { transform: translate(30px, -30px) scale(1.05); }
  66% { transform: translate(-20px, 20px) scale(0.95); }
}

.hero-content {
  position: relative;
  text-align: center;
  max-width: 800px;
  z-index: 2;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 20px;
  border-radius: 50px;
  background: white;
  border: 1px solid var(--border);
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 32px;
  box-shadow: var(--shadow-sm);
}

.badge-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #22c55e;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; box-shadow: 0 0 0 0 rgba(34, 197, 94, 0.4); }
  50% { opacity: 0.8; box-shadow: 0 0 0 8px rgba(34, 197, 94, 0); }
}

.hero-title {
  font-size: clamp(2.8rem, 7vw, 5rem);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: 24px;
  color: var(--navy-dark);
}

/* Stagger text animation */
.hero-title .char {
  display: inline-block;
  opacity: 0;
  transform: translateY(40px) rotateX(-40deg);
  animation: charReveal 0.6s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.hero-title .char-space {
  display: inline-block;
  width: 0.3em;
}

@keyframes charReveal {
  to {
    opacity: 1;
    transform: translateY(0) rotateX(0);
  }
}

.hero-title-line { display: block; perspective: 600px; }

.hero-title-gradient {
  background: linear-gradient(135deg, var(--red), var(--navy), var(--red-dark));
  background-size: 200% 200%;
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  opacity: 0;
  transform: translateY(30px);
}

.hero-title-gradient.line-reveal {
  animation:
    lineReveal 0.8s cubic-bezier(0.16, 1, 0.3, 1) 0.7s forwards,
    gradientShift 4s ease-in-out 1.5s infinite;
}

@keyframes lineReveal {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes gradientShift {
  0%, 100% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
}

.hero-subtitle {
  font-size: clamp(1rem, 2.5vw, 1.2rem);
  color: var(--text-muted);
  max-width: 580px;
  margin: 0 auto 40px;
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

.store-btn {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 14px 28px;
  border-radius: 14px;
  background: var(--navy-dark);
  color: white;
  border: none;
  transition: var(--transition);
  box-shadow: var(--shadow-md);
}

.store-btn:hover {
  background: var(--navy);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.store-btn small {
  display: block;
  font-size: 0.65rem;
  color: rgba(255, 255, 255, 0.7);
  text-align: left;
  letter-spacing: 0.02em;
}

.store-btn strong {
  display: block;
  font-size: 1rem;
  font-weight: 600;
  text-align: left;
  color: white;
}

.store-btn-lg { padding: 18px 36px; }
.store-btn-lg strong { font-size: 1.15rem; }

.hero-stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 32px;
}

.hero-stat strong {
  display: block;
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--navy);
}

.hero-stat span {
  font-size: 0.8rem;
  color: var(--text-dim);
}

.hero-stat-divider {
  width: 1px;
  height: 32px;
  background: var(--border);
}

.scroll-indicator {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  animation: fadeInUp 1s ease 1.5s both;
}

.scroll-indicator span {
  font-size: 0.7rem;
  color: var(--text-dim);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.scroll-mouse {
  width: 24px;
  height: 38px;
  border: 2px solid var(--border-hover);
  border-radius: 12px;
  position: relative;
}

.scroll-wheel {
  width: 3px;
  height: 8px;
  background: var(--navy);
  border-radius: 2px;
  position: absolute;
  top: 6px;
  left: 50%;
  transform: translateX(-50%);
  animation: scrollWheel 2s ease-in-out infinite;
}

@keyframes scrollWheel {
  0% { opacity: 1; transform: translateX(-50%) translateY(0); }
  100% { opacity: 0; transform: translateX(-50%) translateY(14px); }
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateX(-50%) translateY(20px); }
  to { opacity: 1; transform: translateX(-50%) translateY(0); }
}

/* ===== Section Shared ===== */
.section-header { text-align: center; margin-bottom: 64px; }

.section-tag {
  display: inline-block;
  padding: 6px 16px;
  border-radius: 50px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--red);
  background: var(--red-bg);
  border: 1px solid rgba(220, 38, 38, 0.12);
  margin-bottom: 20px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.section-title {
  font-size: clamp(2rem, 4.5vw, 3rem);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.02em;
  margin-bottom: 16px;
  color: var(--navy-dark);
}

.section-subtitle {
  font-size: 1.05rem;
  color: var(--text-muted);
  max-width: 520px;
  margin: 0 auto;
}

/* ===== Interactive Quiz Demo ===== */
.demo-section {
  padding: 120px 0;
  position: relative;
  background: var(--bg-soft);
}

.quiz-wrapper {
  max-width: 560px;
  margin: 0 auto;
  position: relative;
  z-index: 2;
}

.quiz-progress {
  height: 4px;
  background: var(--border);
  border-radius: 2px;
  margin-bottom: 24px;
  overflow: hidden;
}

.quiz-progress-bar {
  height: 100%;
  width: 20%;
  background: linear-gradient(90deg, var(--red), var(--navy));
  border-radius: 2px;
  transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 3D Tilt Card */
.tilt-card {
  transform-style: preserve-3d;
  transition: transform 0.1s ease, box-shadow 0.3s ease;
  will-change: transform;
}

.tilt-card .tilt-shine {
  position: absolute;
  inset: 0;
  border-radius: inherit;
  pointer-events: none;
  z-index: 10;
  opacity: 0;
  transition: opacity 0.3s ease;
  background: radial-gradient(
    circle at var(--shine-x, 50%) var(--shine-y, 50%),
    rgba(255, 255, 255, 0.25) 0%,
    transparent 60%
  );
}

.tilt-card:hover .tilt-shine { opacity: 1; }

.quiz-card {
  background: white;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 40px;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}

.quiz-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--red), var(--navy));
}

.quiz-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 24px;
}

.quiz-category {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--navy);
  background: var(--navy-bg);
  padding: 4px 12px;
  border-radius: 50px;
  border: 1px solid rgba(27, 54, 93, 0.1);
}

.quiz-counter {
  font-size: 0.85rem;
  color: var(--text-dim);
  font-weight: 500;
}

.quiz-question {
  font-size: 1.25rem;
  font-weight: 600;
  line-height: 1.5;
  margin-bottom: 28px;
  color: var(--navy-dark);
}

.quiz-options {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.quiz-option {
  padding: 16px 20px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-size: 0.95rem;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  gap: 14px;
  background: white;
}

.quiz-option::before {
  content: attr(data-letter);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 30px;
  border-radius: 8px;
  background: var(--bg-soft);
  font-weight: 700;
  font-size: 0.8rem;
  color: var(--text-muted);
  flex-shrink: 0;
  transition: var(--transition);
}

.quiz-option:hover {
  border-color: var(--navy);
  background: var(--navy-bg);
  box-shadow: var(--shadow-sm);
}

.quiz-option:hover::before {
  background: var(--navy);
  color: white;
}

.quiz-option.correct {
  border-color: #16a34a;
  background: rgba(22, 163, 74, 0.06);
}

.quiz-option.correct::before {
  background: #16a34a;
  color: white;
}

.quiz-option.incorrect {
  border-color: var(--red);
  background: var(--red-bg);
}

.quiz-option.incorrect::before {
  background: var(--red);
  color: white;
}

.quiz-option.disabled {
  pointer-events: none;
  opacity: 0.5;
}

.quiz-option.correct.disabled,
.quiz-option.incorrect.disabled {
  opacity: 1;
}

.quiz-feedback {
  margin-top: 24px;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  display: none;
}

.quiz-feedback.show { display: block; animation: fadeIn 0.4s ease; }

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.quiz-feedback-icon {
  font-size: 1.5rem;
  margin-bottom: 8px;
}

.quiz-explanation {
  font-size: 0.9rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 20px;
}

.quiz-next-btn {
  padding: 12px 28px;
  border-radius: 12px;
  font-size: 0.9rem;
  font-weight: 600;
  background: var(--navy);
  color: white;
  transition: var(--transition);
  width: 100%;
}

.quiz-next-btn:hover {
  background: var(--navy-dark);
  transform: translateY(-1px);
  box-shadow: 0 4px 16px var(--navy-glow);
}

/* Quiz Results */
.quiz-results {
  text-align: center;
  padding: 60px 40px;
  background: white;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
}

.results-icon { font-size: 3.5rem; margin-bottom: 16px; }
.results-title { font-size: 1.8rem; font-weight: 800; margin-bottom: 8px; color: var(--navy-dark); }
.results-score { font-size: 1.1rem; color: var(--text-muted); margin-bottom: 8px; }
.results-message { font-size: 0.95rem; color: var(--text-dim); margin-bottom: 32px; }

.results-actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

.quiz-restart-btn {
  padding: 14px 32px;
  border-radius: 12px;
  font-size: 0.95rem;
  font-weight: 600;
  border: 1px solid var(--border);
  background: white;
  color: var(--navy);
  transition: var(--transition);
}

.quiz-restart-btn:hover {
  border-color: var(--navy);
  background: var(--navy-bg);
}

.quiz-download-btn {
  padding: 14px 32px;
  border-radius: 12px;
  font-size: 0.95rem;
  font-weight: 600;
  background: var(--red);
  color: white;
  transition: var(--transition);
}

.quiz-download-btn:hover {
  background: var(--red-dark);
  transform: translateY(-1px);
  box-shadow: 0 4px 16px var(--red-glow);
}

/* Quiz Decorative */
.quiz-decoration { position: relative; pointer-events: none; }

.quiz-float {
  position: absolute;
  font-size: 2rem;
  opacity: 0.2;
  animation: floatEmoji 6s ease-in-out infinite;
}

.quiz-float-1 { top: -80px; left: 10%; animation-delay: 0s; }
.quiz-float-2 { top: -40px; right: 8%; animation-delay: -1.5s; }
.quiz-float-3 { bottom: 20px; left: 5%; animation-delay: -3s; }
.quiz-float-4 { bottom: 60px; right: 12%; animation-delay: -4.5s; }

@keyframes floatEmoji {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-20px) rotate(10deg); }
}

/* ===== Features Bento Grid ===== */
.features-section {
  padding: 120px 0;
  position: relative;
}

.bento-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.bento-card {
  background: white;
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 36px;
  transition: var(--transition-slow);
  position: relative;
  overflow: hidden;
}

.bento-card:hover {
  border-color: var(--border-hover);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.bento-card-large { grid-column: span 2; }
.bento-card-wide { grid-column: span 2; }

.bento-icon {
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 14px;
  background: var(--red-bg);
  color: var(--red);
  margin-bottom: 20px;
}

.bento-icon svg { width: 28px; height: 28px; }

.bento-icon-voice { background: var(--navy-bg); color: var(--navy); }
.bento-icon-badge { background: rgba(220, 120, 15, 0.07); color: #D97706; }
.bento-icon-category { background: var(--navy-bg); color: var(--navy-light); }
.bento-icon-progress { background: rgba(22, 163, 74, 0.06); color: #16A34A; }
.bento-icon-theme { background: var(--red-bg); color: var(--red); }

.bento-card h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 8px;
  color: var(--navy-dark);
}

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

/* Spaced Repetition Visual */
.bento-visual { margin-top: 28px; }

.sr-timeline {
  display: flex;
  align-items: center;
  gap: 0;
  overflow: hidden;
}

.sr-dot {
  padding: 8px 14px;
  border-radius: 50px;
  font-size: 0.75rem;
  font-weight: 600;
  background: var(--red-bg);
  color: var(--red);
  white-space: nowrap;
  flex-shrink: 0;
  border: 1px solid rgba(220, 38, 38, 0.1);
  animation: srPulse 3s ease-in-out infinite;
}

.sr-dot-1 { animation-delay: 0s; }
.sr-dot-2 { animation-delay: 0.3s; }
.sr-dot-3 { animation-delay: 0.6s; }
.sr-dot-4 { animation-delay: 0.9s; }
.sr-dot-5 { animation-delay: 1.2s; }

@keyframes srPulse {
  0%, 100% { opacity: 0.6; transform: scale(0.95); }
  50% { opacity: 1; transform: scale(1); }
}

.sr-line {
  flex: 1;
  height: 2px;
  background: linear-gradient(90deg, rgba(220, 38, 38, 0.2), rgba(27, 54, 93, 0.1));
  min-width: 16px;
}

/* Progress Chart Visual */
.bento-chart {
  display: flex;
  align-items: flex-end;
  gap: 12px;
  margin-top: 28px;
  height: 80px;
}

.chart-bar {
  flex: 1;
  background: linear-gradient(to top, var(--red), var(--navy));
  border-radius: 6px 6px 0 0;
  height: var(--height);
  position: relative;
  opacity: 0.8;
  transition: var(--transition);
  animation: barGrow 1s ease-out both;
}

.chart-bar:hover { opacity: 1; }

.chart-bar span {
  position: absolute;
  bottom: -22px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.65rem;
  color: var(--text-dim);
}

@keyframes barGrow {
  from { height: 0; }
}

/* ===== Stats ===== */
.stats-section {
  padding: 80px 0;
  background: var(--navy-dark);
  color: white;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 32px;
  text-align: center;
}

.stat-number {
  font-size: clamp(2.5rem, 5vw, 3.5rem);
  font-weight: 900;
  color: white;
  line-height: 1.2;
}

.stat-label {
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.6);
  margin-top: 4px;
}

/* ===== About ===== */
.about-section {
  padding: 120px 0;
  background: var(--bg-soft);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 80px;
  align-items: center;
}

.about-content .section-title { text-align: left; }

.about-text {
  font-size: 1.05rem;
  color: var(--text-muted);
  line-height: 1.8;
  margin-bottom: 36px;
}

.about-features {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.about-feature {
  display: flex;
  gap: 16px;
  align-items: flex-start;
}

.about-feature-icon {
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
  background: var(--red-bg);
  color: var(--red);
  flex-shrink: 0;
}

.about-feature-icon svg { width: 22px; height: 22px; }

.about-feature strong {
  display: block;
  font-size: 0.95rem;
  margin-bottom: 2px;
  color: var(--navy-dark);
}

.about-feature p {
  font-size: 0.85rem;
  color: var(--text-dim);
  line-height: 1.5;
}

/* Phone Mockup */
.about-visual {
  display: flex;
  justify-content: center;
}

.phone-mockup {
  width: 280px;
  background: var(--navy-dark);
  border-radius: 40px;
  border: 3px solid rgba(27, 54, 93, 0.2);
  padding: 12px;
  position: relative;
  box-shadow: var(--shadow-xl), 0 0 80px rgba(220, 38, 38, 0.06);
  animation: phoneFloat 6s ease-in-out infinite;
}

@keyframes phoneFloat {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}

.phone-notch {
  width: 100px;
  height: 28px;
  background: var(--navy-dark);
  border-radius: 0 0 16px 16px;
  margin: 0 auto;
  position: relative;
  z-index: 2;
}

.phone-screen {
  background: #0F172A;
  border-radius: 28px;
  padding: 20px 16px;
  min-height: 440px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  color: white;
}

.mock-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: 12px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.mock-header span {
  font-size: 0.9rem;
  font-weight: 700;
}

.mock-dots {
  display: flex;
  gap: 4px;
}

.mock-dots span {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
}

.mock-card {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 16px;
  padding: 16px;
}

.mock-card-tag {
  display: inline-block;
  font-size: 0.65rem;
  font-weight: 600;
  color: var(--red-light);
  background: rgba(220, 38, 38, 0.15);
  padding: 3px 10px;
  border-radius: 50px;
  margin-bottom: 10px;
}

.mock-card-q {
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 14px;
  line-height: 1.4;
}

.mock-card-opts {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.mock-opt {
  padding: 8px 12px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: 10px;
  font-size: 0.7rem;
  color: rgba(255, 255, 255, 0.6);
}

.mock-opt-correct {
  border-color: #22c55e;
  background: rgba(34, 197, 94, 0.12);
  color: #22c55e;
}

.mock-progress {
  height: 4px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 2px;
}

.mock-progress-fill {
  height: 100%;
  width: 65%;
  background: linear-gradient(90deg, var(--red), var(--navy-light));
  border-radius: 2px;
}

.mock-streak {
  text-align: center;
  font-size: 0.75rem;
  color: rgba(255, 255, 255, 0.5);
  padding: 10px;
  background: rgba(255, 255, 255, 0.03);
  border-radius: 12px;
  border: 1px solid rgba(255, 255, 255, 0.06);
}

/* ===== CTA Section ===== */
.cta-section {
  padding: 120px 0;
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, var(--navy-dark) 0%, var(--navy) 50%, #1a3a62 100%);
  color: white;
}

.cta-content {
  text-align: center;
  position: relative;
  z-index: 1;
}

.cta-title {
  font-size: clamp(2.2rem, 5vw, 3.5rem);
  font-weight: 900;
  line-height: 1.1;
  margin-bottom: 20px;
  letter-spacing: -0.02em;
  color: white;
}

.cta-title span {
  background: linear-gradient(135deg, #ff6b6b, #ffa07a, #ff6b6b);
  background-size: 200% 200%;
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  animation: gradientShift 3s ease-in-out infinite;
}

.cta-subtitle {
  font-size: 1.1rem;
  color: rgba(255, 255, 255, 0.7);
  max-width: 480px;
  margin: 0 auto 40px;
}

.cta-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

.cta-actions .store-btn {
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  backdrop-filter: blur(10px);
}

.cta-actions .store-btn:hover {
  background: rgba(255, 255, 255, 0.2);
  border-color: rgba(255, 255, 255, 0.3);
}

.cta-bg {
  position: absolute;
  inset: 0;
  overflow: hidden;
}

.cta-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
}

.cta-orb-1 {
  width: 400px;
  height: 400px;
  background: var(--red);
  opacity: 0.12;
  top: -100px;
  left: -100px;
}

.cta-orb-2 {
  width: 400px;
  height: 400px;
  background: rgba(255, 255, 255, 0.1);
  bottom: -100px;
  right: -100px;
}

/* ===== Footer ===== */
.footer {
  padding: 80px 0 32px;
  border-top: 1px solid var(--border);
  background: var(--bg-soft);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 48px;
  margin-bottom: 48px;
}

.footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 1.15rem;
  margin-bottom: 16px;
  color: var(--navy-dark);
}

.footer-logo img { border-radius: 8px; }

.footer-brand p {
  font-size: 0.9rem;
  color: var(--text-dim);
  line-height: 1.7;
  margin-bottom: 20px;
  max-width: 320px;
}

.footer-social {
  display: flex;
  gap: 12px;
}

.footer-social a {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 10px;
  background: white;
  border: 1px solid var(--border);
  color: var(--text-muted);
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.footer-social a:hover {
  color: var(--navy);
  border-color: var(--navy);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.footer-links h4 {
  font-size: 0.85rem;
  font-weight: 700;
  margin-bottom: 16px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--navy-dark);
}

.footer-links a {
  display: block;
  font-size: 0.88rem;
  color: var(--text-dim);
  padding: 4px 0;
  transition: var(--transition);
}

.footer-links a:hover { color: var(--red); transform: translateX(4px); }

.footer-bottom {
  padding-top: 32px;
  border-top: 1px solid var(--border);
  text-align: center;
}

.footer-bottom p {
  font-size: 0.8rem;
  color: var(--text-dim);
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
  .bento-grid {
    grid-template-columns: repeat(2, 1fr);
  }
  .bento-card-large,
  .bento-card-wide {
    grid-column: span 2;
  }
  .about-grid {
    grid-template-columns: 1fr;
    gap: 48px;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(20px);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 32px;
    z-index: 999;
  }

  .nav-links.open { display: flex; }
  .nav-links a { font-size: 1.5rem; color: var(--navy-dark); }

  .nav-cta { display: none; }

  .nav-toggle { display: flex; z-index: 1000; }
  .nav-toggle.open span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
  .nav-toggle.open span:nth-child(2) { opacity: 0; }
  .nav-toggle.open span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

  .hero { padding: 100px 20px 60px; }
  .hero-title { font-size: clamp(2.2rem, 9vw, 3.5rem); }
  .hero-stats { flex-wrap: wrap; gap: 20px; }

  .bento-grid { grid-template-columns: 1fr; }
  .bento-card-large,
  .bento-card-wide { grid-column: span 1; }

  .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 24px; }

  .quiz-card { padding: 28px 20px; }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
}

@media (max-width: 480px) {
  .hero-actions {
    flex-direction: column;
    align-items: center;
  }
  .store-btn { width: 100%; max-width: 260px; justify-content: center; }
  .cta-actions {
    flex-direction: column;
    align-items: center;
  }
  .cta-actions .store-btn { width: 100%; max-width: 280px; justify-content: center; }
  .sr-timeline { flex-wrap: wrap; gap: 8px; justify-content: center; }
  .sr-line { display: none; }
}