/* ============================================================
   PassGREGMAT — styles.css
   Design system + full page styles
   ============================================================ */

/* ---------- Google Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Fraunces:ital,opsz,wght@0,9..144,300;0,9..144,400;0,9..144,600;0,9..144,700;1,9..144,400;1,9..144,600;1,9..144,700&family=Inter:wght@300;400;500;600;700&display=swap');

/* ---------- CSS Custom Properties ---------- */
:root {
  --primary: #5f51fb;
  --primary-dark: #4338ca;
  --secondary: #8b5cf6;
  --accent: #06b6d4;
  --success: #10b981;
  --danger: #ef4444;
  --dark: #0f172a;
  --gray-900: #1e293b;
  --gray-700: #334155;
  --gray-500: #64748b;
  --gray-300: #cbd5e1;
  --gray-100: #f1f5f9;
  --white: #ffffff;
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, .08);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, .10);
  --shadow-lg: 0 12px 40px rgba(0, 0, 0, .15);
  --shadow-xl: 0 24px 60px rgba(0, 0, 0, .18);
  --font-heading: 'Fraunces', serif;
  --font-body: 'Inter', sans-serif;
  --transition: 0.3s ease;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-body);
  color: var(--gray-900);
  background: var(--white);
  line-height: 1.6;
  overflow-x: hidden;
}

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

a {
  color: inherit;
  text-decoration: none;
}

ul, ol {
  list-style: none;
}

button {
  cursor: pointer;
  border: none;
  background: none;
  font-family: var(--font-body);
}

input, textarea {
  font-family: var(--font-body);
}

/* ---------- Utilities ---------- */
.container {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 24px;
}

.text-gradient {
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
}

/* ---------- Reveal Animation ---------- */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

.reveal-delay-1 { transition-delay: 0.1s; }
.reveal-delay-2 { transition-delay: 0.2s; }
.reveal-delay-3 { transition-delay: 0.3s; }
.reveal-delay-4 { transition-delay: 0.4s; }
.reveal-delay-5 { transition-delay: 0.5s; }

/* ============================================================
   NAVIGATION
   ============================================================ */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  padding: 16px 0;
  transition: background var(--transition), backdrop-filter var(--transition), box-shadow var(--transition);
}

.nav.scrolled {
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: var(--shadow-sm);
}

.nav__inner {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav__logo {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--dark);
  display: flex;
  align-items: center;
  gap: 8px;
  white-space: nowrap;
}

.nav__logo-icon {
  font-size: 1.4rem;
}

.nav__badges {
  display: flex;
  gap: 6px;
}

.nav__badge {
  font-size: 0.7rem;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 20px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.nav__badge--gre {
  background: rgba(95, 81, 251, 0.12);
  color: var(--primary);
}

.nav__badge--gmat {
  background: rgba(6, 182, 212, 0.12);
  color: var(--accent);
}

.nav__links {
  display: flex;
  align-items: center;
  gap: 28px;
  margin-left: auto;
}

.nav__link {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--gray-700);
  transition: color var(--transition);
}

.nav__link:hover {
  color: var(--primary);
}

.nav__cta {
  background: var(--primary);
  color: var(--white) !important;
  padding: 10px 22px;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 600;
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
  white-space: nowrap;
}

.nav__cta:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(95, 81, 251, 0.4);
}

.nav__hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 4px;
  margin-left: auto;
  background: none;
  border: none;
  cursor: pointer;
}

.nav__hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--dark);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

.nav__hamburger.is-open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav__hamburger.is-open span:nth-child(2) {
  opacity: 0;
}

.nav__hamburger.is-open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.nav__mobile {
  display: none;
  position: fixed;
  top: 66px;
  left: 0;
  right: 0;
  background: rgba(255, 255, 255, 0.97);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  padding: 20px 24px 28px;
  box-shadow: var(--shadow-md);
  flex-direction: column;
  gap: 4px;
  z-index: 999;
  border-top: 1px solid var(--gray-100);
}

.nav__mobile.is-open {
  display: flex;
}

.nav__mobile .nav__link {
  padding: 12px 0;
  font-size: 1rem;
  border-bottom: 1px solid var(--gray-100);
  color: var(--gray-900);
}

.nav__mobile .nav__cta {
  margin-top: 12px;
  text-align: center;
  padding: 14px;
  border-radius: var(--radius-md);
  font-size: 1rem;
}

/* ============================================================
   HERO
   ============================================================ */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 120px 0 80px;
  overflow: hidden;
  background: linear-gradient(135deg, #0f0c2e 0%, #1a1060 30%, #1e1270 50%, #0e1a4a 75%, #062133 100%);
}

.hero__blob {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  opacity: 0.35;
  pointer-events: none;
}

.hero__blob--1 {
  width: 600px;
  height: 600px;
  background: var(--primary);
  top: -200px;
  left: -150px;
}

.hero__blob--2 {
  width: 400px;
  height: 400px;
  background: var(--secondary);
  bottom: -100px;
  left: 200px;
  opacity: 0.25;
}

.hero__blob--3 {
  width: 350px;
  height: 350px;
  background: var(--accent);
  top: 100px;
  right: -100px;
  opacity: 0.2;
}

.hero__inner {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero__content {
  color: var(--white);
}

.hero__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  padding: 8px 16px;
  border-radius: 40px;
  font-size: 0.85rem;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.9);
  margin-bottom: 28px;
  backdrop-filter: blur(10px);
}

.hero__h1 {
  font-family: var(--font-heading);
  font-size: clamp(2.8rem, 5vw, 4.2rem);
  font-weight: 700;
  line-height: 1.1;
  margin-bottom: 24px;
  color: var(--white);
}

.hero__h1 em {
  font-style: italic;
  color: rgba(255, 255, 255, 0.85);
}

.hero__h1 .text-gradient {
  background: linear-gradient(135deg, #a78bfa 0%, #06b6d4 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero__subtitle {
  font-size: 1.1rem;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.75);
  margin-bottom: 40px;
  max-width: 480px;
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 40px;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 14px 28px;
  border-radius: var(--radius-md);
  font-size: 1rem;
  font-weight: 600;
  transition: all var(--transition);
  white-space: nowrap;
}

.btn--primary {
  background: var(--white);
  color: var(--primary);
  box-shadow: 0 4px 20px rgba(255, 255, 255, 0.2);
}

.btn--primary:hover {
  background: var(--gray-100);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(255, 255, 255, 0.3);
}

.btn--ghost {
  background: rgba(255, 255, 255, 0.1);
  color: var(--white);
  border: 1px solid rgba(255, 255, 255, 0.25);
  backdrop-filter: blur(10px);
}

.btn--ghost:hover {
  background: rgba(255, 255, 255, 0.18);
  transform: translateY(-2px);
}

.btn--large {
  padding: 16px 36px;
  font-size: 1.05rem;
}

.hero__social-proof {
  display: flex;
  align-items: center;
  gap: 14px;
}

.hero__avatars {
  display: flex;
}

.hero__avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  border: 2px solid rgba(255, 255, 255, 0.6);
  margin-left: -10px;
  overflow: hidden;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  font-weight: 700;
  color: white;
}

.hero__avatar:first-child {
  margin-left: 0;
}

.hero__proof-text {
  font-size: 0.875rem;
  color: rgba(255, 255, 255, 0.8);
  font-weight: 500;
}

.hero__proof-text strong {
  color: var(--white);
}

/* ---- Phone Mockup ---- */
.hero__visual {
  display: flex;
  justify-content: center;
  align-items: center;
  position: relative;
}

.phone-mockup {
  position: relative;
  width: 280px;
  height: 560px;
  background: linear-gradient(145deg, #1e1e2e, #2d2d42);
  border-radius: 44px;
  box-shadow: 0 0 0 2px #3a3a55, 0 0 0 4px #1a1a2e, var(--shadow-xl);
  padding: 16px 12px;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.phone-mockup::before {
  content: '';
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 120px;
  height: 28px;
  background: #1a1a2e;
  border-radius: 0 0 20px 20px;
  z-index: 10;
}

.phone-status {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 4px 8px 8px;
  margin-top: 12px;
}

.phone-status__time {
  font-size: 0.7rem;
  font-weight: 600;
  color: rgba(255, 255, 255, 0.8);
}

.phone-status__icons {
  font-size: 0.6rem;
  color: rgba(255, 255, 255, 0.8);
  letter-spacing: 2px;
}

.phone-content {
  flex: 1;
  background: var(--gray-100);
  border-radius: 28px;
  overflow: hidden;
  position: relative;
  display: flex;
  flex-direction: column;
}

.phone-app-bar {
  background: var(--white);
  padding: 10px 14px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: 0 1px 4px rgba(0,0,0,0.06);
}

.phone-app-bar__logo {
  font-family: var(--font-heading);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--primary);
}

.phone-app-bar__count {
  font-size: 0.65rem;
  background: var(--primary);
  color: white;
  padding: 2px 7px;
  border-radius: 10px;
  font-weight: 600;
}

/* Hero flashcard inside phone */
.hero-card {
  margin: 12px;
  flex: 1;
  perspective: 1000px;
  cursor: pointer;
}

.hero-card__inner {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform 0.7s cubic-bezier(.4, 0, .2, 1);
}

.hero-card__inner.is-flipped {
  transform: rotateY(180deg);
}

.hero-card__front,
.hero-card__back {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border-radius: 16px;
  overflow: hidden;
}

.hero-card__front {
  background: var(--white);
  box-shadow: var(--shadow-md);
}

.hero-card__front img {
  width: 100%;
  height: 65%;
  object-fit: cover;
}

.hero-card__word-area {
  padding: 10px 12px;
}

.hero-card__word {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--dark);
}

.hero-card__tag {
  font-size: 0.6rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--primary);
  background: rgba(95, 81, 251, 0.1);
  padding: 2px 7px;
  border-radius: 10px;
  display: inline-block;
  margin-top: 4px;
}

.hero-card__hint {
  position: absolute;
  bottom: 8px;
  left: 0;
  right: 0;
  text-align: center;
  font-size: 0.6rem;
  color: var(--gray-500);
  font-weight: 500;
}

.hero-card__back {
  transform: rotateY(180deg);
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 16px;
  color: white;
}

.hero-card__back-word {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.hero-card__def-label {
  font-size: 0.6rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  opacity: 0.7;
  margin-bottom: 4px;
}

.hero-card__def {
  font-size: 0.75rem;
  line-height: 1.5;
  opacity: 0.95;
  margin-bottom: 10px;
}

.hero-card__example {
  font-size: 0.68rem;
  font-style: italic;
  opacity: 0.8;
  line-height: 1.5;
  border-top: 1px solid rgba(255,255,255,0.2);
  padding-top: 8px;
}

/* Floating Badges */
.float-badge {
  position: absolute;
  background: var(--white);
  border-radius: var(--radius-md);
  padding: 8px 14px;
  box-shadow: var(--shadow-lg);
  font-size: 0.8rem;
  font-weight: 600;
  white-space: nowrap;
  z-index: 10;
  animation: floatIn 0.6s ease forwards, gentleFloat 3s ease-in-out infinite;
  opacity: 0;
}

.float-badge--1 {
  top: 60px;
  right: -30px;
  color: var(--success);
  animation-delay: 0.8s, 0.8s;
}

.float-badge--2 {
  bottom: 140px;
  right: -40px;
  color: var(--primary);
  animation-delay: 1.2s, 1.2s;
}

.float-badge--3 {
  bottom: 80px;
  left: -30px;
  color: var(--gray-700);
  font-size: 0.72rem;
  animation-delay: 1.6s, 1.6s;
}

@keyframes floatIn {
  from { opacity: 0; transform: translateY(10px) scale(0.9); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}

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

@keyframes cardPulse {
  0%, 100% { box-shadow: 0 0 0 0 rgba(95, 81, 251, 0.3); }
  50% { box-shadow: 0 0 0 8px rgba(95, 81, 251, 0); }
}

/* ============================================================
   PROOF BAR
   ============================================================ */
.proof-bar {
  background: var(--gray-100);
  border-top: 1px solid var(--gray-300);
  border-bottom: 1px solid var(--gray-300);
  padding: 18px 0;
}

.proof-bar__inner {
  display: flex;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.proof-bar__label {
  font-size: 0.85rem;
  font-weight: 500;
  color: var(--gray-500);
  white-space: nowrap;
}

.proof-bar__pills {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.proof-pill {
  background: var(--white);
  border: 1px solid var(--gray-300);
  color: var(--gray-700);
  padding: 5px 14px;
  border-radius: 20px;
  font-size: 0.8rem;
  font-weight: 500;
  transition: all var(--transition);
}

.proof-pill:hover {
  border-color: var(--primary);
  color: var(--primary);
}

/* ============================================================
   SECTION COMMONS
   ============================================================ */
.section {
  padding: 96px 0;
}

.section--alt {
  background: var(--gray-100);
}

.section__eyebrow {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--primary);
  margin-bottom: 12px;
}

.section__title {
  font-family: var(--font-heading);
  font-size: clamp(2rem, 3.5vw, 2.8rem);
  font-weight: 700;
  line-height: 1.2;
  color: var(--dark);
  margin-bottom: 16px;
}

.section__subtitle {
  font-size: 1.05rem;
  color: var(--gray-500);
  line-height: 1.7;
  max-width: 560px;
}

.section__header {
  text-align: center;
  margin-bottom: 64px;
}

.section__header .section__subtitle {
  margin: 0 auto;
}

/* ============================================================
   PROBLEM / SOLUTION
   ============================================================ */
.vs-section__grid {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 40px;
  align-items: stretch;
}

.vs-divider {
  display: flex;
  align-items: center;
  justify-content: center;
}

.vs-divider__circle {
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: var(--gray-100);
  border: 2px solid var(--gray-300);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  font-weight: 800;
  color: var(--gray-500);
  letter-spacing: 0.05em;
}

.vs-card {
  border-radius: var(--radius-lg);
  padding: 36px;
}

.vs-card--bad {
  background: var(--gray-100);
  border: 1px solid var(--gray-300);
}

.vs-card--good {
  background: linear-gradient(135deg, rgba(95, 81, 251, 0.05), rgba(6, 182, 212, 0.05));
  border: 1px solid rgba(95, 81, 251, 0.2);
}

.vs-card__icon {
  font-size: 2.5rem;
  margin-bottom: 12px;
}

.vs-card__title {
  font-family: var(--font-heading);
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 24px;
  color: var(--dark);
}

.vs-card--bad .vs-card__title {
  color: var(--gray-500);
}

.vs-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.vs-list__item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  font-size: 0.95rem;
  line-height: 1.5;
}

.vs-list__item-icon {
  font-size: 1rem;
  flex-shrink: 0;
  margin-top: 1px;
}

.vs-card--bad .vs-list__item {
  color: var(--gray-500);
}

.vs-card--good .vs-list__item {
  color: var(--gray-700);
  font-weight: 500;
}

/* ============================================================
   HOW IT WORKS
   ============================================================ */
.how-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 40px;
  position: relative;
}

.how-grid::before {
  content: '';
  position: absolute;
  top: 40px;
  left: calc(16.67% + 40px);
  right: calc(16.67% + 40px);
  height: 2px;
  background: linear-gradient(to right, var(--primary), var(--accent));
  opacity: 0.3;
  pointer-events: none;
}

.how-step {
  text-align: center;
  padding: 32px 24px;
  background: var(--white);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--gray-100);
  transition: box-shadow var(--transition), transform var(--transition);
}

.how-step:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

.how-step__number {
  width: 72px;
  height: 72px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--white);
  margin: 0 auto 20px;
  box-shadow: 0 4px 16px rgba(95, 81, 251, 0.4);
}

.how-step__icon {
  font-size: 1.4rem;
}

.how-step__title {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 12px;
}

.how-step__desc {
  font-size: 0.925rem;
  color: var(--gray-500);
  line-height: 1.7;
}

/* ============================================================
   DEMO SECTION
   ============================================================ */
.demo-section {
  background: linear-gradient(180deg, var(--gray-100) 0%, var(--white) 100%);
}

.demo-wrapper {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 28px;
}

/* 3D Flashcard */
.demo__card {
  width: 100%;
  max-width: 400px;
  height: 480px;
  perspective: 1400px;
  cursor: pointer;
}

.demo__card-inner {
  position: relative;
  width: 100%;
  height: 100%;
  transform-style: preserve-3d;
  transition: transform 0.6s cubic-bezier(.4, 0, .2, 1);
}

.demo__card-inner.is-flipped {
  transform: rotateY(180deg);
}

.demo__card-front,
.demo__card-back {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-xl);
}

.demo__card-front {
  background: var(--white);
}

.demo__card-front img {
  width: 100%;
  height: 62%;
  object-fit: cover;
}

.demo__card-front-body {
  padding: 20px 24px;
  position: relative;
}

.demo__tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--primary);
  background: rgba(95, 81, 251, 0.1);
  padding: 3px 10px;
  border-radius: 20px;
  margin-bottom: 8px;
}

.demo__word {
  font-family: var(--font-heading);
  font-size: 2rem;
  font-weight: 700;
  color: var(--dark);
  line-height: 1.1;
}

.demo__tap-hint {
  position: absolute;
  bottom: -32px;
  left: 0;
  right: 0;
  text-align: center;
  font-size: 0.8rem;
  color: var(--gray-500);
  font-weight: 500;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

.demo__tap-hint svg {
  width: 14px;
  height: 14px;
  opacity: 0.6;
}

.demo__card-back {
  transform: rotateY(180deg);
  background: var(--white);
  display: flex;
  flex-direction: column;
  padding: 32px 28px;
}

.demo__back-word {
  font-family: var(--font-heading);
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 20px;
}

.demo__def-label {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--primary);
  margin-bottom: 8px;
}

.demo__definition {
  font-size: 1rem;
  color: var(--gray-700);
  line-height: 1.65;
  margin-bottom: 20px;
}

.demo__rule {
  border: none;
  border-top: 1px solid var(--gray-300);
  margin-bottom: 20px;
}

.demo__example-label {
  font-size: 0.72rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--gray-500);
  margin-bottom: 8px;
}

.demo__example {
  font-size: 0.925rem;
  font-style: italic;
  color: var(--gray-600, #475569);
  line-height: 1.7;
}

/* Demo Controls */
.demo__controls {
  display: flex;
  gap: 16px;
  align-items: center;
}

.demo__btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 13px 28px;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 600;
  border: 2px solid transparent;
  transition: all var(--transition);
}

.demo__btn--skip {
  background: rgba(239, 68, 68, 0.08);
  color: var(--danger);
  border-color: rgba(239, 68, 68, 0.2);
}

.demo__btn--skip:hover {
  background: var(--danger);
  color: var(--white);
  transform: translateY(-1px);
}

.demo__btn--flip {
  background: var(--gray-100);
  color: var(--gray-700);
  border-color: var(--gray-300);
}

.demo__btn--flip:hover {
  background: var(--gray-300);
  transform: translateY(-1px);
}

.demo__btn--know {
  background: rgba(16, 185, 129, 0.08);
  color: var(--success);
  border-color: rgba(16, 185, 129, 0.2);
}

.demo__btn--know:hover {
  background: var(--success);
  color: var(--white);
  transform: translateY(-1px);
}

/* Progress */
.demo__progress-wrap {
  width: 100%;
  max-width: 400px;
}

.demo__progress-labels {
  display: flex;
  justify-content: space-between;
  font-size: 0.8rem;
  color: var(--gray-500);
  margin-bottom: 8px;
  font-weight: 500;
}

.demo__progress-bar {
  height: 6px;
  background: var(--gray-300);
  border-radius: 10px;
  overflow: hidden;
}

.demo__progress-fill {
  height: 100%;
  background: linear-gradient(to right, var(--primary), var(--accent));
  border-radius: 10px;
  transition: width 0.4s ease;
  width: 0%;
}

.demo__counts {
  display: flex;
  justify-content: center;
  gap: 24px;
  font-size: 0.85rem;
  margin-top: 10px;
}

.demo__count--known {
  color: var(--success);
  font-weight: 600;
}

.demo__count--review {
  color: var(--danger);
  font-weight: 600;
}

/* Completion screen */
.demo__complete {
  display: none;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 48px 32px;
  background: var(--white);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  max-width: 400px;
  width: 100%;
}

.demo__complete.is-visible {
  display: flex;
}

.demo__complete-icon {
  font-size: 3.5rem;
  margin-bottom: 16px;
}

.demo__complete-title {
  font-family: var(--font-heading);
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 12px;
}

.demo__complete-stats {
  display: flex;
  gap: 32px;
  margin: 20px 0 28px;
}

.demo__stat {
  text-align: center;
}

.demo__stat-num {
  font-size: 2rem;
  font-weight: 700;
  font-family: var(--font-heading);
}

.demo__stat-num--known { color: var(--success); }
.demo__stat-num--review { color: var(--danger); }

.demo__stat-label {
  font-size: 0.75rem;
  color: var(--gray-500);
  margin-top: 2px;
}

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

.btn--outline {
  background: transparent;
  border: 2px solid var(--primary);
  color: var(--primary);
  padding: 12px 24px;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 600;
  transition: all var(--transition);
}

.btn--outline:hover {
  background: var(--primary);
  color: var(--white);
}

.btn--solid {
  background: var(--primary);
  color: var(--white);
  padding: 12px 24px;
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 600;
  transition: all var(--transition);
}

.btn--solid:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
}

/* ============================================================
   FEATURES GRID
   ============================================================ */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--white);
  border: 1px solid var(--gray-100);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition);
}

.feature-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-3px);
  border-color: rgba(95, 81, 251, 0.2);
}

.feature-card__icon {
  font-size: 2rem;
  margin-bottom: 16px;
  display: block;
}

.feature-card__title {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 8px;
}

.feature-card__desc {
  font-size: 0.9rem;
  color: var(--gray-500);
  line-height: 1.65;
}

/* ============================================================
   SCIENCE SECTION
   ============================================================ */
.science-section {
  background: var(--dark);
  color: var(--white);
  padding: 96px 0;
}

.science-section .section__eyebrow {
  color: var(--accent);
}

.science-section .section__title {
  color: var(--white);
}

.science-section .section__subtitle {
  color: rgba(255, 255, 255, 0.65);
  max-width: 520px;
}

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

.science__stats {
  display: flex;
  flex-direction: column;
  gap: 32px;
  margin-top: 40px;
}

.science-stat {
  display: flex;
  align-items: flex-start;
  gap: 20px;
  padding: 24px;
  background: rgba(255, 255, 255, 0.05);
  border-radius: var(--radius-md);
  border: 1px solid rgba(255, 255, 255, 0.08);
}

.science-stat__number {
  font-family: var(--font-heading);
  font-size: 2.4rem;
  font-weight: 700;
  line-height: 1;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  flex-shrink: 0;
}

.science-stat__text {
  font-size: 0.9rem;
  color: rgba(255, 255, 255, 0.7);
  line-height: 1.6;
  margin-top: 4px;
}

.science-cards {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.science-card {
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: 16px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.1);
  padding: 12px;
}

.science-card img {
  width: 90px;
  height: 90px;
  object-fit: cover;
  border-radius: var(--radius-sm);
  flex-shrink: 0;
}

.science-card__info {
  flex: 1;
}

.science-card__word {
  font-family: var(--font-heading);
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 4px;
}

.science-card__def {
  font-size: 0.78rem;
  color: rgba(255, 255, 255, 0.6);
  line-height: 1.5;
}

/* ============================================================
   TESTIMONIALS
   ============================================================ */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.testimonial-card {
  background: var(--white);
  border: 1px solid var(--gray-100);
  border-radius: var(--radius-lg);
  padding: 32px;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  gap: 16px;
  transition: box-shadow var(--transition), transform var(--transition);
}

.testimonial-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-3px);
}

.testimonial-card__stars {
  display: flex;
  gap: 3px;
  color: #f59e0b;
  font-size: 1rem;
}

.testimonial-card__text {
  font-size: 0.95rem;
  color: var(--gray-700);
  line-height: 1.7;
  flex: 1;
}

.testimonial-card__author {
  display: flex;
  align-items: center;
  gap: 12px;
  padding-top: 16px;
  border-top: 1px solid var(--gray-100);
}

.testimonial-card__avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary), var(--secondary));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.85rem;
  font-weight: 700;
  color: white;
  flex-shrink: 0;
}

.testimonial-card__name {
  font-weight: 600;
  font-size: 0.9rem;
  color: var(--dark);
}

.testimonial-card__school {
  font-size: 0.78rem;
  color: var(--primary);
  font-weight: 500;
}

/* ============================================================
   DOWNLOAD / CTA
   ============================================================ */
.download-section {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 40%, #312e81 100%);
  padding: 100px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.download-section::before {
  content: '';
  position: absolute;
  width: 500px;
  height: 500px;
  border-radius: 50%;
  background: rgba(255,255,255,0.05);
  top: -200px;
  right: -100px;
  pointer-events: none;
}

.download-section__title {
  font-family: var(--font-heading);
  font-size: clamp(2rem, 3.5vw, 2.8rem);
  font-weight: 700;
  color: var(--white);
  margin-bottom: 16px;
  line-height: 1.2;
}

.download-section__subtitle {
  font-size: 1.05rem;
  color: rgba(255, 255, 255, 0.75);
  margin-bottom: 48px;
}

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

.btn--appstore {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  background: var(--dark);
  color: var(--white);
  padding: 14px 28px;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  transition: all var(--transition);
  border: 1px solid rgba(255,255,255,0.1);
}

.btn--appstore:hover {
  background: #1e293b;
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.3);
}

.btn--appstore__icon {
  width: 24px;
  height: 24px;
  flex-shrink: 0;
}

.btn--appstore__text-top {
  font-size: 0.65rem;
  opacity: 0.75;
  display: block;
  line-height: 1;
  margin-bottom: 2px;
}

.btn--appstore__text-main {
  font-size: 1rem;
  font-weight: 700;
  display: block;
  line-height: 1;
}

.download-section__divider {
  display: flex;
  align-items: center;
  gap: 16px;
  max-width: 400px;
  margin: 0 auto 32px;
  color: rgba(255,255,255,0.4);
  font-size: 0.85rem;
}

.download-section__divider::before,
.download-section__divider::after {
  content: '';
  flex: 1;
  height: 1px;
  background: rgba(255,255,255,0.2);
}

.download-section__waitlist {
  max-width: 440px;
  margin: 0 auto;
}

.waitlist-label {
  font-size: 0.9rem;
  color: rgba(255,255,255,0.8);
  margin-bottom: 16px;
  font-weight: 500;
}

.waitlist-form {
  display: flex;
  gap: 10px;
}

.waitlist-form input {
  flex: 1;
  padding: 13px 18px;
  border-radius: var(--radius-md);
  border: 1px solid rgba(255,255,255,0.2);
  background: rgba(255,255,255,0.1);
  color: var(--white);
  font-size: 0.9rem;
  backdrop-filter: blur(10px);
  outline: none;
  transition: border-color var(--transition), background var(--transition);
}

.waitlist-form input::placeholder {
  color: rgba(255,255,255,0.5);
}

.waitlist-form input:focus {
  border-color: rgba(255,255,255,0.5);
  background: rgba(255,255,255,0.15);
}

.waitlist-form button {
  padding: 13px 22px;
  background: var(--white);
  color: var(--primary);
  border-radius: var(--radius-md);
  font-size: 0.9rem;
  font-weight: 700;
  transition: all var(--transition);
  white-space: nowrap;
}

.waitlist-form button:hover {
  background: var(--gray-100);
  transform: translateY(-1px);
}

.waitlist-success {
  display: none;
  align-items: center;
  gap: 10px;
  background: rgba(16, 185, 129, 0.15);
  border: 1px solid rgba(16, 185, 129, 0.4);
  padding: 14px 20px;
  border-radius: var(--radius-md);
  color: #6ee7b7;
  font-size: 0.9rem;
  font-weight: 500;
}

.waitlist-success.is-visible {
  display: flex;
}

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
  background: var(--dark);
  color: rgba(255, 255, 255, 0.7);
  padding: 64px 0 0;
}

.footer__grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1fr;
  gap: 48px;
  padding-bottom: 48px;
  border-bottom: 1px solid rgba(255,255,255,0.08);
}

.footer__brand-logo {
  font-family: var(--font-heading);
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--white);
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 12px;
}

.footer__brand-tagline {
  font-size: 0.875rem;
  line-height: 1.6;
  margin-bottom: 20px;
  color: rgba(255,255,255,0.55);
}

.footer__socials {
  display: flex;
  gap: 12px;
}

.footer__social-link {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-sm);
  background: rgba(255,255,255,0.07);
  border: 1px solid rgba(255,255,255,0.1);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  color: rgba(255,255,255,0.7);
  transition: all var(--transition);
  text-decoration: none;
}

.footer__social-link:hover {
  background: var(--primary);
  border-color: var(--primary);
  color: var(--white);
  transform: translateY(-2px);
}

.footer__col-title {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: rgba(255,255,255,0.5);
  margin-bottom: 20px;
}

.footer__links {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer__link {
  font-size: 0.875rem;
  color: rgba(255,255,255,0.6);
  transition: color var(--transition);
}

.footer__link:hover {
  color: var(--white);
}

.footer__bottom {
  padding: 20px 0;
  text-align: center;
}

.footer__copyright {
  font-size: 0.78rem;
  color: rgba(255,255,255,0.35);
  line-height: 1.7;
}

/* ============================================================
   INNER PAGES (privacy, support)
   ============================================================ */
.page-hero {
  padding: 140px 0 64px;
  background: linear-gradient(135deg, var(--gray-100), var(--white));
  border-bottom: 1px solid var(--gray-300);
}

.page-hero__title {
  font-family: var(--font-heading);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 700;
  color: var(--dark);
  margin-bottom: 12px;
}

.page-hero__meta {
  font-size: 0.9rem;
  color: var(--gray-500);
}

.page-content {
  padding: 64px 0 96px;
  max-width: 780px;
  margin: 0 auto;
}

.page-content h2 {
  font-family: var(--font-heading);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--dark);
  margin: 40px 0 12px;
}

.page-content h2:first-child {
  margin-top: 0;
}

.page-content p {
  font-size: 0.95rem;
  color: var(--gray-700);
  line-height: 1.8;
  margin-bottom: 16px;
}

.page-content ul {
  list-style: disc;
  padding-left: 24px;
  margin-bottom: 16px;
}

.page-content ul li {
  font-size: 0.95rem;
  color: var(--gray-700);
  line-height: 1.8;
  margin-bottom: 6px;
}

.page-content a {
  color: var(--primary);
  text-decoration: underline;
}

/* Support FAQ */
.faq-list {
  margin-bottom: 48px;
}

.faq-item {
  border: 1px solid var(--gray-300);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  overflow: hidden;
}

.faq-question {
  width: 100%;
  text-align: left;
  padding: 18px 24px;
  background: var(--white);
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--dark);
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 16px;
  transition: background var(--transition);
}

.faq-question:hover {
  background: var(--gray-100);
}

.faq-question__icon {
  font-size: 1.2rem;
  color: var(--primary);
  flex-shrink: 0;
  transition: transform var(--transition);
}

.faq-item.is-open .faq-question__icon {
  transform: rotate(45deg);
}

.faq-answer {
  display: none;
  padding: 0 24px 18px;
  font-size: 0.9rem;
  color: var(--gray-700);
  line-height: 1.75;
  background: var(--white);
}

.faq-item.is-open .faq-answer {
  display: block;
}

/* Contact form */
.contact-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

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

.form-group label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--gray-700);
}

.form-group input,
.form-group textarea {
  padding: 12px 16px;
  border: 1px solid var(--gray-300);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  color: var(--dark);
  transition: border-color var(--transition), box-shadow var(--transition);
  outline: none;
  background: var(--white);
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(95, 81, 251, 0.1);
}

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

.form-submit {
  align-self: flex-start;
  padding: 13px 32px;
  background: var(--primary);
  color: var(--white);
  border-radius: var(--radius-md);
  font-size: 0.95rem;
  font-weight: 600;
  transition: all var(--transition);
}

.form-submit:hover {
  background: var(--primary-dark);
  transform: translateY(-1px);
}

.form-success {
  display: none;
  padding: 16px 20px;
  background: rgba(16, 185, 129, 0.08);
  border: 1px solid rgba(16, 185, 129, 0.3);
  border-radius: var(--radius-md);
  color: #065f46;
  font-size: 0.9rem;
  font-weight: 500;
}

.form-success.is-visible {
  display: block;
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 1024px) {
  .hero__inner {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero__subtitle {
    margin: 0 auto 40px;
  }

  .hero__actions {
    justify-content: center;
  }

  .hero__social-proof {
    justify-content: center;
  }

  .hero__visual {
    display: none;
  }

  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .science-grid {
    grid-template-columns: 1fr;
    gap: 48px;
  }

  .science-cards {
    flex-direction: row;
  }

  .science-card {
    flex: 1;
  }

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

  .footer__brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 768px) {
  .nav__links {
    display: none;
  }

  .nav__hamburger {
    display: flex;
  }

  .hero {
    padding: 100px 0 60px;
  }

  .hero__h1 {
    font-size: 2.4rem;
  }

  .vs-section__grid {
    grid-template-columns: 1fr;
  }

  .vs-divider {
    order: -1;
  }

  .vs-divider__circle {
    margin: 0 auto;
  }

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

  .how-grid::before {
    display: none;
  }

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

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

  .demo__controls {
    flex-wrap: wrap;
    justify-content: center;
  }

  .demo__btn {
    flex: 1;
    justify-content: center;
    min-width: 100px;
  }

  .science-cards {
    flex-direction: column;
  }

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

  .waitlist-form {
    flex-direction: column;
  }

  .section {
    padding: 64px 0;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }

  .hero__h1 {
    font-size: 2rem;
  }

  .btn--large {
    padding: 14px 24px;
    font-size: 0.95rem;
  }

  .demo__card {
    height: 420px;
  }

  .download-section__buttons {
    flex-direction: column;
    align-items: center;
  }

  .hero__eyebrow {
    font-size: 0.75rem;
  }

  .section__title {
    font-size: 1.75rem;
  }
}