/* === RESET & BASE === */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --bg: #F7F3EC;
  --fg: #0D0A08;
  --teal: #0D4F5C;
  --teal-light: #1A7280;
  --cream: #F7F3EC;
  --orange: #E85D04;
  --orange-light: #FF7A30;
  --cream-dark: #EDE7DC;
  --white: #FFFFFF;
}
html { scroll-behavior: smooth; }
body {
  font-family: 'DM Sans', system-ui, sans-serif;
  background: var(--bg);
  color: var(--fg);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3 { font-family: 'Syne', system-ui, sans-serif; font-weight: 700; }

/* === NAV === */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(247, 243, 236, 0.88);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid rgba(13, 79, 92, 0.08);
}
.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  padding: 16px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  font-family: 'Syne', sans-serif;
  font-weight: 800;
  font-size: 20px;
  color: var(--teal);
  letter-spacing: -0.5px;
}
.nav-tag {
  font-size: 13px;
  color: var(--teal-light);
  font-weight: 500;
  background: rgba(13, 79, 92, 0.07);
  padding: 4px 12px;
  border-radius: 100px;
}

/* === HERO === */
.hero {
  padding: 80px 32px 100px;
  background: var(--bg);
  overflow: hidden;
}
.hero-inner {
  max-width: 1100px;
  margin: 0 auto;
}
.hero-badge {
  display: inline-block;
  background: var(--teal);
  color: var(--cream);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 6px 14px;
  border-radius: 100px;
  margin-bottom: 28px;
}
.hero-headline {
  font-size: clamp(52px, 9vw, 96px);
  font-weight: 800;
  line-height: 1.0;
  letter-spacing: -3px;
  color: var(--fg);
  margin-bottom: 24px;
}
.hero-sub {
  font-size: 17px;
  color: rgba(13, 10, 8, 0.65);
  max-width: 480px;
  line-height: 1.65;
  margin-bottom: 52px;
}

/* === FLASHCAED STACK === */
.hero-cards {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 16px;
  margin-bottom: 56px;
}
.flashcard {
  border-radius: 18px;
  padding: 26px 24px;
  position: relative;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08), 0 12px 32px rgba(0,0,0,0.06);
  transform: rotate(var(--rotate, 0deg));
}
.flashcard-1 {
  background: var(--orange);
  --rotate: -2.5deg;
  transform: rotate(-2.5deg);
}
.flashcard-2 {
  background: var(--teal);
  --rotate: 0.5deg;
  transform: rotate(0.5deg);
}
.flashcard-3 {
  background: #F4A261;
  --rotate: 2deg;
  transform: rotate(2deg);
}
.fc-tag {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: rgba(255,255,255,0.7);
  margin-bottom: 16px;
}
.fc-q {
  font-family: 'Syne', sans-serif;
  font-size: 17px;
  font-weight: 600;
  color: var(--white);
  line-height: 1.4;
  margin-bottom: 12px;
}
.fc-hint {
  font-size: 12px;
  color: rgba(255,255,255,0.55);
  font-style: italic;
}

/* === STAT ROW === */
.hero-stat-row {
  display: flex;
  align-items: center;
  gap: 32px;
}
.stat {
  display: flex;
  flex-direction: column;
}
.stat-num {
  font-family: 'Syne', sans-serif;
  font-size: 28px;
  font-weight: 800;
  color: var(--teal);
  line-height: 1;
  margin-bottom: 4px;
}
.stat-label {
  font-size: 12px;
  color: rgba(13, 10, 8, 0.45);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.stat-divider {
  width: 1px;
  height: 32px;
  background: rgba(13, 79, 92, 0.15);
}

/* === SECTION SHARED === */
.section-label {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--orange);
  margin-bottom: 16px;
}
.section-headline {
  font-size: clamp(36px, 5.5vw, 60px);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -2px;
  color: var(--fg);
  margin-bottom: 48px;
}
.section-headline.light { color: var(--cream); }

/* === MANIFEST === */
.manifest {
  background: var(--teal);
  padding: 100px 32px;
}
.manifest-inner {
  max-width: 1100px;
  margin: 0 auto;
}
.manifest .section-label { color: var(--orange-light); }
.manifest-headline {
  font-size: clamp(32px, 5vw, 56px);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -2px;
  color: var(--cream);
  margin-bottom: 32px;
}
.manifest-body {
  font-size: 17px;
  color: rgba(247, 243, 236, 0.75);
  max-width: 560px;
  line-height: 1.7;
  margin-bottom: 16px;
}
.manifest-body:last-child { margin-bottom: 0; }

/* === SEMESTER === */
.semester {
  padding: 100px 32px;
  background: var(--cream);
}
.semester-inner {
  max-width: 1100px;
  margin: 0 auto;
}
.sem-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
}
.sem-card {
  background: var(--white);
  border-radius: 16px;
  padding: 28px 24px;
  border: 1px solid rgba(13, 79, 92, 0.08);
  box-shadow: 0 1px 4px rgba(0,0,0,0.04);
}
.sem-num {
  font-family: 'Syne', sans-serif;
  font-size: 32px;
  font-weight: 800;
  color: var(--orange);
  margin-bottom: 8px;
}
.sem-title {
  font-family: 'Syne', sans-serif;
  font-size: 16px;
  font-weight: 700;
  color: var(--teal);
  margin-bottom: 10px;
  line-height: 1.3;
}
.sem-topics {
  font-size: 13px;
  color: rgba(13, 10, 8, 0.55);
  line-height: 1.5;
}

/* === FEATURES === */
.features {
  background: var(--cream-dark);
  padding: 100px 32px;
}
.features-inner {
  max-width: 1100px;
  margin: 0 auto;
}
.feat-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}
.feat-card {
  background: var(--white);
  border-radius: 16px;
  padding: 32px;
  border: 1px solid rgba(13, 79, 92, 0.06);
}
.feat-icon {
  width: 52px;
  height: 52px;
  background: var(--teal);
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--cream);
  margin-bottom: 20px;
}
.feat-title {
  font-family: 'Syne', sans-serif;
  font-size: 19px;
  font-weight: 700;
  color: var(--teal);
  margin-bottom: 10px;
}
.feat-body {
  font-size: 15px;
  color: rgba(13, 10, 8, 0.6);
  line-height: 1.65;
}

/* === PROOF === */
.proof {
  padding: 100px 32px;
  background: var(--cream);
}
.proof-inner {
  max-width: 1100px;
  margin: 0 auto;
}
.proof-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}
.proof-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 22px 24px;
  border-radius: 14px;
  border: 1px solid rgba(13, 79, 92, 0.08);
}
.proof-item:has(.proof-highlight) { background: var(--teal); border-color: var(--teal); }
.proof-cross, .proof-check {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.proof-cross { background: rgba(232, 93, 4, 0.12); color: var(--orange); }
.proof-check { background: rgba(247, 243, 236, 0.15); color: var(--cream); }
.proof-text { font-size: 15px; color: rgba(13, 10, 8, 0.65); line-height: 1.5; }
.proof-item:has(.proof-highlight) .proof-text { color: var(--cream); }

/* === CLOSING === */
.closing { background: var(--teal); padding: 100px 32px; }
.closing-inner { max-width: 1100px; margin: 0 auto; }
.closing-teal { max-width: 680px; }
.closing-headline {
  font-size: clamp(36px, 5vw, 64px);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -2px;
  color: var(--cream);
  margin-bottom: 28px;
}
.closing-body {
  font-size: 17px;
  color: rgba(247, 243, 236, 0.75);
  line-height: 1.7;
  margin-bottom: 16px;
}
.closing-body:last-child { color: rgba(247, 243, 236, 0.45); font-style: italic; }

/* === FOOTER === */
.footer {
  background: var(--fg);
  padding: 48px 32px;
}
.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  text-align: center;
}
.footer-logo {
  font-family: 'Syne', sans-serif;
  font-size: 24px;
  font-weight: 800;
  color: var(--cream);
  margin-bottom: 10px;
}
.footer-tagline {
  font-size: 14px;
  color: rgba(247, 243, 236, 0.45);
  margin-bottom: 24px;
}
.footer-copy {
  font-size: 12px;
  color: rgba(247, 243, 236, 0.25);
}

/* === MOBILE === */
@media (max-width: 768px) {
  .hero { padding: 48px 20px 64px; }
  .hero-headline { letter-spacing: -1.5px; }
  .hero-cards { grid-template-columns: 1fr; gap: 12px; }
  .flashcard { transform: none !important; }
  .hero-stat-row { gap: 20px; }
  .sem-grid { grid-template-columns: 1fr 1fr; }
  .feat-grid { grid-template-columns: 1fr; }
  .proof-grid { grid-template-columns: 1fr; }
  .manifest, .semester, .features, .proof, .closing { padding: 64px 20px; }
  .section-headline { letter-spacing: -1px; }
  .nav-inner { padding: 14px 20px; }
  .sem-grid > .sem-card:nth-child(n+5) { grid-column: span 2; }
}
@media (max-width: 480px) {
  .sem-grid { grid-template-columns: 1fr; }
  .sem-grid > .sem-card:nth-child(n+5) { grid-column: span 1; }
}