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

:root {
  --bg: #FFF8F0;
  --fg: #1A1A1A;
  --accent: #1B4332;
  --amber: #D97706;
  --amber-light: #FEF3C7;
  --slate: #6B7280;
  --slate-light: #F3F4F6;
  --surface: #FFFFFF;
  --border: #E5E7EB;
  --font-display: 'Playfair Display', Georgia, serif;
  --font-body: 'DM Sans', system-ui, sans-serif;
}

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--fg);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

/* ===== TYPOGRAPHY ===== */
section { padding: 80px 24px; }

.section-eyebrow {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--amber);
  margin-bottom: 12px;
}

.section-heading {
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 42px);
  font-weight: 700;
  line-height: 1.2;
  color: var(--fg);
  max-width: 600px;
}

.section-heading em {
  font-style: italic;
  color: var(--accent);
}

/* ===== NAV ===== */
.nav {
  padding: 20px 32px;
  border-bottom: 1px solid var(--border);
  background: var(--bg);
}

.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 12px;
}

.nav-logo {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  color: var(--fg);
}

.nav-tagline {
  font-size: 13px;
  color: var(--slate);
  padding-left: 12px;
  border-left: 1px solid var(--border);
}

.nav-demo-link {
  font-size: 13px;
  font-weight: 500;
  color: var(--accent);
  text-decoration: none;
  padding: 6px 14px;
  border: 1.5px solid var(--accent);
  border-radius: 8px;
  transition: background 0.15s, color 0.15s;
}
.nav-demo-link:hover { background: var(--accent); color: #fff; }

.nav-cta {
  font-size: 13px;
  font-weight: 600;
  color: #fff;
  text-decoration: none;
  padding: 6px 16px;
  background: var(--accent);
  border-radius: 8px;
  transition: background 0.15s;
}
.nav-cta:hover { background: #153729; }

/* ===== HERO ===== */
.hero { padding: 80px 24px 80px; }

.hero-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.hero-eyebrow {
  font-size: 13px;
  font-weight: 500;
  color: var(--slate);
  letter-spacing: 0.04em;
  margin-bottom: 16px;
}

.hero-headline {
  font-family: var(--font-display);
  font-size: clamp(36px, 5vw, 56px);
  font-weight: 900;
  line-height: 1.1;
  color: var(--fg);
  margin-bottom: 20px;
}

.hero-headline em {
  font-style: italic;
  color: var(--accent);
}

.hero-sub {
  font-size: 18px;
  color: var(--slate);
  line-height: 1.65;
  max-width: 480px;
  margin-bottom: 28px;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.meta-badge {
  font-size: 12px;
  font-weight: 500;
  background: var(--accent);
  color: #fff;
  padding: 5px 12px;
  border-radius: 20px;
}

/* PRODUCT CARD */
.hero-visual { display: flex; justify-content: center; }

.product-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  width: 100%;
  max-width: 420px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.08), 0 4px 16px rgba(0,0,0,0.04);
  overflow: hidden;
}

.card-header {
  background: var(--slate-light);
  padding: 12px 16px;
  display: flex;
  align-items: center;
  gap: 8px;
  border-bottom: 1px solid var(--border);
}

.card-dot { width: 10px; height: 10px; border-radius: 50%; }
.dot-red { background: #FF5F57; }
.dot-yellow { background: #FFBD2E; }
.dot-green { background: #28C840; }

.card-title {
  font-size: 12px;
  color: var(--slate);
  font-weight: 500;
  margin-left: auto;
  margin-right: auto;
}

.card-body { padding: 20px; display: flex; flex-direction: column; gap: 20px; }

.card-section { display: flex; flex-direction: column; gap: 8px; }

.section-label {
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--amber);
}

.section-text {
  font-size: 13px;
  line-height: 1.55;
  color: var(--slate);
  background: var(--bg);
  border-left: 3px solid var(--amber);
  padding: 10px 12px;
  border-radius: 0 8px 8px 0;
}

.flashcard-stack { display: flex; flex-direction: column; gap: 8px; }

.flashcard {
  background: var(--accent);
  color: #fff;
  border-radius: 10px;
  padding: 12px 14px;
  font-size: 12px;
}

.flashcard-alt { background: var(--amber); }

.fc-q { font-weight: 600; margin-bottom: 6px; }
.fc-a { opacity: 0.85; font-size: 11px; line-height: 1.45; }

.exam-schedule { display: flex; flex-direction: column; gap: 6px; }

.schedule-row {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  font-size: 11px;
  padding: 8px 10px;
  background: var(--bg);
  border-radius: 8px;
}

.day-label {
  font-weight: 600;
  color: var(--accent);
  white-space: nowrap;
  min-width: 80px;
}

.day-tasks { color: var(--slate); line-height: 1.4; }

/* ===== HOW IT WORKS ===== */
.hiw { background: var(--surface); }

.hiw-inner {
  max-width: 1100px;
  margin: 0 auto;
}

.hiw-steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 48px;
  margin-top: 56px;
}

.hiw-step { display: flex; flex-direction: column; gap: 16px; }

.step-num {
  font-family: var(--font-display);
  font-size: 48px;
  font-weight: 900;
  color: var(--amber-light);
  line-height: 1;
  -webkit-text-stroke: 1.5px var(--amber);
}

.step-content h3 {
  font-size: 18px;
  font-weight: 600;
  color: var(--fg);
  margin-bottom: 8px;
}

.step-content p { font-size: 15px; color: var(--slate); line-height: 1.6; }

/* ===== FEATURES ===== */
.features { background: var(--bg); }

.features-inner { max-width: 1100px; margin: 0 auto; }

.feature-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
  margin-top: 56px;
}

.feature-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 32px;
  transition: box-shadow 0.2s;
}

.feature-card:hover { box-shadow: 0 8px 32px rgba(0,0,0,0.07); }

.feat-icon {
  width: 52px;
  height: 52px;
  background: var(--amber-light);
  border-radius: 12px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--amber);
  margin-bottom: 20px;
}

.feature-card h3 {
  font-size: 18px;
  font-weight: 600;
  color: var(--fg);
  margin-bottom: 10px;
}

.feature-card p { font-size: 15px; color: var(--slate); line-height: 1.6; }

/* ===== DIFFERENTIATOR ===== */
.diff { background: var(--accent); color: #fff; }

.diff-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.diff .section-eyebrow { color: #86EFAC; }

.diff-heading {
  font-family: var(--font-display);
  font-size: clamp(24px, 3vw, 36px);
  font-weight: 700;
  line-height: 1.3;
  color: #fff;
  margin-bottom: 20px;
  max-width: 480px;
}

.diff-heading em { font-style: italic; color: #86EFAC; }

.diff-body {
  font-size: 16px;
  color: rgba(255,255,255,0.75);
  line-height: 1.65;
  margin-bottom: 28px;
}

.diff-points { display: flex; flex-direction: column; gap: 14px; }

.diff-point {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  font-size: 15px;
  color: rgba(255,255,255,0.9);
}

.point-icon {
  width: 24px;
  height: 24px;
  background: #86EFAC;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
  flex-shrink: 0;
  margin-top: 1px;
}

/* DEPTH WIDGET */
.depth-widget {
  background: rgba(255,255,255,0.08);
  border: 1px solid rgba(255,255,255,0.15);
  border-radius: 16px;
  padding: 28px;
}

.depth-label {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: rgba(255,255,255,0.5);
  margin-bottom: 20px;
}

.depth-track { position: relative; margin-bottom: 28px; }

.depth-marker {
  position: absolute;
  top: -30px;
  transform: translateX(-50%);
}

.depth-tag {
  font-size: 10px;
  font-weight: 600;
  color: rgba(255,255,255,0.5);
  white-space: nowrap;
}

.depth-marker.active .depth-tag { color: #86EFAC; font-weight: 700; }

.depth-line {
  height: 4px;
  background: rgba(255,255,255,0.2);
  border-radius: 2px;
  margin-top: 20px;
}

.depth-fill {
  height: 100%;
  background: #86EFAC;
  border-radius: 2px;
}

.depth-response {
  background: rgba(255,255,255,0.06);
  border-radius: 12px;
  padding: 16px;
}

.response-label {
  font-size: 11px;
  font-weight: 600;
  color: rgba(255,255,255,0.5);
  margin-bottom: 8px;
}

.response-text {
  font-size: 13px;
  color: rgba(255,255,255,0.85);
  line-height: 1.6;
  font-style: italic;
}

/* ===== PRICING ===== */
.pricing { background: var(--surface); }

.pricing-inner { max-width: 1100px; margin: 0 auto; text-align: center; }

.pricing-toggle {
  display: inline-flex;
  align-items: center;
  gap: 14px;
  margin: 32px 0 48px;
  font-size: 14px;
  color: var(--slate);
}

.toggle-label { font-weight: 500; }

.toggle-track {
  width: 44px;
  height: 24px;
  background: var(--slate-light);
  border: 1px solid var(--border);
  border-radius: 12px;
  position: relative;
}

.toggle-thumb {
  width: 18px;
  height: 18px;
  background: var(--accent);
  border-radius: 50%;
  position: absolute;
  top: 2px;
  right: 3px;
}

.toggle-semester { color: var(--fg); }

.save-badge {
  background: var(--amber);
  color: #fff;
  font-size: 10px;
  font-weight: 700;
  padding: 2px 7px;
  border-radius: 10px;
  margin-left: 6px;
}

.plan-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  text-align: left;
}

.plan-card {
  background: var(--bg);
  border: 2px solid var(--border);
  border-radius: 20px;
  padding: 32px;
  position: relative;
}

.plan-pro {
  border-color: var(--accent);
  background: var(--surface);
}

.plan-semester {
  border-color: var(--amber);
  background: var(--surface);
}

.pro-badge, .semester-badge {
  position: absolute;
  top: -12px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 11px;
  font-weight: 700;
  padding: 4px 14px;
  border-radius: 12px;
  white-space: nowrap;
}

.pro-badge { background: var(--accent); color: #fff; }
.semester-badge { background: var(--amber); color: #fff; }

.plan-name {
  font-size: 16px;
  font-weight: 700;
  color: var(--fg);
  margin-bottom: 12px;
}

.plan-price {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin-bottom: 14px;
}

.price-amount {
  font-family: var(--font-display);
  font-size: 40px;
  font-weight: 700;
  color: var(--fg);
}

.price-period { font-size: 14px; color: var(--slate); }

.plan-desc { font-size: 13px; color: var(--slate); line-height: 1.55; margin-bottom: 20px; }

.plan-features { list-style: none; display: flex; flex-direction: column; gap: 10px; }

.plan-features li {
  font-size: 14px;
  color: var(--fg);
  display: flex;
  gap: 10px;
  align-items: flex-start;
}

.plan-features li::before {
  content: '';
  width: 18px;
  height: 18px;
  min-width: 18px;
  background: var(--amber);
  border-radius: 50%;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='white' stroke-width='3' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='20 6 9 17 4 12'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: center;
  margin-top: 1px;
}

.pricing-footnote {
  font-size: 13px;
  color: var(--slate);
  margin-top: 32px;
}

/* ===== CLOSING ===== */
.closing {
  background: var(--bg);
  text-align: center;
  padding: 100px 24px;
}

.closing-inner { max-width: 800px; margin: 0 auto; }

.closing-eyebrow {
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.04em;
  color: var(--slate);
  margin-bottom: 20px;
}

.closing-headline {
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 48px);
  font-weight: 700;
  line-height: 1.25;
  color: var(--fg);
  margin-bottom: 24px;
}

.closing-body {
  font-size: 18px;
  color: var(--slate);
  line-height: 1.7;
  max-width: 560px;
  margin: 0 auto;
}

.closing-actions {
  display: flex;
  gap: 14px;
  justify-content: center;
  align-items: center;
  margin-top: 32px;
  flex-wrap: wrap;
}

.btn-primary {
  display: inline-block;
  padding: 14px 32px;
  background: var(--accent);
  color: #fff;
  border-radius: 12px;
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  transition: background 0.2s;
  font-family: var(--font-body);
}
.btn-primary:hover { background: #153729; }

.btn-ghost-dark {
  display: inline-block;
  padding: 14px 28px;
  border: 2px solid var(--border);
  color: var(--fg);
  border-radius: 12px;
  font-size: 15px;
  font-weight: 600;
  text-decoration: none;
  transition: border-color 0.2s;
  font-family: var(--font-body);
}
.btn-ghost-dark:hover { border-color: var(--accent); color: var(--accent); }

/* ===== FOOTER ===== */
.footer {
  background: var(--fg);
  color: rgba(255,255,255,0.7);
  padding: 48px 24px;
}

.footer-inner {
  max-width: 1100px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.footer-logo {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  color: #fff;
}

.footer-tagline { font-size: 13px; margin-top: 6px; }

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
}

.footer-links a {
  font-size: 13px;
  color: rgba(255,255,255,0.6);
  text-decoration: none;
  transition: color 0.2s;
}

.footer-links a:hover { color: #fff; }

.footer-copy {
  font-size: 12px;
  color: rgba(255,255,255,0.4);
  line-height: 1.6;
  border-top: 1px solid rgba(255,255,255,0.1);
  padding-top: 24px;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 900px) {
  .hero-inner,
  .diff-inner { grid-template-columns: 1fr; gap: 40px; }

  .hiw-steps { grid-template-columns: 1fr; gap: 36px; }
  .feature-grid { grid-template-columns: 1fr; }
  .plan-grid { grid-template-columns: 1fr; max-width: 400px; margin: 0 auto; }

  .hero-visual { order: -1; }
  .product-card { max-width: 100%; }

  .diff-visual { order: -1; }
}

@media (max-width: 600px) {
  section { padding: 60px 20px; }
  .nav { padding: 16px 20px; }
  .nav-tagline { display: none; }
  .plan-grid { max-width: 100%; }
}