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

:root {
  --accent:  #4361ee;
  --accent2: #7209b7;
  --danger:  #f72585;
  --success: #06d6a0;
  --warning: #e9c46a;
  --info:    #4cc9f0;
  --bg:      #0a0a1a;
  --bg2:     #10102a;
  --surface: #16163a;
  --border:  rgba(255,255,255,.08);
  --text:    #e2e8f0;
  --muted:   #64748b;
  --sub:     #94a3b8;
  --radius:  12px;
}

html { scroll-behavior: smooth; }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  font-size: 16px;
}

a { color: var(--accent); text-decoration: none; }
code {
  background: var(--surface);
  padding: 2px 7px;
  border-radius: 5px;
  font-size: 13px;
  font-family: 'SF Mono', 'Fira Code', monospace;
}

/* ─── Nav ─────────────────────────────────────────────────────────────────── */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(10,10,26,.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 1100px; margin: 0 auto;
  padding: 0 24px;
  height: 60px;
  display: flex; align-items: center; justify-content: space-between;
}
.nav-logo {
  display: flex; align-items: center; gap: 10px;
  font-size: 16px; font-weight: 700;
}
.nav-cta {
  padding: 8px 20px;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: #fff;
  border-radius: 8px;
  font-size: 14px; font-weight: 600;
  transition: opacity .15s;
}
.nav-cta:hover { opacity: .88; color: #fff; }

/* ─── Hero ────────────────────────────────────────────────────────────────── */
.hero {
  max-width: 1100px; margin: 0 auto;
  padding: 80px 24px 60px;
  min-height: 0; /* prevent CLS from implicit height changes */
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}
.hero-badge {
  display: inline-block;
  background: rgba(67,97,238,.15);
  border: 1px solid rgba(67,97,238,.4);
  color: #a5b4fc;
  font-size: 12px; font-weight: 700;
  text-transform: uppercase; letter-spacing: .08em;
  padding: 4px 12px; border-radius: 20px;
  margin-bottom: 16px;
}
.hero-title {
  font-size: 52px; font-weight: 800;
  line-height: 1.1; letter-spacing: -.03em;
  margin-bottom: 20px;
}
.hero-accent {
  background: linear-gradient(135deg, var(--accent), var(--accent2), var(--danger));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-sub {
  font-size: 17px; color: var(--sub); line-height: 1.65;
  margin-bottom: 32px;
}
.hero-sub strong { color: var(--text); }
.hero-actions {
  display: flex; align-items: center; gap: 14px;
  margin-bottom: 16px;
}
.btn-primary {
  padding: 13px 28px;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: #fff; border-radius: 10px;
  font-size: 15px; font-weight: 700;
  transition: transform .15s, opacity .15s;
  box-shadow: 0 8px 24px rgba(67,97,238,.4);
}
.btn-primary:hover { transform: translateY(-2px); opacity: .92; color: #fff; }
.btn-ghost {
  padding: 13px 20px;
  color: var(--sub); font-size: 15px; font-weight: 500;
  border: 1px solid var(--border); border-radius: 10px;
  transition: color .15s, border-color .15s;
}
.btn-ghost:hover { color: var(--text); border-color: var(--accent); }
.btn-demo {
  padding: 13px 20px;
  color: var(--muted); font-size: 14px; font-weight: 500;
  transition: color .15s;
}
.btn-demo:hover { color: var(--accent); }
.hero-note { font-size: 12px; color: var(--muted); }

/* ─── Preview mockup ──────────────────────────────────────────────────────── */
.hero-preview {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 14px;
  overflow: hidden;
  box-shadow: 0 32px 80px rgba(0,0,0,.6);
}
.preview-bar {
  background: var(--surface);
  padding: 10px 14px;
  display: flex; align-items: center; gap: 6px;
  border-bottom: 1px solid var(--border);
}
.dot { width: 11px; height: 11px; border-radius: 50%; }
.dot.red    { background: #ff5f57; }
.dot.yellow { background: #febc2e; }
.dot.green  { background: #28c840; }
.preview-url {
  margin-left: 8px; font-size: 11px; color: var(--muted);
  flex: 1; text-align: center;
}
.preview-body {
  display: flex; min-height: 320px;
}
.preview-sidebar {
  width: 110px; flex-shrink: 0;
  background: var(--bg);
  border-right: 1px solid var(--border);
  padding: 12px 8px;
  display: flex; flex-direction: column; gap: 3px;
  font-size: 11px;
}
.preview-nav-item {
  padding: 6px 8px; border-radius: 5px;
  color: var(--muted); cursor: default;
}
.preview-nav-item.active {
  background: rgba(67,97,238,.2); color: var(--text);
}
.preview-sep { height: 1px; background: var(--border); margin: 6px 0; }
.preview-course-dot {
  display: flex; align-items: center; gap: 5px;
  font-size: 10px; color: var(--sub);
  padding: 3px 6px;
}
.preview-course-dot::before {
  content: '';
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--c);
  flex-shrink: 0;
}
.preview-main {
  flex: 1; padding: 12px; display: flex; flex-direction: column; gap: 6px;
}
.preview-section-label {
  font-size: 10px; font-weight: 700; text-transform: uppercase;
  letter-spacing: .07em; padding: 4px 0 2px;
}
.preview-section-label.overdue { color: var(--danger); }
.preview-section-label.today   { color: var(--warning); }
.preview-section-label.week    { color: var(--accent); }
.preview-card {
  background: var(--surface); border-radius: 6px;
  padding: 7px 10px 7px 14px;
  display: flex; align-items: center; gap: 8px;
  font-size: 11px;
  position: relative; overflow: hidden;
}
.preview-stripe {
  position: absolute; left: 0; top: 0; bottom: 0;
  width: 3px;
}
.preview-name { flex: 1; font-weight: 500; }
.preview-badge {
  font-size: 9px; font-weight: 700;
  padding: 2px 6px; border-radius: 20px; color: #fff;
}
.preview-badge.syllabus-badge {
  background: rgba(233,196,106,.2);
  color: var(--warning);
  border: 1px solid rgba(233,196,106,.3);
}
.preview-due { font-size: 10px; font-weight: 600; color: var(--muted); }
.preview-due.overdue { color: var(--danger); }
.preview-due.today   { color: var(--warning); }
.overdue-card { opacity: .75; }

/* ─── Section shared ──────────────────────────────────────────────────────── */
.section-inner { max-width: 1100px; margin: 0 auto; padding: 80px 24px; }
.section-title {
  font-size: 36px; font-weight: 800; letter-spacing: -.02em;
  text-align: center; margin-bottom: 12px;
}
.section-sub {
  text-align: center; font-size: 17px; color: var(--sub);
  margin-bottom: 48px;
}

/* ─── Features ────────────────────────────────────────────────────────────── */
.features { background: var(--bg2); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.features-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px;
}
.feature-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  transition: border-color .2s, transform .2s;
}
.feature-card:hover { border-color: var(--accent); transform: translateY(-3px); }
.feature-icon {
  width: 44px; height: 44px;
  border-radius: 10px;
  display: flex; align-items: center; justify-content: center;
  margin-bottom: 16px;
}
.feature-card h3 { font-size: 16px; font-weight: 700; margin-bottom: 8px; }
.feature-card p  { font-size: 14px; color: var(--sub); line-height: 1.6; }

/* ─── How it works ────────────────────────────────────────────────────────── */
.steps {
  display: flex; align-items: flex-start; gap: 16px;
}
.step {
  flex: 1;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  text-align: center;
}
.step-num {
  width: 40px; height: 40px;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 18px; font-weight: 800; color: #fff;
  margin: 0 auto 16px;
}
.step h3 { font-size: 16px; font-weight: 700; margin-bottom: 8px; }
.step p  { font-size: 14px; color: var(--sub); line-height: 1.6; }
.step-arrow { font-size: 28px; color: var(--muted); padding-top: 40px; flex-shrink: 0; }

/* ─── Pricing ─────────────────────────────────────────────────────────────── */
.pricing { background: var(--bg2); border-top: 1px solid var(--border); }
.pricing-card {
  max-width: 400px; margin: 0 auto;
  background: var(--surface);
  border: 1px solid rgba(67,97,238,.4);
  border-radius: 18px;
  padding: 36px 32px;
  text-align: center;
  box-shadow: 0 0 60px rgba(67,97,238,.15);
}
.pricing-top { margin-bottom: 24px; }
.pricing-price {
  font-size: 64px; font-weight: 900;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
}
.pricing-period { font-size: 14px; color: var(--muted); margin-top: 4px; }
.pricing-features {
  list-style: none;
  margin-bottom: 28px;
  display: flex; flex-direction: column; gap: 10px;
  text-align: left;
}
.pricing-features li { font-size: 15px; color: var(--sub); }
.pricing-features li::first-child { color: var(--success); }
.btn-buy {
  display: block;
  padding: 14px;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: #fff; border-radius: 10px;
  font-size: 16px; font-weight: 700;
  transition: transform .15s, opacity .15s;
  box-shadow: 0 8px 24px rgba(67,97,238,.4);
  margin-bottom: 14px;
}
.btn-buy:hover { transform: translateY(-2px); opacity: .9; color: #fff; }
.pricing-note { font-size: 12px; color: var(--muted); line-height: 1.6; }

/* ─── Footer ──────────────────────────────────────────────────────────────── */
.footer {
  border-top: 1px solid var(--border);
  padding: 28px 24px;
}
.footer .section-inner { padding: 0; max-width: 1100px; margin: 0 auto; display: flex; align-items: center; justify-content: space-between; }
.footer-logo {
  display: flex; align-items: center; gap: 8px;
  font-size: 14px; font-weight: 700;
}
.footer-note { font-size: 12px; color: var(--muted); }
.footer-links { display: flex; align-items: center; gap: 8px; font-size: 12px; color: var(--muted); }
.footer-links a { color: var(--muted); text-decoration: none; }
.footer-links a:hover { color: var(--text); }

/* ─── Responsive ──────────────────────────────────────────────────────────── */
@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; gap: 40px; }
  .hero-title { font-size: 38px; }
  .features-grid { grid-template-columns: 1fr 1fr; }
  .steps { flex-direction: column; }
  .step-arrow { display: none; }
}
@media (max-width: 600px) {
  .hero-title { font-size: 30px; }
  .hero-actions { flex-direction: column; }
  .features-grid { grid-template-columns: 1fr; }
  .footer .section-inner { flex-direction: column; gap: 8px; text-align: center; }
}