@import url('https://fonts.googleapis.com/css2?family=Sora:wght@400;600;700&family=Inter:wght@400;500&display=swap');

:root {
  --navy: #1a237e;
  --navy-deep: #0d1257;
  --navy-light: #283593;
  --cyan: #00bcd4;
  --cyan-light: #4dd0e1;
  --cyan-glow: #e0f7fa;
  --coral: #f4806a;
  --coral-dark: #e64a19;
  --white: #ffffff;
  --off-white: #f5f8ff;
  --text-dark: #0d1257;
  --text-muted: #546e7a;
  --border: #e3eaf5;
  --card-bg: #ffffff;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 22px;
  --shadow-soft: 0 4px 24px rgba(26,35,126,0.08), 0 1px 4px rgba(0,188,212,0.06);
  --shadow-card: 0 2px 16px rgba(26,35,126,0.10);
}

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

body {
  font-family: 'Inter', sans-serif;
  background: var(--off-white);
  color: var(--text-dark);
  min-height: 100vh;
  line-height: 1.7;
}

main {
  max-width: 860px;
  margin: 0 auto;
  padding: 2.5rem 1.5rem 4rem;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* ── Title Block ── */
main > div:first-child {
  background: linear-gradient(120deg, var(--navy-deep) 0%, var(--navy-light) 70%, #1565c0 100%);
  border-radius: var(--radius-lg);
  padding: 2.2rem 2rem 2rem;
  position: relative;
  overflow: hidden;
}
main > div:first-child::before {
  content: '';
  position: absolute;
  top: -30px; right: -30px;
  width: 140px; height: 140px;
  background: rgba(0,188,212,0.18);
  border-radius: 50%;
}
main > div:first-child::after {
  content: '';
  position: absolute;
  bottom: -20px; left: 60px;
  width: 80px; height: 80px;
  background: rgba(244,128,106,0.15);
  border-radius: 50%;
}
main > div:first-child h1 {
  font-family: 'Sora', sans-serif;
  font-size: clamp(1.05rem, 3vw, 1.45rem);
  font-weight: 700;
  color: var(--white);
  letter-spacing: 0.01em;
  line-height: 1.4;
  position: relative;
  z-index: 1;
}
main > div:first-child h1::after {
  content: '';
  display: block;
  margin-top: 14px;
  width: 52px;
  height: 4px;
  border-radius: 99px;
  background: var(--cyan);
}

/* ── Week Label ── */
main > div:nth-child(2) {
  display: flex;
  align-items: center;
}
main > div:nth-child(2) h2 {
  font-family: 'Sora', sans-serif;
  font-size: clamp(0.95rem, 2.5vw, 1.15rem);
  font-weight: 600;
  color: var(--navy);
  background: var(--cyan-glow);
  border-left: 4px solid var(--cyan);
  padding: 0.65rem 1.2rem;
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  width: 100%;
}

/* ── Description Card ── */
main > div:nth-child(3) {
  background: var(--card-bg);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  padding: 1.5rem 1.6rem;
  box-shadow: var(--shadow-card);
  position: relative;
}
main > div:nth-child(3)::before {
  content: 'Lesson Overview';
  display: block;
  font-family: 'Sora', sans-serif;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--coral);
  margin-bottom: 0.6rem;
}
main > div:nth-child(3) p {
  font-size: 0.97rem;
  color: var(--text-muted);
  line-height: 1.8;
}

/* ── Resources Section ── */
main > div:last-child {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  padding: 1.8rem 1.8rem 2rem;
  box-shadow: var(--shadow-soft);
}
main > div:last-child > div h2 {
  font-family: 'Sora', sans-serif;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--navy);
  margin-bottom: 1.2rem;
  display: flex;
  align-items: center;
  gap: 0.55rem;
}
main > div:last-child > div h2::before {
  content: '';
  display: inline-block;
  width: 10px; height: 10px;
  border-radius: 50%;
  background: var(--coral);
  flex-shrink: 0;
}

ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.65rem;
}
li:empty { display: none; }

li a {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  text-decoration: none;
  background: var(--off-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1.1rem;
  font-size: 0.93rem;
  font-weight: 500;
  color: var(--navy);
  transition: all 0.22s ease;
  position: relative;
  overflow: hidden;
}
li a::before {
  content: '';
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 3px;
  background: var(--cyan);
  border-radius: 3px 0 0 3px;
  opacity: 0;
  transition: opacity 0.2s;
}
li a:hover {
  background: var(--cyan-glow);
  border-color: var(--cyan-light);
  color: var(--navy-deep);
  transform: translateX(3px);
  box-shadow: 0 2px 12px rgba(0,188,212,0.13);
}
li a:hover::before { opacity: 1; }

br { display: none; }

/* ── Responsive ── */
@media (max-width: 600px) {
  main { padding: 1.2rem 0.9rem 3rem; gap: 1.1rem; }
  main > div:first-child { padding: 1.5rem 1.2rem; }
  main > div:last-child { padding: 1.3rem 1.1rem 1.5rem; }
  li a { font-size: 0.88rem; padding: 0.65rem 0.9rem; }
}