:root {
  --ink: #202522;
  --muted: #68716b;
  --line: #e4e8e3;
  --paper: #fbfcfa;
  --surface: #f2f5f0;
  --accent: #496b57;
  --accent-dark: #2f4f3b;
  --max-width: 1120px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--paper); color: var(--ink); font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; line-height: 1.65; }
a { color: inherit; }
.site-header { max-width: var(--max-width); margin: 0 auto; padding: 26px 28px; display: flex; align-items: center; justify-content: space-between; gap: 28px; border-bottom: 1px solid var(--line); }
.brand { font-size: 1.08rem; font-weight: 750; letter-spacing: -.035em; text-decoration: none; white-space: nowrap; }
.main-nav { display: flex; flex-wrap: wrap; align-items: center; justify-content: flex-end; gap: 9px 22px; }
.main-nav a { color: var(--muted); text-decoration: none; font-size: .86rem; transition: color .15s ease; }
.main-nav a:hover, .main-nav a.active { color: var(--accent-dark); }
.main-nav a.active { font-weight: 700; }
.nav-break { white-space: nowrap; }
.home-main, .content-main { max-width: var(--max-width); margin: 0 auto; padding: 0 28px; }
.intro { max-width: 800px; padding: 92px 0 76px; }
.eyebrow { margin: 0 0 15px; color: var(--accent); font-size: .72rem; font-weight: 750; letter-spacing: .15em; }
h1, h2, h3, p { margin-top: 0; }
h1 { font-size: clamp(2.65rem, 6vw, 4.6rem); line-height: 1.06; letter-spacing: -.065em; margin-bottom: 23px; font-weight: 720; }
.intro-copy { max-width: 720px; color: #4f5952; font-size: clamp(1.05rem, 2vw, 1.23rem); line-height: 1.8; }
.contact-links { display: flex; align-items: center; gap: 14px; margin-top: 28px; color: var(--accent); font-size: .94rem; }
.contact-links a { text-decoration-thickness: 1px; text-underline-offset: 4px; }
.explore { padding: 54px 0 96px; border-top: 1px solid var(--line); }
.section-heading { display: flex; flex-wrap: wrap; align-items: baseline; justify-content: space-between; gap: 10px 30px; margin-bottom: 28px; }
.section-heading .eyebrow { margin-bottom: 0; }
.section-heading h2 { max-width: 600px; font-size: clamp(1.5rem, 3vw, 2.15rem); letter-spacing: -.045em; margin-bottom: 0; line-height: 1.25; }
.subject-grid, .module-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.subject-card, .module-card { display: flex; flex-direction: column; align-items: flex-start; text-decoration: none; border: 1px solid var(--line); background: #fff; border-radius: 12px; padding: 27px 28px; min-height: 205px; transition: border-color .18s ease, transform .18s ease, box-shadow .18s ease; }
.subject-card:hover, .module-card:hover { border-color: #aebdaf; transform: translateY(-2px); box-shadow: 0 8px 24px rgba(32,37,34,.045); }
.card-number, .module-index { font-size: .74rem; color: var(--accent); font-weight: 750; letter-spacing: .1em; margin-bottom: 18px; }
.subject-card h3 { font-size: 1.28rem; line-height: 1.3; letter-spacing: -.03em; margin-bottom: 9px; }
.subject-card p, .module-card p { color: var(--muted); font-size: .92rem; margin-bottom: 20px; }
.card-link { margin-top: auto; color: var(--accent-dark); font-weight: 650; font-size: .85rem; }
.title-divider { color: #9aa59b; font-weight: 400; }
.content-main { min-height: 70vh; padding-top: 38px; padding-bottom: 90px; }
.back-link { color: var(--muted); font-size: .86rem; text-decoration: none; display: inline-block; margin-bottom: 42px; }
.back-link:hover { color: var(--accent-dark); }
.content-main h1 { font-size: clamp(2.5rem, 5vw, 4rem); max-width: 900px; }
.page-lead { max-width: 760px; color: #566159; font-size: 1.12rem; line-height: 1.8; margin-bottom: 42px; }
.module-grid { margin-top: 36px; }
.module-card { min-height: 215px; padding: 24px 26px; }
.module-card h2 { font-size: 1.2rem; letter-spacing: -.03em; margin-bottom: 9px; }
.module-card p { margin-bottom: 22px; }
.empty-state { border: 1px dashed #cbd5cb; background: var(--surface); border-radius: 12px; padding: 32px; max-width: 780px; }
.empty-state h2 { font-size: 1.3rem; letter-spacing: -.03em; margin-bottom: 8px; }
.empty-state p { color: var(--muted); margin-bottom: 0; }
.site-footer { max-width: var(--max-width); margin: 0 auto; padding: 22px 28px 30px; border-top: 1px solid var(--line); display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; color: var(--muted); font-size: .8rem; }
.site-footer a { text-decoration: none; }
@media (max-width: 850px) {
  .site-header { align-items: flex-start; flex-direction: column; gap: 16px; }
  .main-nav { justify-content: flex-start; gap: 10px 17px; }
  .intro { padding: 66px 0 60px; }
}
@media (max-width: 600px) {
  .site-header { padding: 20px; }
  .home-main, .content-main { padding-left: 20px; padding-right: 20px; }
  .subject-grid, .module-grid { grid-template-columns: 1fr; }
  .subject-card, .module-card { min-height: 0; padding: 23px; }
  .intro { padding: 54px 0 50px; }
  .explore { padding: 42px 0 64px; }
  .site-footer { padding-left: 20px; padding-right: 20px; }
}