:root {
  color-scheme: dark;
  --bg: #141615;
  --panel: #191c1a;
  --text: #e7eae7;
  --muted: #9da59f;
  --line: #303631;
  --accent: #7bb995;
  --sidebar: 250px;
  font-family: 'DM Sans', sans-serif;
  font-size: 16px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 32px; }
body { margin: 0; background: var(--bg); color: var(--text); -webkit-font-smoothing: antialiased; }
a { color: inherit; text-decoration: none; }
button { font: inherit; }
a, button { -webkit-tap-highlight-color: transparent; }
a:focus-visible, button:focus-visible { outline: 2px solid var(--accent); outline-offset: 5px; }
svg { width: 20px; height: 20px; flex-shrink: 0; }
::selection { background: #345341; color: #fff; }
h1, h2, h3, p { margin: 0; }
.sidebar { position: fixed; inset: 0 auto 0 0; width: var(--sidebar); padding: 33px 22px 0; background: #171a18; border-right: 1px solid var(--line); display: flex; flex-direction: column; overflow: auto; z-index: 30; }
.brand { display: block; width: max-content; font-size: 2.2rem; font-weight: 600; letter-spacing: -1.7px; line-height: 1; }
.brand-period { color: var(--accent); }
.sidebar-caption { color: var(--muted); font-size: .8125rem; margin: 15px 0 35px; }
.overview-link { display: flex; gap: 12px; align-items: center; padding: 12px; font-size: .875rem; border-radius: 5px; }
.overview-link svg { width: 17px; height: 17px; }
/* Reserve green for orientation and interaction rather than decorative surfaces. */
.overview-link.active { color: var(--accent); background: #222824; }
.overview-link:hover { background: #252a26; }
.nav-label { color: #858e87; font-size: .75rem; margin: 28px 12px 20px; }
.nav-group { margin-bottom: 19px; }
.nav-group-title { display: flex; align-items: center; gap: 11px; color: #cbd1cb; font-size: .875rem; padding: 3px 12px 9px; }
.nav-group-title svg { width: 16px; height: 16px; color: #868f88; }
.nav-topics { border-left: 1px solid var(--line); margin-left: 20px; padding-left: 20px; display: flex; flex-direction: column; }
.nav-topics a { font-size: .875rem; color: var(--muted); padding: 8px 0; line-height: 1.4; }
.nav-topics a:hover, .nav-topics a.active, .nav-group-title:hover { color: var(--accent); }
.creator { margin-top: auto; padding: 24px 0 20px; border-top: 1px solid var(--line); font-size: .8125rem; line-height: 1.8; color: #bbc3bc; }
.creator span { display: block; font-size: .75rem; color: var(--muted); }
.sidebar-footer { border-top: 1px solid var(--line); padding: 18px 0; font-size: .75rem; line-height: 1.5; color: #89928b; }
.workspace { margin-left: var(--sidebar); }
.topbar { min-height: 78px; border-bottom: 1px solid var(--line); padding: 18px 45px; display: flex; align-items: center; justify-content: space-between; gap: 18px; font-size: .875rem; }
.breadcrumb { display: flex; align-items: center; gap: 15px; }
.breadcrumb-root { color: var(--muted); }
.slash { color: #626c64; }
.free-label { display: flex; align-items: center; gap: 8px; color: var(--muted); font-size: .8125rem; white-space: nowrap; }
.free-label svg { width: 14px; height: 14px; }
main { max-width: 1270px; margin: 0 auto; padding: 34px 45px 0; outline: none; }
/* A typography-led introduction keeps attention on the curriculum. */
.hero { padding: 22px 0 34px; }
.eyebrow { font-size: .8125rem; font-weight: 400; color: var(--muted); line-height: 1.6; }
.hero h1 { font-size: clamp(2rem, 3.7vw, 3.3rem); font-weight: 450; line-height: 1.16; letter-spacing: -1.8px; margin: 23px 0 23px; }
.hero h1 span { color: #bac4bc; }
.hero p { font-size: 1rem; color: var(--muted); line-height: 1.8; max-width: 630px; }
.hero-link { display: flex; align-items: center; gap: 16px; width: max-content; margin-top: 25px; font-size: .875rem; color: var(--accent); }
.hero-link:hover { text-decoration: underline; text-underline-offset: 5px; }
.proof-strip { display: flex; align-items: center; gap: 18px; padding: 20px 0; border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); font-size: .8125rem; color: var(--muted); line-height: 1.6; }
.proof-strip strong { font-weight: 500; color: #c6cfc7; }
.proof-divider { width: 1px; height: 14px; background: var(--line); }
.no-paywall { margin-left: auto; font-size: .75rem; }
.curriculum { padding-top: 37px; }
.section-heading { display: flex; align-items: flex-end; justify-content: space-between; gap: 20px; margin-bottom: 26px; }
.section-heading h2 { font-size: 1.65rem; font-weight: 450; letter-spacing: -.6px; margin-top: 8px; line-height: 1.3; }
.section-count { font-size: .75rem; color: var(--muted); white-space: nowrap; padding-bottom: 3px; }
.section-count span { margin: 0 8px; color: #657067; }
.cards { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
.guide-card { display: flex; flex-direction: column; background: var(--panel); border: 1px solid var(--line); border-radius: 8px; padding: 27px 28px 20px; }
.card-top { margin-bottom: 18px; }
.card-number { font-size: .8125rem; color: #8d9890; font-variant-numeric: tabular-nums; }
.guide-card h3 { font-size: 1.4rem; font-weight: 500; letter-spacing: -.5px; }
.guide-card h3 a:hover { color: var(--accent); }
.guide-card > p { font-size: 1rem; color: var(--muted); line-height: 1.65; margin: 9px 0 23px; }
.card-lessons { margin-bottom: 23px; }
.card-lessons a { display: flex; align-items: center; justify-content: space-between; gap: 15px; min-height: 45px; border-top: 1px solid var(--line); padding: 11px 0; color: #c3ccc5; font-size: .875rem; line-height: 1.5; }
.card-lessons svg { width: 15px; height: 15px; color: #87938a; }
.card-lessons a:hover, .card-lessons a:hover svg { color: var(--accent); }
.card-bottom { margin-top: auto; display: flex; justify-content: space-between; gap: 12px; padding-top: 16px; border-top: 1px solid var(--line); color: #8f9a92; font-size: .75rem; }
.closing-note { display: flex; align-items: center; gap: 20px; padding: 35px 0; }
.closing-note p { font-size: .9375rem; line-height: 1.8; color: #c0c9c2; }
.closing-note p span { font-size: .875rem; color: var(--muted); }
.closing-wordmark { margin-left: auto; font-size: 2rem; font-weight: 500; letter-spacing: -1px; color: #636e66; }
.page-footer { padding: 23px 45px; border-top: 1px solid var(--line); display: flex; justify-content: space-between; gap: 18px; color: #8b978e; font-size: .75rem; line-height: 1.7; }
.footer-slash { margin: 0 9px; }
.mobile-toggle, .scrim { display: none; }
.lesson { max-width: 780px; margin: 0 auto; padding: 10px 0 40px; }
.back-link { display: inline-block; color: var(--muted); font-size: .875rem; margin-bottom: 42px; }
.back-link:hover { color: var(--accent); }
.lesson-eyebrow { display: flex; justify-content: space-between; gap: 15px; }
.lesson-eyebrow > span { font-size: .75rem; }
.lesson h1 { font-size: clamp(2rem, 3.8vw, 3.2rem); font-weight: 450; letter-spacing: -1.4px; line-height: 1.15; margin: 20px 0 24px; }
.lesson-intro { font-size: 1.125rem; line-height: 1.8; color: #aeb9b0; }
.lesson-rule { height: 1px; background: var(--line); margin: 33px 0; }
.lesson-section-number, .takeaway > span { font-size: .8125rem; color: var(--muted); }
.lesson-body h2 { font-size: 1.65rem; font-weight: 450; letter-spacing: -.5px; line-height: 1.4; margin: 15px 0 22px; }
.lesson-body > p { font-size: 1rem; line-height: 1.9; color: #bbc5be; margin-bottom: 22px; }
.practice { padding: 24px 27px; border: 1px solid var(--line); border-radius: 7px; background: var(--panel); margin: 32px 0; }
.practice .eyebrow { color: #cbd3cd; font-weight: 500; }
.practice p { color: #b0bcb3; font-size: 1rem; line-height: 1.8; margin-top: 12px; }
.takeaway { margin: 31px 0 37px; }
.takeaway p { font-size: 1.2rem; line-height: 1.65; margin-top: 12px; }
.next-lesson { display: flex; align-items: center; justify-content: space-between; gap: 20px; border-top: 1px solid var(--line); padding: 26px 0; }
.next-lesson span { display: block; font-size: .75rem; color: var(--muted); margin-bottom: 9px; }
.next-lesson strong { font-size: 1.125rem; font-weight: 500; }
.next-lesson svg { color: #a4b0a7; }
.next-lesson:hover strong, .next-lesson:hover svg { color: var(--accent); }
@media (max-width: 1100px) {
  :root { --sidebar: 230px; }
  .sidebar { padding-left: 17px; padding-right: 17px; }
  main { padding: 27px 28px 0; }
  .topbar, .page-footer { padding-left: 28px; padding-right: 28px; }
  .proof-strip > span:nth-child(3), .proof-divider { display: none; }
  .guide-card { padding: 24px 23px 20px; }
  .page-footer > span:first-child { display: none; }
}
@media (max-width: 760px) {
  :root { --sidebar: 250px; }
  .sidebar { transform: translateX(-100%); transition: transform .2s; }
  .workspace { margin-left: 0; }
  .mobile-toggle { display: flex; flex-direction: column; justify-content: center; gap: 5px; position: fixed; top: 18px; left: 17px; width: 34px; height: 34px; padding: 8px; background: var(--panel); border: 1px solid var(--line); border-radius: 4px; z-index: 50; }
  .mobile-toggle span { width: 16px; height: 1px; background: #c7d0c9; }
  .topbar { min-height: 70px; padding: 18px 20px 18px 67px; gap: 12px; }
  .breadcrumb { min-width: 0; font-size: .8125rem; }
  .breadcrumb-root, .breadcrumb .slash { display: none; }
  .free-label { font-size: .75rem; }
  .nav-open { overflow: hidden; }
  .nav-open .sidebar { transform: translateX(0); }
  .nav-open .mobile-toggle { left: 203px; }
  .nav-open .scrim { display: block; position: fixed; inset: 0; background: #0009; z-index: 20; }
  .nav-topics a { padding: 10px 0; }
  .creator { margin-top: 20px; }
  main { padding: 24px 23px 0; }
  .hero { padding: 16px 0 30px; }
  .hero h1 { font-size: clamp(1.8rem, 6.2vw, 2.65rem); letter-spacing: -1px; line-height: 1.23; }
  .hero p br { display: none; }
  .proof-strip { flex-wrap: wrap; gap: 7px; }
  .no-paywall { margin-left: auto; }
  .curriculum { padding-top: 29px; }
  .section-count { display: none; }
  .cards { grid-template-columns: 1fr; gap: 16px; }
  .guide-card { padding: 25px; }
  .closing-wordmark { display: none; }
  .page-footer { padding: 20px 23px; }
  .lesson { padding-top: 7px; }
  .lesson h1 { font-size: 2.3rem; }
  .lesson-body h2 { font-size: 1.5rem; }
  .practice { padding: 22px; }
}
@media (max-width: 380px) {
  main { padding-left: 18px; padding-right: 18px; }
  .no-paywall { margin-left: 0; }
  .hero h1 { font-size: 1.8rem; }
}
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}