:root {
  --bg: #fbfaf7;
  --surface: #ffffff;
  --text: #1c1b19;
  --muted: #66625b;
  --line: #e6e2da;
  --ink: #1c1b19;
  --on-ink: #ffffff;
  --radius: 14px;
  --accent-lift: 0%;
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #121214;
    --surface: #1a1a1d;
    --text: #ecebe8;
    --muted: #a39f97;
    --line: #2c2c31;
    --ink: #ecebe8;
    --on-ink: #121214;
    --accent-lift: 40%; /* mixes some text colour into accent-coloured text so it stays readable */
    color-scheme: dark;
  }
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
body { margin: 0; background: var(--bg); color: var(--text); font: 17px/1.6 Inter, system-ui, -apple-system, "Segoe UI", sans-serif; }
a { color: inherit; }
h1, h2, h3 { line-height: 1.15; letter-spacing: -0.02em; margin: 0; overflow-wrap: break-word; }
main { max-width: 1080px; margin: 0 auto; padding: 0 24px; }
section { margin: 72px 0; }
:focus-visible { outline: 3px solid var(--ink); outline-offset: 2px; }
.sr-only { position: absolute; width: 1px; height: 1px; margin: -1px; padding: 0; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0; }
.skip { position: absolute; top: -64px; left: 16px; z-index: 10; padding: 8px 16px; border-radius: 10px; background: var(--ink); color: var(--on-ink); font-weight: 600; text-decoration: none; }
.skip:focus { top: 12px; }

/* Elements that carry a guide's --accent also get a text-safe version of it. */
.path, .guide, .guide-row, .lesson-group { --accent-text: color-mix(in srgb, var(--accent), var(--text) var(--accent-lift)); }

.top { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 8px 16px; padding: 14px 24px; border-bottom: 1px solid var(--line); }
.brand { font-weight: 700; text-decoration: none; white-space: nowrap; }
.brand span { color: var(--muted); font-weight: 500; }
.top nav { display: flex; gap: 18px; font-size: 15px; align-items: center; }
.top nav a { color: var(--muted); text-decoration: none; white-space: nowrap; }
.top nav a:hover, .top nav a[aria-current="page"] { color: var(--text); }
.top nav .follow { color: var(--text); font-weight: 600; }

.btn { display: inline-block; padding: 10px 18px; border-radius: 999px; border: 1px solid var(--line); background: var(--surface); color: inherit; text-decoration: none; font: inherit; font-weight: 600; font-size: 15px; cursor: pointer; }
.btn.primary { background: var(--ink); border-color: var(--ink); color: var(--on-ink); }
.btn:hover { filter: brightness(1.06); }

.hero { margin-top: 80px; }
.eyebrow { color: var(--muted); font-weight: 600; font-size: 14px; text-transform: uppercase; letter-spacing: 0.06em; margin: 0 0 10px; }
.hero h1 { font-size: clamp(44px, 8vw, 84px); font-weight: 800; }
.pitch { font-size: clamp(19px, 2.4vw, 23px); color: var(--muted); max-width: 680px; margin: 18px 0 10px; }
.count { font-size: 15px; color: var(--muted); margin: 0; }
.actions { display: flex; flex-wrap: wrap; gap: 10px; margin: 28px 0 0; }

/* Section headings and the small cards ("Start here", "Latest", "More series") */
.start h2, .latest h2, .series-head h2, .more-series h2 { font-size: 26px; }
.series-head { display: flex; align-items: baseline; gap: 6px 14px; flex-wrap: wrap; margin-bottom: 18px; }
.series-head p { margin: 0; color: var(--muted); }
.paths { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 14px; margin-top: 18px; }
.path {
  display: flex; flex-direction: column; gap: 4px; padding: 20px; text-decoration: none;
  background: var(--surface); border: 1px solid var(--line); border-top: 4px solid var(--accent); border-radius: var(--radius);
  transition: transform 0.15s, box-shadow 0.15s;
}
.path:hover { transform: translateY(-2px); box-shadow: 0 10px 30px -18px rgb(0 0 0 / 0.4); }
.path .if { font-weight: 700; font-size: 18px; }
.path .then { color: var(--muted); }
.path .go { margin-top: auto; padding-top: 10px; font-weight: 600; color: var(--accent-text); }

/* Home: one card per series, with a compact row per guide */
.series-cards { display: grid; gap: 16px; }
.series-card {
  display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.6fr); grid-template-areas: "head rows" "more rows"; gap: 12px 36px; padding: 26px;
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
}
.series-card-head { grid-area: head; }
.series-card h3 { font-size: 24px; margin-bottom: 8px; }
.series-card h3 a { text-decoration: none; }
.series-card h3 a:hover { text-decoration: underline; }
.series-card-head p { margin: 0; color: var(--muted); }
.series-card-head .count { margin-top: 10px; font-size: 14px; }
.series-card .more { grid-area: more; align-self: end; font-weight: 600; font-size: 15px; text-decoration: none; }
.series-card .more:hover { text-decoration: underline; }
.guide-rows { grid-area: rows; list-style: none; margin: 0; padding: 0; display: grid; gap: 14px; align-content: start; }
.guide-row { padding: 2px 0 2px 16px; border-left: 3px solid var(--accent); }
.guide-row-top { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: baseline; gap: 2px 16px; }
.guide-row-top a { font-weight: 700; font-size: 18px; text-decoration: none; }
.guide-row-top a:hover { text-decoration: underline; text-decoration-color: var(--accent); }
.guide-row-top span { font-size: 13px; color: var(--muted); white-space: nowrap; }
.guide-row p { margin: 2px 0 0; color: var(--muted); font-size: 15px; display: -webkit-box; -webkit-box-orient: vertical; -webkit-line-clamp: 1; line-clamp: 1; overflow: hidden; }

/* Series page */
.crumbs { margin-top: 28px; font-size: 14px; color: var(--muted); }
.crumbs ol { list-style: none; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 4px 8px; }
.crumbs li + li::before { content: "›"; margin-right: 8px; }
.crumbs a { color: var(--muted); }
.crumbs a:hover { color: var(--text); }
.crumbs [aria-current] { color: var(--text); font-weight: 600; }
.crumbs + .hero { margin-top: 40px; }
.guides { display: grid; gap: 16px; }
.guide {
  display: grid; grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr); gap: 8px 32px; padding: 26px;
  background: var(--surface); border: 1px solid var(--line); border-left: 5px solid var(--accent); border-radius: var(--radius);
}
.guide-head { grid-column: 1; }
.format { font-size: 13px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.05em; color: var(--accent-text); }
.guide h2 { font-size: 28px; margin: 6px 0 8px; }
.guide h2 a { text-decoration: none; }
.guide h2 a:hover { text-decoration: underline; text-decoration-color: var(--accent); }
.part { color: var(--muted); font-weight: 600; }
.guide-head p { margin: 0; color: var(--muted); }
.facts { grid-column: 1; list-style: none; padding: 0; margin: 12px 0 0; display: flex; flex-wrap: wrap; gap: 8px; }
.facts li { font-size: 13px; padding: 3px 10px; border-radius: 999px; background: var(--bg); border: 1px solid var(--line); }
.toc { grid-column: 2; grid-row: 1 / span 3; margin: 0; padding-left: 22px; font-size: 15.5px; }
.toc li { padding: 3px 0; }
.toc li::marker { color: var(--accent-text); font-weight: 700; }
.toc a { text-decoration: none; }
.toc a:hover { text-decoration: underline; text-decoration-color: var(--accent); }
.guide-links { grid-column: 1; display: flex; gap: 10px; flex-wrap: wrap; margin-top: 16px; }

/* All lessons */
.filters { display: grid; gap: 12px; margin-bottom: 14px; }
.filter-row { display: flex; flex-wrap: wrap; gap: 10px; }
.search, .select { font: inherit; font-size: 16px; padding: 10px 14px; border-radius: 10px; border: 1px solid var(--line); background: var(--surface); color: var(--text); min-width: 0; max-width: 100%; }
.search { flex: 1 1 260px; max-width: 420px; }
.select { flex: 0 1 auto; cursor: pointer; }
.chips { display: flex; flex-wrap: wrap; gap: 6px; }
.chip { font: inherit; font-size: 14px; padding: 5px 12px; border-radius: 999px; border: 1px solid var(--line); background: var(--surface); color: var(--muted); cursor: pointer; }
.chip:hover { color: var(--text); }
.chip[aria-pressed="true"] { background: var(--ink); border-color: var(--ink); color: var(--on-ink); }
.lesson-groups { display: grid; gap: 32px; margin-top: 22px; }
.lesson-group { margin: 0; }
.group-head { display: flex; flex-wrap: wrap; align-items: baseline; gap: 2px 14px; padding-bottom: 8px; border-bottom: 2px solid var(--accent); }
.group-head h2 { font-size: 21px; }
.group-head h2 a { text-decoration: none; }
.group-head h2 a:hover { text-decoration: underline; text-decoration-color: var(--accent); }
.group-head p { margin: 0; font-size: 14px; color: var(--muted); }
.group-head p a { color: var(--accent-text); font-weight: 600; text-decoration: none; }
.group-head p a:hover { text-decoration: underline; }
.lesson-list { list-style: none; padding: 0; margin: 0; }
.lesson-list li { display: flex; justify-content: space-between; align-items: baseline; gap: 4px 16px; padding: 11px 4px; border-bottom: 1px solid var(--line); }
.lesson-list a { font-weight: 600; text-decoration: none; }
.lesson-list a:hover { text-decoration: underline; text-decoration-color: var(--accent); }
.lesson-topics { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 6px; font-size: 13px; color: var(--muted); }
.lesson-topics span:not(.sr-only) { padding: 1px 8px; border-radius: 999px; border: 1px solid var(--line); white-space: nowrap; }
.empty { color: var(--muted); }
.empty p { margin: 8px 0 12px; }

.about { background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); padding: 32px; }
.about p { color: var(--muted); max-width: 640px; }

.foot { text-align: center; color: var(--muted); font-size: 15px; padding: 28px 24px 48px; border-top: 1px solid var(--line); }
.foot p { margin: 0; }
.foot-nav { display: flex; flex-wrap: wrap; justify-content: center; gap: 6px 22px; margin-bottom: 12px; }
.foot-nav a { text-decoration: none; }
.foot-nav a:hover, .foot-nav a[aria-current="page"] { color: var(--text); text-decoration: underline; }

@media (max-width: 820px) {
  main { padding: 0 16px; }
  section { margin: 48px 0; }
  .hero { margin-top: 48px; }
  .crumbs + .hero { margin-top: 28px; }
  .top { padding: 12px 16px; }
  .top nav .github { display: none; }
  .paths { grid-template-columns: minmax(0, 1fr); }
  .series-card { grid-template-columns: minmax(0, 1fr); grid-template-areas: "head" "rows" "more"; gap: 16px; padding: 20px; }
  .guide-row p { -webkit-line-clamp: 2; line-clamp: 2; }
  .guide { grid-template-columns: minmax(0, 1fr); padding: 20px; }
  .toc, .facts, .guide-links, .guide-head { grid-column: 1; grid-row: auto; }
  .toc { margin-top: 10px; }
  .lesson-list li { flex-direction: column; gap: 4px; }
  .lesson-topics { justify-content: flex-start; }
  .about { padding: 24px 20px; }
  .foot { padding: 24px 16px 40px; }
}
@media (max-width: 520px) {
  .brand span { display: none; }
}