:root {
  color-scheme: dark;
  --bg: #090b10;
  --surface: #111722;
  --surface-2: #151d2a;
  --line: #293448;
  --text: #f5f7fb;
  --muted: #aab4c6;
  --blue: #67a8ff;
  --mint: #68dfbb;
  --amber: #f1be5b;
  --coral: #ff7a70;
  --max: 1180px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 17px/1.65 Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  letter-spacing: 0;
}
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background-image: linear-gradient(rgba(103,168,255,.035) 1px, transparent 1px), linear-gradient(90deg, rgba(104,223,187,.03) 1px, transparent 1px);
  background-size: 58px 58px;
  mask-image: linear-gradient(to bottom, #000, transparent 74%);
}
a { color: inherit; text-decoration-thickness: .08em; text-underline-offset: .18em; }
img { max-width: 100%; }
.skip-link { position: fixed; left: 12px; top: -60px; z-index: 10; padding: 10px 14px; background: var(--text); color: var(--bg); }
.skip-link:focus { top: 12px; }
.site-header {
  min-height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 12px max(24px, calc((100vw - var(--max)) / 2));
  border-bottom: 1px solid var(--line);
  background: rgba(9,11,16,.94);
  position: sticky;
  top: 0;
  z-index: 5;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 800; text-decoration: none; }
.brand img { width: 22px; height: 22px; }
.brand small { padding-left: 10px; border-left: 1px solid var(--line); color: var(--muted); font-weight: 600; }
.site-header nav { display: flex; align-items: center; gap: 24px; color: var(--muted); font-size: 14px; font-weight: 700; }
.site-header nav a:hover, .context-trigger:hover { color: var(--text); }
.context-trigger {
  appearance: none;
  padding: 0;
  border: 0;
  background: transparent;
  color: inherit;
  font: inherit;
  cursor: pointer;
}
.context-trigger.active { color: var(--mint); }
main > section, .article-page, .chapter-page { width: min(var(--max), calc(100% - 48px)); margin-inline: auto; }
.hero {
  min-height: 650px;
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(240px, .65fr);
  gap: 72px;
  align-items: center;
  padding-block: 80px;
}
.hero h1, .article-hero h1 {
  margin: 10px 0 24px;
  font-size: clamp(56px, 8vw, 112px);
  line-height: .92;
  letter-spacing: 0;
}
.hero h1 span { color: var(--mint); }
.hero .dek, .article-hero .dek { max-width: 780px; color: #c9d1de; font-size: clamp(20px, 2.2vw, 28px); line-height: 1.45; }
.hero > img { justify-self: center; width: min(330px, 100%); height: auto; object-fit: cover; border: 1px solid #3b4e69; box-shadow: 0 28px 70px rgba(0,0,0,.42); }
.eyebrow { margin: 0; color: var(--blue); font: 800 12px/1.4 ui-monospace, SFMono-Regular, Menlo, monospace; text-transform: uppercase; letter-spacing: .08em; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin-top: 34px; }
.button { min-height: 48px; display: inline-flex; align-items: center; justify-content: center; padding: 0 18px; border: 1px solid var(--line); border-radius: 5px; font-weight: 800; text-decoration: none; }
.button.primary { background: var(--amber); border-color: var(--amber); color: #17130a; }
.signals { display: grid; grid-template-columns: repeat(4, 1fr); border: 1px solid var(--line); }
.signals div { min-height: 112px; display: grid; place-content: center; padding: 20px; border-right: 1px solid var(--line); text-align: center; }
.signals div:last-child { border-right: 0; }
.signals strong { color: var(--mint); font-size: 34px; line-height: 1; }
.signals span { margin-top: 8px; color: var(--muted); font-size: 13px; }
.intro { max-width: 900px; padding-block: 110px; }
.intro h2, section > .section-head h2, .buy-band h2, .chapter-sections h2 { margin: 10px 0 22px; font-size: clamp(36px, 5vw, 66px); line-height: 1.05; }
.intro > p:last-child { color: var(--muted); font-size: 22px; }
#chapters, #directory { padding-block: 82px; }
.section-head { display: flex; align-items: end; justify-content: space-between; gap: 32px; margin-bottom: 40px; }
.search { min-width: min(420px, 100%); color: var(--muted); font-size: 13px; font-weight: 700; }
.search span { display: block; margin-bottom: 7px; }
.search input { width: 100%; min-height: 48px; padding: 0 14px; border: 1px solid var(--line); border-radius: 4px; background: #0c1119; color: var(--text); font: inherit; }
.chapter-grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 14px; }
.chapter-card { min-height: 260px; padding: 24px; border: 1px solid var(--line); background: var(--surface); }
.chapter-card > span, .chapter-card small { color: var(--blue); font: 750 12px/1.4 ui-monospace, SFMono-Regular, Menlo, monospace; }
.chapter-card h2 { margin: 34px 0 14px; font-size: 24px; line-height: 1.15; }
.chapter-card p { color: var(--muted); font-size: 15px; }
.section-directory { margin: 0; padding: 0; list-style: none; border-top: 1px solid var(--line); }
.section-row a { display: grid; grid-template-columns: 64px 1fr auto; gap: 18px; align-items: center; min-height: 62px; padding: 12px 8px; border-bottom: 1px solid var(--line); text-decoration: none; }
.section-row a:hover { background: var(--surface); }
.section-row span { color: var(--blue); font: 700 12px/1.4 ui-monospace, SFMono-Regular, Menlo, monospace; }
.section-row small { color: var(--muted); }
.buy-band { display: flex; justify-content: space-between; align-items: center; gap: 42px; margin-block: 100px; padding: 54px; border: 1px solid #6e5731; background: #17140e; }
.buy-band h2 { max-width: 800px; font-size: clamp(30px, 4vw, 52px); }
.breadcrumbs { display: flex; flex-wrap: wrap; gap: 9px; padding-top: 36px; color: var(--muted); font-size: 13px; }
.article-hero { padding: 78px 0 58px; border-bottom: 1px solid var(--line); }
.article-hero h1 { max-width: 1000px; font-size: clamp(46px, 7vw, 88px); }
.topic-list { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 24px; }
.topic-list span { padding: 6px 9px; border: 1px solid var(--line); color: var(--muted); font-size: 12px; }
.article-grid, .chapter-summary { display: grid; grid-template-columns: minmax(0, 1.5fr) minmax(280px, .75fr); gap: 64px; padding-block: 64px; }
.guidance h2, .chapter-summary h2 { margin: 0 0 18px; font-size: 30px; }
.guidance h2:not(:first-child) { margin-top: 54px; }
.guidance li, .chapter-summary li { margin-bottom: 14px; padding-left: 8px; color: #d7dde7; }
.expert-note { margin-top: 54px; padding: 28px; border-left: 4px solid var(--mint); background: var(--surface); }
.expert-note p:last-child { margin-bottom: 0; color: #d8dee8; }
.citation-card { align-self: start; position: sticky; top: 96px; display: grid; grid-template-columns: 112px 1fr; gap: 20px; padding: 22px; border: 1px solid var(--line); background: var(--surface); }
.citation-card img { width: 112px; height: 168px; object-fit: cover; }
.citation-card h2 { margin: 8px 0; font-size: 22px; }
.citation-card p { color: var(--muted); font-size: 14px; }
.citation-card .button { width: 100%; margin-top: 12px; }
.cite-this { margin: 30px 0 70px; padding: 26px; border: 1px solid var(--line); background: #0d121a; }
.cite-this code { display: block; margin-top: 12px; color: var(--mint); white-space: normal; overflow-wrap: anywhere; }
.chapter-summary aside { padding: 28px; border: 1px solid var(--line); background: var(--surface); }
.chapter-summary aside p { color: var(--muted); font-size: 14px; }
.artifact-list { color: var(--mint); }
.chatgpt-panel {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 48px;
  align-items: center;
  margin: 18px 0 72px;
  padding: 34px;
  border: 1px solid #6e5731;
  background: #17140e;
}
.chatgpt-panel h2 { margin: 8px 0 10px; font-size: clamp(28px, 4vw, 44px); line-height: 1.05; }
.chatgpt-panel p:last-child { max-width: 720px; margin-bottom: 0; color: var(--muted); }
.chatgpt-actions { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 10px; }
.context-dialog {
  width: min(680px, calc(100% - 30px));
  max-height: calc(100vh - 40px);
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 6px;
  background: var(--surface);
  color: var(--text);
  box-shadow: 0 30px 100px rgba(0,0,0,.72);
}
.context-dialog::backdrop { background: rgba(2,4,8,.78); backdrop-filter: blur(4px); }
.context-dialog form { padding: 30px; }
.context-dialog header { display: flex; align-items: center; justify-content: space-between; gap: 20px; }
.context-dialog h2 { margin: 24px 0 12px; font-size: clamp(30px, 6vw, 48px); line-height: 1; }
.context-dialog > form > p { color: var(--muted); line-height: 1.55; }
.context-dialog label { display: block; margin: 28px 0 8px; font-size: 14px; font-weight: 800; }
.context-dialog textarea {
  width: 100%;
  min-height: 190px;
  resize: vertical;
  padding: 14px;
  border: 1px solid var(--line);
  border-radius: 4px;
  background: #090d14;
  color: var(--text);
  font: inherit;
  font-size: 16px;
  line-height: 1.5;
}
.context-dialog textarea:focus { border-color: var(--blue); outline: 2px solid rgba(103,168,255,.25); outline-offset: 1px; }
.dialog-close {
  width: 38px;
  height: 38px;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: transparent;
  color: var(--muted);
  font-size: 24px;
  line-height: 1;
  cursor: pointer;
}
.context-meta { display: flex; justify-content: space-between; gap: 20px; margin-top: 8px; color: var(--muted); font-size: 12px; }
.dialog-actions { display: flex; justify-content: flex-end; gap: 10px; margin-top: 24px; }
.chapter-sections { padding-block: 40px 80px; }
.chapter-sections ol { margin: 32px 0 0; padding: 0; list-style: none; border-top: 1px solid var(--line); }
.chapter-sections a { min-height: 78px; display: grid; grid-template-columns: 60px 1fr; gap: 16px; align-items: center; padding: 12px 0; border-bottom: 1px solid var(--line); text-decoration: none; }
.chapter-sections a > span { color: var(--blue); font: 700 12px/1.4 ui-monospace, SFMono-Regular, Menlo, monospace; }
.chapter-sections a small { display: block; margin-top: 4px; color: var(--muted); font-weight: 400; }
.pager { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; padding: 28px 0 90px; border-top: 1px solid var(--line); }
.pager a:last-child { text-align: right; }
footer { display: flex; justify-content: space-between; gap: 30px; padding: 34px max(24px, calc((100vw - var(--max)) / 2)); border-top: 1px solid var(--line); color: var(--muted); font-size: 13px; }
.hidden { display: none !important; }
.empty-state { padding: 30px; border: 1px solid var(--line); color: var(--muted); text-align: center; }
@media (max-width: 900px) {
  .hero { min-height: 0; grid-template-columns: 1fr; gap: 44px; padding-block: 58px; }
  .hero > img { width: 250px; justify-self: start; }
  .chapter-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .article-grid, .chapter-summary { grid-template-columns: 1fr; gap: 34px; }
  .citation-card { position: static; }
  .chatgpt-panel { grid-template-columns: 1fr; gap: 24px; }
  .chatgpt-actions { justify-content: flex-start; }
  .section-head { align-items: stretch; flex-direction: column; }
}
@media (max-width: 620px) {
  body { font-size: 16px; }
  main > section, .article-page, .chapter-page { width: min(100% - 30px, var(--max)); }
  .site-header { padding-inline: 15px; }
  .brand small { display: none; }
  .site-header nav a:first-child { display: none; }
  .hero h1 { font-size: 56px; }
  .signals { grid-template-columns: 1fr 1fr; }
  .signals div:nth-child(2) { border-right: 0; }
  .signals div:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
  .chapter-grid { grid-template-columns: 1fr; }
  .chapter-card { min-height: 210px; }
  .section-row a { grid-template-columns: 50px 1fr; }
  .section-row small { display: none; }
  .buy-band { align-items: stretch; flex-direction: column; margin-block: 60px; padding: 28px; }
  .citation-card { grid-template-columns: 84px 1fr; padding: 16px; }
  .citation-card img { width: 84px; height: 126px; }
  .site-header nav { gap: 14px; }
  .chatgpt-panel { margin-bottom: 52px; padding: 24px; }
  .chatgpt-actions { align-items: stretch; flex-direction: column; }
  .context-dialog form { padding: 22px; }
  .dialog-actions .button { flex: 1; }
  footer { flex-direction: column; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }