:root {
  --bg: #07111f;
  --ink: #172033;
  --muted: #607086;
  --line: #dfe7ef;
  --paper: #f7f9fc;
  --white: #fff;
  --cyan: #0bc5db;
  --blue: #3979ff;
  --violet: #7557ff;
  --coral: #ef6b5b;
  --green: #25a775;
  --radius: 22px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }
.skip-link { position: absolute; left: -9999px; top: 8px; z-index: 99; background: #fff; padding: 10px 14px; border-radius: 8px; }
.skip-link:focus { left: 8px; }

.site-header {
  height: 74px;
  padding: 0 clamp(22px, 5vw, 72px);
  display: flex;
  align-items: center;
  justify-content: space-between;
  color: #e9f2ff;
  background: rgba(7, 17, 31, .94);
  border-bottom: 1px solid rgba(255, 255, 255, .1);
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(16px);
}
.brand { display: inline-flex; align-items: center; gap: 12px; font-weight: 750; letter-spacing: .02em; }
.brand-mark {
  width: 34px;
  height: 34px;
  border: 1px solid rgba(255,255,255,.4);
  border-radius: 10px;
  display: grid;
  place-items: center;
  font: 800 15px/1 Georgia, serif;
  color: #fff;
  background: linear-gradient(135deg, #1ab9d5, #7656ff);
  box-shadow: 0 8px 22px rgba(49, 124, 255, .25);
}
.site-nav { display: flex; align-items: center; gap: 30px; font-size: 14px; color: #afbdd0; }
.site-nav > a:not(.admin-link):hover { color: #fff; }
.admin-link {
  padding: 10px 15px;
  color: #fff;
  border: 1px solid rgba(255,255,255,.24);
  border-radius: 11px;
  background: rgba(255,255,255,.08);
  transition: .2s ease;
}
.admin-link:hover { transform: translateY(-1px); background: #fff; color: var(--bg); }

.hero-shell {
  min-height: 650px;
  padding: 68px clamp(22px, 5vw, 72px) 78px;
  display: grid;
  grid-template-columns: minmax(0, .92fr) minmax(440px, 1.08fr);
  gap: clamp(42px, 4vw, 64px);
  align-items: center;
  color: #f7fbff;
  background:
    radial-gradient(circle at 18% 28%, rgba(52, 105, 255, .2), transparent 32%),
    radial-gradient(circle at 88% 10%, rgba(0, 210, 214, .13), transparent 28%),
    var(--bg);
  overflow: hidden;
}
.hero-copy { position: relative; z-index: 1; }
.eyebrow { display: flex; align-items: center; gap: 10px; margin: 0 0 24px; font-size: 12px; font-weight: 750; letter-spacing: .14em; color: #9eb0c8; }
.eyebrow span { width: 28px; height: 2px; background: var(--cyan); }
.hero-copy h1 { margin: 0; font-size: clamp(48px, 4.5vw, 72px); line-height: 1.06; letter-spacing: -.055em; }
.hero-copy h1 em { font-style: normal; color: transparent; background: linear-gradient(90deg, #78e9f1, #8b71ff 70%); -webkit-background-clip: text; background-clip: text; }
.hero-lead { max-width: 670px; margin: 28px 0; font-size: clamp(17px, 1.5vw, 20px); line-height: 1.9; color: #bac8d9; }
.hero-meta { display: flex; gap: 22px; flex-wrap: wrap; color: #7f91a9; font-size: 13px; }
.hero-meta span + span::before { content: "·"; margin-right: 22px; color: #476078; }
.hero-visual { margin: 0; position: relative; }
.hero-visual::before {
  content: "";
  position: absolute;
  inset: -24px;
  border-radius: 36px;
  background: linear-gradient(135deg, rgba(52, 218, 235, .16), rgba(118, 86, 255, .05));
  filter: blur(12px);
}
.hero-visual img { position: relative; width: 100%; border-radius: 26px; border: 1px solid rgba(255,255,255,.17); box-shadow: 0 34px 80px rgba(0,0,0,.42); }
.hero-visual figcaption { position: relative; margin: 13px 5px 0; text-align: right; font-size: 12px; color: #71849b; }

.quick-answer {
  max-width: 1280px;
  margin: -36px auto 70px;
  padding: 18px;
  display: grid;
  grid-template-columns: 190px 1fr;
  align-items: stretch;
  position: relative;
  z-index: 2;
  background: #fff;
  border: 1px solid #e2e9f0;
  border-radius: 20px;
  box-shadow: 0 20px 48px rgba(29, 48, 75, .12);
}
.quick-title { display: flex; flex-direction: column; justify-content: center; padding: 12px 20px; border-right: 1px solid var(--line); }
.quick-title span { width: max-content; padding: 4px 7px; border-radius: 5px; color: #fff; background: var(--bg); font-size: 10px; font-weight: 800; letter-spacing: .08em; }
.quick-title h2 { margin: 9px 0 0; font-size: 19px; }
.quick-grid { display: grid; grid-template-columns: repeat(5, 1fr); }
.quick-card { padding: 14px 17px; border-left: 1px solid #eef2f6; transition: .2s ease; }
.quick-card:hover { transform: translateY(-2px); background: #f8fbff; border-radius: 10px; }
.quick-card strong, .quick-card span { display: block; }
.quick-card strong { font-size: 12px; color: var(--muted); font-weight: 600; }
.quick-card span { margin-top: 7px; font-size: 14px; font-weight: 760; }
.quick-card.cyan span { color: #018c9c; }
.quick-card.coral span { color: #d45244; }
.quick-card.violet span { color: #6546df; }
.quick-card.blue span { color: #2f6add; }
.quick-card.green span { color: #16865c; }

.reading-layout { max-width: 1140px; margin: 0 auto; padding: 0 24px 120px; display: grid; grid-template-columns: 170px minmax(0, 820px); gap: 70px; align-items: start; }
.article { min-width: 0; }
.toc { position: sticky; top: 110px; display: flex; flex-direction: column; gap: 12px; padding-left: 17px; border-left: 1px solid #d6e0e9; font-size: 13px; }
.toc p { margin: 0 0 3px; font-size: 11px; font-weight: 800; color: #94a0af; letter-spacing: .08em; }
.toc a { color: #718095; }
.toc a:hover { color: #2e6ce7; }
.article section { scroll-margin-top: 105px; margin-bottom: 96px; }
.section-kicker { margin: 0 0 14px; color: #2d6fe8; font-size: 12px; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; }
.article h2 { margin: 0 0 24px; font-size: clamp(30px, 4vw, 45px); line-height: 1.25; letter-spacing: -.035em; }
.article h3 { letter-spacing: -.015em; }
.article > section > p:not(.section-kicker):not(.fine-print), .model-card p { font-size: 17px; line-height: 1.9; color: #445269; }
.lead-paragraph { font-size: 20px !important; line-height: 1.85 !important; color: #243249 !important; }
.callout { margin-top: 30px; padding: 24px 26px; display: grid; grid-template-columns: 38px 1fr; gap: 16px; border: 1px solid #cfe2ff; border-radius: 16px; background: #edf5ff; }
.callout p { margin: 0; color: #29486d; line-height: 1.8; }
.callout-icon { width: 36px; height: 36px; display: grid; place-items: center; border-radius: 10px; color: #fff; background: #3479ef; font-size: 21px; }

.table-wrap { width: 100%; max-width: 100%; margin-top: 30px; overflow-x: auto; border: 1px solid var(--line); border-radius: 16px; background: #fff; box-shadow: 0 12px 32px rgba(38, 59, 82, .06); }
table { width: 100%; min-width: 760px; border-collapse: collapse; }
th, td { padding: 17px 18px; text-align: left; border-bottom: 1px solid #e8edf2; font-size: 14px; vertical-align: middle; }
th { color: #6d7a8d; background: #f4f7fa; font-size: 12px; letter-spacing: .03em; }
tbody tr:last-child td { border-bottom: 0; }
tbody tr:hover td { background: #fbfdff; }
.tag { display: inline-flex; padding: 5px 9px; border-radius: 999px; font-size: 11px; font-weight: 750; white-space: nowrap; }
.tag.open { color: #0a7e54; background: #e4f8ef; }
.tag.closed { color: #53637a; background: #edf1f5; }
.fine-print { color: #8390a1; font-size: 12px; line-height: 1.7; }

.model-card { margin-top: 20px; padding: 30px; display: grid; grid-template-columns: 52px 1fr; gap: 20px; border: 1px solid var(--line); border-radius: var(--radius); background: #fff; box-shadow: 0 12px 36px rgba(36, 55, 77, .055); scroll-margin-top: 104px; }
.model-index { padding-top: 5px; font: 700 12px/1 ui-monospace, SFMono-Regular, Menlo, monospace; color: #9aa6b5; }
.model-heading { display: flex; align-items: center; gap: 11px; flex-wrap: wrap; }
.model-heading h3 { margin: 0; font-size: 25px; }
.model-dot { width: 10px; height: 10px; border-radius: 50%; box-shadow: 0 0 0 5px color-mix(in srgb, currentColor 13%, transparent); }
.model-label { margin-left: auto; padding: 5px 9px; border-radius: 7px; background: #f1f4f8; color: #617087; font-size: 11px; font-weight: 700; }
.model-card p { margin: 18px 0; }
.model-card ul { margin: 0; padding: 0; list-style: none; }
.model-card li { padding: 8px 0 8px 20px; position: relative; color: #55647a; font-size: 14px; line-height: 1.75; }
.model-card li::before { content: ""; width: 6px; height: 6px; border-radius: 50%; position: absolute; left: 1px; top: 17px; background: currentColor; opacity: .45; }
.blue-model .model-dot { color: var(--blue); background: var(--blue); }
.cyan-model .model-dot { color: var(--cyan); background: var(--cyan); }
.coral-model .model-dot { color: var(--coral); background: var(--coral); }
.violet-model .model-dot { color: var(--violet); background: var(--violet); }
.green-model .model-dot { color: var(--green); background: var(--green); }

.decision-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 15px; }
.decision-card { padding: 25px; border: 1px solid var(--line); border-radius: 18px; background: #fff; }
.decision-no { width: 32px; height: 32px; display: grid; place-items: center; border-radius: 9px; background: #eaf2ff; color: #2f70df; font: 800 12px/1 ui-monospace, monospace; }
.decision-card h3 { margin: 18px 0 10px; font-size: 18px; }
.decision-card p { margin: 0; color: #657388; font-size: 14px; line-height: 1.75; }
.method-box { margin-top: 22px; padding: 30px; color: #e9f2ff; border-radius: 20px; background: var(--bg); box-shadow: 0 22px 50px rgba(10, 23, 42, .18); }
.method-box h3 { margin: 0 0 18px; font-size: 22px; }
.method-box ol { margin: 0; padding: 0; list-style: none; counter-reset: steps; display: grid; gap: 14px; }
.method-box li { counter-increment: steps; display: grid; grid-template-columns: 30px 1fr; gap: 10px; align-items: start; color: #b5c3d5; line-height: 1.7; font-size: 14px; }
.method-box li::before { content: counter(steps); width: 25px; height: 25px; display: grid; place-items: center; border: 1px solid #43617f; border-radius: 50%; color: #70dce5; font-size: 11px; font-weight: 800; }

blockquote { margin: 32px 0; padding: 8px 0 8px 28px; border-left: 4px solid var(--violet); }
blockquote p { margin: 0; font: 600 24px/1.65 Georgia, "Songti SC", serif; color: #252b40; }
.sources { padding-top: 4px; }
.source-list { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; margin: 25px 0; }
.source-list a { padding: 16px 18px; display: grid; grid-template-columns: 1fr auto; align-items: center; gap: 5px 10px; border: 1px solid var(--line); border-radius: 13px; background: #fff; font-size: 14px; font-weight: 700; transition: .2s ease; }
.source-list a:hover { transform: translateY(-2px); border-color: #a9c8ff; box-shadow: 0 10px 26px rgba(46, 103, 199, .09); }
.source-list span { grid-column: 1 / -1; color: #8a96a6; font-size: 10px; font-weight: 700; text-transform: uppercase; letter-spacing: .09em; }
.source-list b { color: #6a80a0; }

footer { padding: 48px clamp(24px, 5vw, 72px); display: flex; align-items: flex-end; justify-content: space-between; gap: 30px; color: #a9b8ca; background: var(--bg); border-top: 1px solid rgba(255,255,255,.1); }
.footer-brand { color: #fff; }
footer p { margin: 16px 0 0; color: #71849b; font-size: 13px; }
.footer-right { display: flex; gap: 24px; color: #71849b; font-size: 13px; }
.footer-right a:hover { color: #fff; }

@media (max-width: 1100px) {
  .hero-shell { grid-template-columns: 1fr; }
  .hero-copy { max-width: 800px; }
  .hero-visual { max-width: 900px; }
  .quick-answer { margin-left: 22px; margin-right: 22px; grid-template-columns: 1fr; }
  .quick-title { border-right: 0; border-bottom: 1px solid var(--line); }
  .reading-layout { grid-template-columns: minmax(0, 1fr); max-width: 870px; }
  .toc { display: none; }
}

@media (max-width: 780px) {
  .site-header { height: auto; min-height: 68px; padding: 14px 18px; }
  .site-nav > a:not(.admin-link) { display: none; }
  .site-nav { gap: 0; }
  .admin-link { padding: 9px 12px; font-size: 13px; }
  .hero-shell { min-height: 0; padding: 56px 20px 78px; gap: 38px; }
  .hero-copy h1 { font-size: clamp(43px, 13vw, 63px); }
  .hero-lead { font-size: 16px; }
  .hero-meta { gap: 8px 14px; }
  .hero-meta span + span::before { margin-right: 14px; }
  .hero-visual img { border-radius: 18px; }
  .quick-answer { margin: -30px 14px 62px; padding: 12px; }
  .quick-grid { grid-template-columns: repeat(2, 1fr); }
  .quick-card { border-bottom: 1px solid #eef2f6; }
  .quick-card:last-child { grid-column: 1 / -1; }
  .reading-layout { padding: 0 18px 80px; }
  .article section { margin-bottom: 72px; }
  .article h2 { font-size: 32px; }
  .lead-paragraph { font-size: 18px !important; }
  .callout { grid-template-columns: 1fr; }
  .model-card { grid-template-columns: 1fr; padding: 23px; }
  .model-index { display: none; }
  .model-label { margin-left: 0; }
  .decision-grid, .source-list { grid-template-columns: 1fr; }
  blockquote p { font-size: 21px; }
  footer { align-items: flex-start; flex-direction: column; }
  .footer-right { width: 100%; justify-content: space-between; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; }
}