:root {
  --ink: #172126;
  --muted: #58666c;
  --line: #dce4e5;
  --surface: #ffffff;
  --soft: #f3f7f6;
  --dark: #102a2c;
  --dark-soft: #18383a;
  --teal: #087f79;
  --teal-dark: #05655f;
  --coral: #e45d3f;
  --code: #102126;
  --shadow: 0 16px 42px rgba(16, 42, 44, 0.09);
  --shell: 1120px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--surface);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.75;
}
a { color: var(--teal-dark); text-underline-offset: 3px; }
a:hover { color: var(--coral); }
img { max-width: 100%; height: auto; }
.shell { width: min(calc(100% - 40px), var(--shell)); margin-inline: auto; }
.skip-link { position: fixed; left: 16px; top: -80px; z-index: 100; padding: 10px 14px; color: #fff; background: #000; }
.skip-link:focus { top: 12px; }

.site-header { position: sticky; top: 0; z-index: 20; border-bottom: 1px solid rgba(255,255,255,.08); background: rgba(16,42,44,.96); backdrop-filter: blur(16px); }
.site-header-inner { min-height: 68px; display: flex; align-items: center; gap: 28px; }
.site-brand { display: flex; align-items: center; gap: 10px; color: #fff; text-decoration: none; flex: 0 0 auto; }
.site-brand img { width: 34px; height: 34px; border-radius: 6px; object-fit: cover; }
.site-brand span, .site-brand strong, .site-brand small { display: block; }
.site-brand strong { font-size: 14px; line-height: 1.25; }
.site-brand small { margin-top: 3px; color: #9eb8b7; font-size: 10px; line-height: 1.2; }
.site-nav { display: flex; align-items: center; gap: 22px; margin-left: auto; }
.site-nav a { color: #c7d8d7; font-size: 13px; text-decoration: none; }
.site-nav a:hover { color: #fff; }
.site-nav a[aria-current="page"] { color: #fff; font-weight: 750; box-shadow: inset 0 -2px 0 var(--coral); }
.header-action { min-height: 38px; display: inline-flex; align-items: center; justify-content: center; padding: 0 16px; border: 1px solid #5ca49f; border-radius: 6px; color: #fff; font-size: 13px; font-weight: 700; text-decoration: none; }
.header-action:hover { color: #fff; background: rgba(255,255,255,.08); }

.page-hero { color: #edf7f6; background: var(--dark); border-bottom: 4px solid var(--teal); }
.page-hero-inner { min-height: 280px; display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 54px; align-items: center; padding-block: 58px; }
.page-hero h1 { max-width: 820px; margin: 0; color: #fff; font-size: 44px; line-height: 1.16; letter-spacing: 0; }
.page-hero p { max-width: 820px; margin: 18px 0 0; color: #b9cccb; font-size: 17px; line-height: 1.75; }
.hero-actions { display: flex; flex-direction: column; gap: 10px; min-width: 190px; }
.button { min-height: 44px; display: inline-flex; align-items: center; justify-content: center; padding: 10px 18px; border: 1px solid transparent; border-radius: 6px; font-weight: 750; text-align: center; text-decoration: none; }
.button-primary { color: #fff; background: var(--coral); }
.button-primary:hover { color: #fff; background: #cc4d32; }
.button-secondary { color: #e9f3f2; border-color: #517271; background: transparent; }
.button-secondary:hover { color: #fff; border-color: #80a4a2; background: rgba(255,255,255,.06); }

.content-shell { padding-block: 56px 88px; }
.content-shell > :first-child { margin-top: 0; }
.content-shell h2 { margin: 58px 0 18px; color: var(--dark); font-size: 28px; line-height: 1.28; letter-spacing: 0; }
.content-shell h3 { margin: 34px 0 12px; color: #244044; font-size: 20px; line-height: 1.35; letter-spacing: 0; }
.content-shell p, .content-shell li { max-width: 900px; }
.content-shell blockquote { margin: 28px 0; padding: 18px 20px; border-left: 4px solid var(--teal); color: #33494d; background: var(--soft); }
.content-shell blockquote p { margin: 0; }
.content-shell hr { height: 1px; margin: 54px 0; border: 0; background: var(--line); }
.content-shell code { padding: 2px 5px; border-radius: 4px; color: #174c4c; background: #edf4f3; font-size: .9em; overflow-wrap: anywhere; }
.content-shell pre { overflow-x: auto; margin: 22px 0; padding: 20px; border-radius: 7px; color: #dcebea; background: var(--code); box-shadow: var(--shadow); }
.content-shell pre code { padding: 0; color: inherit; background: transparent; }
.content-shell table { display: table; width: 100%; margin: 22px 0 30px; border-collapse: collapse; font-size: 14px; }
.content-shell th, .content-shell td { padding: 13px 14px; border: 1px solid var(--line); text-align: left; vertical-align: top; }
.content-shell th { color: #274447; background: var(--soft); }
.content-shell tbody tr:nth-child(even) { background: #fbfcfc; }

.matrix-intro { display: grid; grid-template-columns: minmax(0, 1fr) minmax(320px, .8fr); gap: 38px; align-items: center; margin-bottom: 42px; }
.matrix-intro-copy { padding: 28px 0; }
.matrix-intro-copy strong { display: block; margin-bottom: 10px; color: var(--teal-dark); font-size: 19px; }
.matrix-intro-copy p { margin: 0; color: var(--muted); }
.tool-preview { display: block; overflow: hidden; border: 1px solid var(--line); border-radius: 8px; background: #081722; box-shadow: var(--shadow); }
.tool-preview img { display: block; width: 100%; aspect-ratio: 16 / 9; object-fit: cover; }
.matrix-grid { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 16px; margin: 24px 0 42px; }
.matrix-card { min-height: 168px; display: flex; flex-direction: column; padding: 22px; border: 1px solid var(--line); border-radius: 8px; color: var(--ink); background: #fff; text-decoration: none; transition: transform .16s ease, border-color .16s ease, box-shadow .16s ease; }
.matrix-card:hover { transform: translateY(-2px); border-color: #79aaa6; color: var(--ink); box-shadow: var(--shadow); }
.matrix-card small { color: var(--coral); font-size: 11px; font-weight: 800; }
.matrix-card strong { margin-top: 8px; color: var(--dark); font-size: 19px; }
.matrix-card span { margin-top: 8px; color: var(--muted); font-size: 14px; line-height: 1.65; }
.matrix-card em { margin-top: auto; padding-top: 14px; color: var(--teal-dark); font-size: 13px; font-style: normal; font-weight: 750; }
.path-strip { display: grid; grid-template-columns: repeat(4, 1fr); margin: 26px 0 42px; border: 1px solid var(--line); border-radius: 8px; overflow: hidden; }
.path-strip > div { min-height: 128px; padding: 20px; border-right: 1px solid var(--line); background: #fff; }
.path-strip > div:last-child { border-right: 0; }
.path-strip strong, .path-strip span { display: block; }
.path-strip strong { color: var(--teal-dark); font-size: 13px; }
.path-strip span { margin-top: 8px; color: var(--muted); font-size: 13px; }
.decision-band { display: flex; align-items: center; justify-content: space-between; gap: 26px; margin: 54px 0 0; padding: 26px 28px; border: 1px solid #bfd6d3; border-radius: 8px; background: var(--soft); }
.decision-band strong { display: block; color: var(--dark); font-size: 20px; }
.decision-band p { margin: 6px 0 0; color: var(--muted); font-size: 14px; }
.decision-actions { display: flex; gap: 10px; flex: 0 0 auto; }
.decision-actions .button-secondary { color: var(--teal-dark); border-color: #8db7b3; }
.decision-actions .button-secondary:hover { color: var(--dark); background: #fff; }

.site-footer { color: #c4d5d4; background: var(--dark); }
.footer-grid { display: grid; grid-template-columns: 1.35fr .8fr .8fr; gap: 68px; padding-block: 50px 34px; }
.footer-grid strong { display: block; margin-bottom: 12px; color: #fff; font-size: 14px; }
.footer-grid p { max-width: 440px; margin: 0; color: #94acab; font-size: 13px; }
.footer-grid nav { display: grid; align-content: start; gap: 8px; }
.footer-grid a { color: #b7cac9; font-size: 13px; text-decoration: none; }
.footer-grid a:hover { color: #fff; }
.footer-bottom { display: flex; justify-content: space-between; gap: 24px; padding-block: 18px 26px; border-top: 1px solid rgba(255,255,255,.09); color: #809b99; font-size: 12px; }
.footer-bottom a { color: #9db6b4; }

@media (max-width: 900px) {
  .site-header-inner { flex-wrap: wrap; gap: 10px 14px; padding-block: 10px; }
  .site-nav { order: 3; width: 100%; gap: 20px; margin: 0; overflow-x: auto; white-space: nowrap; scrollbar-width: none; }
  .site-nav::-webkit-scrollbar { display: none; }
  .header-action { margin-left: auto; }
  .page-hero-inner { grid-template-columns: 1fr; gap: 28px; min-height: 0; padding-block: 44px; }
  .page-hero h1 { font-size: 35px; }
  .hero-actions { flex-direction: row; min-width: 0; }
  .matrix-intro { grid-template-columns: 1fr; }
  .path-strip { grid-template-columns: repeat(2, 1fr); }
  .path-strip > div:nth-child(2) { border-right: 0; }
  .path-strip > div:nth-child(-n+2) { border-bottom: 1px solid var(--line); }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 40px; }
  .footer-grid > div { grid-column: 1 / -1; }
}

@media (max-width: 620px) {
  .shell { width: min(calc(100% - 28px), var(--shell)); }
  .site-brand small { display: none; }
  .site-brand strong { font-size: 13px; }
  .header-action { min-height: 36px; padding-inline: 12px; font-size: 12px; }
  .page-hero h1 { font-size: 30px; }
  .page-hero p { font-size: 15px; }
  .hero-actions { flex-direction: column; }
  .content-shell { padding-block: 38px 64px; }
  .content-shell h2 { margin-top: 44px; font-size: 24px; }
  .content-shell table { display: block; overflow-x: auto; white-space: nowrap; }
  .matrix-grid { grid-template-columns: 1fr; }
  .path-strip { grid-template-columns: 1fr; }
  .path-strip > div { border-right: 0; border-bottom: 1px solid var(--line); }
  .path-strip > div:last-child { border-bottom: 0; }
  .decision-band { display: block; padding: 22px; }
  .decision-actions { flex-direction: column; margin-top: 18px; }
  .footer-grid { grid-template-columns: 1fr; gap: 30px; }
  .footer-grid > div { grid-column: auto; }
  .footer-bottom { display: block; }
  .footer-bottom a { display: inline-block; margin-top: 8px; }
}