:root {
  --paper: #f5f2ea;
  --paper-soft: #fbfaf6;
  --paper-raise: #ece8dd;
  --ink: #121412;
  --ink-muted: #4d504b;
  --ink-dim: #81857d;
  --line: #1719151c;
  --line-strong: #17191533;
  --sky: #8fafc1;
  --sky-deep: #4f7f99;
  --sky-soft: #dce8ed;
  --sky-wash: #eef6f7;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --mono: "SF Mono", ui-monospace, monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  background:
    linear-gradient(90deg, #15171608 0 1px, transparent 1px 100%),
    radial-gradient(ellipse at 74% 10%, #dce8ed7a 0 16%, transparent 52%),
    linear-gradient(180deg, var(--paper-soft) 0%, var(--paper) 44%, #eef1ed 100%);
  background-size: 124px 124px, auto, auto;
  color: var(--ink);
  font-family: var(--sans);
  font-size: 15px;
  line-height: 1.78;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--sky-deep); text-decoration: none; }
a:hover { text-decoration: underline; }
a:focus-visible, button:focus-visible { outline: 2px solid var(--sky-deep); outline-offset: 3px; }
p, h1, h2, h3, h4, ul { margin: 0; }

/* ---------- masthead ---------- */
.masthead {
  position: sticky;
  top: 0;
  z-index: 40;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  min-height: 72px;
  padding: 0 40px;
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--paper-soft) 86%, transparent);
  backdrop-filter: blur(16px) saturate(1.04);
}
.brand { display: flex; align-items: center; gap: 12px; height: 30px; }
.brand img { height: 30px; width: auto; display: block; }
.brand b { font-weight: 700; letter-spacing: 0.01em; }
.brand .sub {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--ink-dim);
  padding-left: 12px;
  margin-left: 4px;
  border-left: 1px solid var(--line-strong);
}
.masthead .back { font-family: var(--mono); font-size: 12px; letter-spacing: 0.04em; color: var(--ink-muted); }

/* ---------- shell ---------- */
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 40px; }

.lead { padding: 64px 0 30px; border-bottom: 1px solid var(--line); }
.kicker {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--sky-deep);
}
.lead h1 { font-size: 40px; line-height: 1.16; letter-spacing: -0.01em; margin: 16px 0 18px; font-weight: 700; }
.lead .promise { max-width: 720px; color: var(--ink-muted); font-size: 16px; }
.lead .promise strong { color: var(--ink); font-weight: 600; }
.lead .meta { margin-top: 22px; font-family: var(--mono); font-size: 12px; color: var(--ink-dim); letter-spacing: 0.02em; }

/* ---------- two-column layout ---------- */
.layout { display: grid; grid-template-columns: 212px 1fr; gap: 56px; align-items: start; padding: 12px 0 40px; }

.toc { position: sticky; top: 96px; }
.toc .toc-label { font-family: var(--mono); font-size: 11px; letter-spacing: 0.16em; text-transform: uppercase; color: var(--ink-dim); margin-bottom: 14px; }
.toc ol { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 2px; counter-reset: toc; }
.toc a {
  display: flex; gap: 10px; align-items: baseline;
  padding: 7px 10px; border-radius: 8px;
  color: var(--ink-muted); font-size: 13.5px;
  transition: background 0.2s var(--ease), color 0.2s var(--ease);
}
.toc a:hover { background: var(--sky-wash); color: var(--ink); text-decoration: none; }
.toc a .n { counter-increment: toc; font-family: var(--mono); font-size: 11px; color: var(--sky-deep); min-width: 16px; }

/* ---------- sections ---------- */
main { min-width: 0; }
.sec { scroll-margin-top: 92px; padding: 38px 0; border-top: 1px solid var(--line); }
.sec:first-child { border-top: none; padding-top: 18px; }
.sec > .kicker { margin-bottom: 8px; }
.sec h2 { font-size: 26px; font-weight: 700; letter-spacing: -0.005em; margin-bottom: 6px; }
.sec h3 { font-size: 16px; font-weight: 650; margin: 26px 0 8px; }
.sec p { color: var(--ink-muted); margin: 10px 0; max-width: 760px; }
.sec p.intro { color: var(--ink); font-size: 16px; }
.sec ul { max-width: 760px; margin: 8px 0; padding: 0; list-style: none; display: flex; flex-direction: column; gap: 9px; }
.sec li { position: relative; padding-left: 20px; color: var(--ink-muted); }
.sec li::before { content: ""; position: absolute; left: 4px; top: 11px; width: 5px; height: 5px; border-radius: 50%; background: var(--sky-deep); }
.sec li strong, .sec p strong { color: var(--ink); font-weight: 600; }
.sec code { font-family: var(--mono); font-size: 12.5px; background: var(--paper-raise); padding: 1px 6px; border-radius: 5px; }

/* highlight boxes */
.callout {
  margin: 18px 0; padding: 18px 20px;
  background: var(--sky-wash);
  border: 1px solid var(--sky-soft);
  border-left: 3px solid var(--sky-deep);
  border-radius: 10px;
}
.callout .tag { font-family: var(--mono); font-size: 11px; letter-spacing: 0.12em; text-transform: uppercase; color: var(--sky-deep); display: block; margin-bottom: 6px; }
.callout p, .callout ul { margin: 6px 0; }
.callout.warm { background: #faf6ec; border-color: #e8dcc0; border-left-color: var(--ink-muted); }
.callout.warm .tag { color: var(--ink-muted); }

/* provider rows */
.prov { display: flex; flex-direction: column; gap: 4px; padding: 14px 0; border-bottom: 1px dashed var(--line-strong); }
.prov:last-of-type { border-bottom: none; }
.prov b { font-size: 15px; }

/* ---------- footer ---------- */
.foot { border-top: 1px solid var(--line); margin-top: 24px; padding: 34px 0 70px; color: var(--ink-dim); font-size: 13px; }
.foot p { margin: 6px 0; max-width: 760px; }
.foot .disc { font-style: italic; }

/* ---------- breadcrumb ---------- */
.crumb { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; font-family: var(--mono); font-size: 12px; letter-spacing: 0.03em; color: var(--ink-dim); padding-top: 38px; }
.crumb a { color: var(--ink-muted); }
.crumb .sep { color: var(--line-strong); }
.crumb .cur { color: var(--ink); }

/* ---------- service hero (per-service pages) ---------- */
.svc-hero { padding: 14px 0 24px; border-bottom: 1px solid var(--line); }
.svc-hero h1 { font-size: 34px; line-height: 1.18; letter-spacing: -0.01em; margin: 12px 0 12px; font-weight: 700; }
.svc-hero .scope { max-width: 720px; color: var(--ink-muted); font-size: 16px; }
.svc-hero .meta { margin-top: 18px; font-family: var(--mono); font-size: 12px; color: var(--ink-dim); letter-spacing: 0.02em; }
.docnav { display: flex; gap: 10px; margin-top: 20px; flex-wrap: wrap; }
.docnav a { font-family: var(--mono); font-size: 12px; letter-spacing: 0.04em; padding: 7px 14px; border: 1px solid var(--line-strong); border-radius: 999px; color: var(--ink-muted); }
.docnav a:hover { background: var(--sky-wash); color: var(--ink); text-decoration: none; }

/* section band label inside a service page */
.docband { display: flex; align-items: center; gap: 14px; margin: 6px 0 0; }
.docband .l { height: 1px; flex: 1; background: var(--line); }
.docband .t { font-family: var(--mono); font-size: 12px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--sky-deep); }

/* ---------- hub: service cards ---------- */
.hub-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 16px; padding: 28px 0 6px; }
.svc-card { display: block; padding: 22px 22px 20px; background: var(--paper-soft); border: 1px solid var(--line); border-radius: 14px; transition: border-color 0.2s var(--ease), transform 0.2s var(--ease), box-shadow 0.2s var(--ease); }
.svc-card:hover { border-color: var(--sky); transform: translateY(-2px); box-shadow: 0 14px 40px #1517160f; text-decoration: none; }
.svc-card .no { font-family: var(--mono); font-size: 11px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--sky-deep); }
.svc-card h3 { font-size: 19px; font-weight: 700; margin: 8px 0 6px; color: var(--ink); }
.svc-card p { color: var(--ink-muted); font-size: 14px; margin: 0; }
.svc-card .docs { margin-top: 14px; font-family: var(--mono); font-size: 11.5px; color: var(--ink-dim); letter-spacing: 0.03em; }
.hub-cross { display: flex; flex-wrap: wrap; gap: 12px; padding: 22px 0 4px; }
.hub-cross a { font-family: var(--mono); font-size: 12.5px; padding: 9px 16px; border: 1px solid var(--line-strong); border-radius: 999px; color: var(--ink-muted); }
.hub-cross a:hover { background: var(--sky-wash); color: var(--ink); text-decoration: none; }
.hub-cross a.warm { border-color: var(--sky); color: var(--sky-deep); }

/* ---------- responsive ---------- */
@media (max-width: 880px) {
  .hub-grid { grid-template-columns: 1fr; }
  .crumb { padding-top: 22px; }
  .svc-hero h1 { font-size: 27px; }
  .masthead { padding: 0 20px; }
  .brand .sub { display: none; }
  .wrap { padding: 0 22px; }
  .lead { padding: 40px 0 24px; }
  .lead h1 { font-size: 30px; }
  .layout { grid-template-columns: 1fr; gap: 8px; }
  .toc { position: static; margin: 6px 0 8px; padding: 14px 16px; background: var(--paper-soft); border: 1px solid var(--line); border-radius: 12px; }
  .toc ol { flex-direction: column; }
}