:root {
  --page: #f6f8fc;
  --surface: #fff;
  --ink: #152033;
  --muted: #61708a;
  --line: #e4eaf3;
  --brand: #2563eb;
  --brand-soft: #eff6ff;
  --good: #097a4a;
  --warn: #8a5a00;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  color: var(--ink);
  background: var(--page);
  font: 16px/1.7 Inter, "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
}

a { color: var(--brand); font-weight: 650; text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { width: min(980px, calc(100% - 36px)); margin: 0 auto; }

header { background: rgba(255,255,255,.9); border-bottom: 1px solid var(--line); }
.topbar { display: flex; align-items: center; justify-content: space-between; gap: 18px; min-height: 68px; }
.brand { display: inline-flex; align-items: center; gap: 9px; color: var(--ink); font-weight: 800; text-decoration: none; }
.mark { display: grid; width: 31px; height: 31px; place-items: center; border-radius: 9px; color: #fff; background: linear-gradient(135deg,#4f46e5,#0ea5e9); font-size: 12px; }
nav { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 4px 14px; font-size: 14px; }
nav a { color: var(--muted); }

main { padding: 52px 0 70px; }
.eyebrow { color: var(--brand); font-size: 13px; font-weight: 800; letter-spacing: .08em; text-transform: uppercase; }
h1 { max-width: 800px; margin: 8px 0 12px; font-size: clamp(34px, 6vw, 54px); line-height: 1.14; letter-spacing: -.045em; }
h2 { margin: 42px 0 14px; font-size: 25px; line-height: 1.3; letter-spacing: -.025em; }
h3 { margin: 0 0 8px; font-size: 17px; }
p { margin: 0 0 13px; color: var(--muted); }
.lead { max-width: 740px; font-size: 18px; }
.grid { display: grid; grid-template-columns: repeat(2, minmax(0,1fr)); gap: 14px; }
.card, .callout, .step { border: 1px solid var(--line); border-radius: 16px; background: var(--surface); }
.card { padding: 22px; }
.card p:last-child, .callout p:last-child { margin-bottom: 0; }
.card:hover { border-color: #bad2ff; box-shadow: 0 10px 30px rgba(40,80,150,.08); }
.card strong { display: block; margin-bottom: 5px; }
.card .arrow { color: var(--brand); font-weight: 800; }
.steps { display: grid; gap: 12px; }
.step { display: grid; grid-template-columns: 34px 1fr; gap: 14px; padding: 19px; }
.num { display: grid; width: 29px; height: 29px; place-items: center; border-radius: 50%; color: var(--brand); background: var(--brand-soft); font-size: 13px; font-weight: 800; }
.callout { margin: 22px 0; padding: 18px 20px; border-color: #c9dcff; background: var(--brand-soft); }
.callout.warning { border-color: #f0d493; background: #fff9e9; }
.callout.warning p, .callout.warning strong { color: var(--warn); }
.callout.success { border-color: #b8e5cf; background: #effbf5; }
.callout.success p, .callout.success strong { color: var(--good); }
.endpoint, code { font-family: "SFMono-Regular", Consolas, monospace; }
.endpoint { display: block; overflow-wrap: anywhere; padding: 11px 12px; border: 1px solid var(--line); border-radius: 9px; background: #fbfcff; color: var(--ink); }
pre { overflow-x: auto; margin: 0; padding: 15px; border-radius: 10px; background: #101827; color: #dbeafe; font: 13px/1.6 "SFMono-Regular", Consolas, monospace; }
code { padding: 1px 5px; border-radius: 5px; color: #1d4ed8; background: var(--brand-soft); font-size: .9em; }
pre code { padding: 0; color: inherit; background: transparent; }
ul { margin: 0; padding-left: 22px; color: var(--muted); }
li + li { margin-top: 7px; }
.actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 22px; }
.button { display: inline-flex; align-items: center; justify-content: center; min-height: 42px; padding: 8px 15px; border-radius: 10px; color: #fff; background: var(--brand); text-decoration: none; }
.button:hover { color: #fff; background: #1d4ed8; text-decoration: none; }
.button.secondary { color: var(--brand); background: var(--surface); border: 1px solid #b9d0fb; }
.button.secondary:hover { color: #1d4ed8; background: var(--brand-soft); }
.toc { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 21px; }
.toc a { padding: 5px 10px; border-radius: 99px; background: var(--brand-soft); font-size: 13px; }
footer { padding: 28px 0 38px; color: #8a96a8; font-size: 13px; text-align: center; }

@media (max-width: 680px) {
  .topbar { align-items: flex-start; flex-direction: column; padding: 14px 0; }
  nav { justify-content: flex-start; }
  main { padding-top: 38px; }
  .grid { grid-template-columns: 1fr; }
  .card, .step { padding: 18px; }
}