:root {
  --blue: #4d6bfe;
  --ink: #1b1f26;
  --muted: #7b8aa3;
  --line: rgba(120, 140, 180, 0.18);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font: 15px/1.75 "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  color: var(--ink);
  background:
    radial-gradient(900px 500px at 12% 0%, #e9f0ff 0%, rgba(233, 240, 255, 0) 60%),
    linear-gradient(180deg, #f8faff 0%, #ffffff 40%);
}

.bg-grid {
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, rgba(120, 150, 200, 0.08) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(120, 150, 200, 0.08) 1px, transparent 1px);
  background-size: 96px 96px;
  mask-image: radial-gradient(80% 60% at 50% 0%, #000 30%, transparent 100%);
  -webkit-mask-image: radial-gradient(80% 60% at 50% 0%, #000 30%, transparent 100%);
}

.topbar {
  position: relative;
  z-index: 5;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 20px clamp(18px, 5vw, 56px);
}

.brand { display: inline-flex; align-items: center; gap: 9px; text-decoration: none; }
.brand-text { font-size: 22px; font-weight: 600; color: var(--blue); }

.top-right { display: flex; align-items: center; gap: 20px; }
.ghost-link { color: #3a4252; text-decoration: none; font-size: 14px; }
.ghost-link:hover { color: var(--blue); }

.lang { display: flex; padding: 3px; border: 1px solid var(--line); border-radius: 999px; background: rgba(255,255,255,.75); }
.lang-btn { border: 0; background: none; padding: 5px 14px; border-radius: 999px; font: inherit; font-size: 13px; color: var(--muted); cursor: pointer; }
.lang-btn.is-on { background: #fff; color: var(--ink); box-shadow: 0 2px 8px rgba(60,90,150,.12); }

.wrap { position: relative; z-index: 4; max-width: 860px; margin: 0 auto; padding: 26px 20px 90px; }

h1 { margin: 18px 0 10px; font-size: clamp(26px, 4vw, 38px); font-weight: 600; letter-spacing: .02em; }
.lead { margin: 0 0 26px; color: var(--muted); }

.cta { display: flex; gap: 12px; flex-wrap: wrap; margin-bottom: 34px; }
.btn {
  display: inline-block;
  padding: 11px 22px;
  border-radius: 999px;
  border: 1px solid rgba(120,140,180,.2);
  background: #fff;
  color: #3a4252;
  text-decoration: none;
  font-size: 14px;
  transition: transform .18s ease, box-shadow .18s ease;
}
.btn:hover { transform: translateY(-1px); box-shadow: 0 10px 24px rgba(60,90,150,.12); }
.btn.primary { background: var(--blue); border-color: var(--blue); color: #fff; }
.btn.primary:hover { box-shadow: 0 12px 26px rgba(77,107,254,.35); }

.card {
  padding: 24px 26px;
  margin-bottom: 20px;
  background: rgba(255,255,255,.9);
  border: 1px solid rgba(255,255,255,.9);
  border-radius: 18px;
  box-shadow: 0 16px 40px rgba(50,80,140,.08);
}
.card h2 { margin: 0 0 14px; font-size: 18px; }
.card h3 { margin: 20px 0 8px; font-size: 14px; color: var(--muted); font-weight: 600; }

.steps { margin: 0; padding-left: 20px; }
.steps li { margin: 6px 0; }

pre {
  margin: 0;
  padding: 14px 16px;
  background: #0f1420;
  color: #d7e2f5;
  border-radius: 12px;
  overflow-x: auto;
  font: 13px/1.7 "SFMono-Regular", Consolas, "Liberation Mono", monospace;
}

table { width: 100%; border-collapse: collapse; }
th, td { padding: 9px 0; border-bottom: 1px solid var(--line); text-align: left; font-weight: 400; vertical-align: top; }
th { width: 140px; color: var(--muted); }
tr:last-child th, tr:last-child td { border-bottom: 0; }
code { font: 13px "SFMono-Regular", Consolas, monospace; background: #f2f5fb; padding: 1px 6px; border-radius: 5px; }
pre code { background: none; padding: 0; color: inherit; }

footer { margin-top: 26px; color: var(--muted); font-size: 13px; }

@media (max-width: 600px) {
  .card { padding: 18px; }
  th { width: 110px; }
}