:root {
  --brand: #3d52d5;
  --brand-deep: #2a3bb0;
  --brand-soft: #e8ecff;
  --ink: #12141c;
  --muted: #5c6378;
  --line: #e4e7f0;
  --paper: #f6f7fb;
  --card: #ffffff;
  --gold: #b8892d;
  --radius: 16px;
  --shadow: 0 18px 50px rgba(45, 55, 120, 0.08);
  --font: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --display: "Songti SC", "Noto Serif SC", "STSong", serif;
}

@media (prefers-color-scheme: dark) {
  :root {
    --ink: #f2f4fb;
    --muted: #a8b0c7;
    --line: #2a3148;
    --paper: #0f121c;
    --card: #171c2b;
    --brand-soft: #1c2440;
    --shadow: 0 18px 50px rgba(0, 0, 0, 0.35);
  }
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font);
  color: var(--ink);
  background:
    radial-gradient(1200px 600px at 10% -10%, rgba(61, 82, 213, 0.16), transparent 55%),
    radial-gradient(900px 500px at 100% 0%, rgba(184, 137, 45, 0.1), transparent 45%),
    linear-gradient(180deg, var(--paper), var(--paper));
  line-height: 1.7;
  min-height: 100vh;
}

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

.wrap {
  width: min(960px, calc(100% - 32px));
  margin: 0 auto;
}

/* —— Header —— */
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  backdrop-filter: blur(14px);
  background: color-mix(in srgb, var(--paper) 82%, transparent);
  border-bottom: 1px solid var(--line);
}
.site-header .inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 0;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--ink);
  text-decoration: none;
  font-weight: 650;
  letter-spacing: 0.02em;
}
.brand:hover { text-decoration: none; }
.brand-mark {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: linear-gradient(145deg, var(--brand), var(--brand-deep));
  color: #fff;
  display: grid;
  place-items: center;
  font-family: var(--display);
  font-size: 16px;
  box-shadow: 0 8px 20px rgba(61, 82, 213, 0.28);
}
.nav {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
  font-size: 14px;
}
.nav a { color: var(--muted); }
.nav a:hover { color: var(--brand); }

/* —— Hero —— */
.hero {
  padding: 56px 0 28px;
}
.hero-kicker {
  display: inline-block;
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--brand-soft);
  color: var(--brand-deep);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.04em;
  margin-bottom: 18px;
}
@media (prefers-color-scheme: dark) {
  .hero-kicker { color: #b8c3ff; }
}
.hero h1 {
  margin: 0 0 12px;
  font-family: var(--display);
  font-size: clamp(34px, 6vw, 52px);
  line-height: 1.15;
  letter-spacing: 0.02em;
  font-weight: 700;
}
.hero .tagline {
  margin: 0 0 8px;
  font-size: clamp(18px, 2.6vw, 22px);
  color: var(--gold);
  font-weight: 600;
}
.hero .sub {
  margin: 0 0 28px;
  max-width: 34em;
  color: var(--muted);
  font-size: 16px;
}
.cta-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 18px;
  border-radius: 12px;
  font-size: 15px;
  font-weight: 600;
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
}
.btn:hover { text-decoration: none; }
.btn-primary {
  background: linear-gradient(145deg, var(--brand), var(--brand-deep));
  color: #fff;
  box-shadow: 0 10px 24px rgba(61, 82, 213, 0.28);
}
.btn-ghost {
  background: var(--card);
  color: var(--ink);
  border-color: var(--line);
}

/* —— Sections —— */
.section {
  padding: 28px 0 8px;
}
.section h2 {
  margin: 0 0 8px;
  font-size: 22px;
  letter-spacing: 0.02em;
}
.section .lead {
  margin: 0 0 20px;
  color: var(--muted);
  font-size: 15px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}
@media (max-width: 720px) {
  .grid { grid-template-columns: 1fr; }
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 20px 18px;
  box-shadow: var(--shadow);
}
.card h3 {
  margin: 0 0 8px;
  font-size: 17px;
}
.card p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}
.card .icon {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: var(--brand-soft);
  color: var(--brand);
  display: grid;
  place-items: center;
  margin-bottom: 12px;
  font-size: 16px;
  font-weight: 700;
}

.meta-box {
  margin-top: 24px;
  padding: 18px;
  border-radius: var(--radius);
  border: 1px dashed var(--line);
  background: color-mix(in srgb, var(--card) 70%, transparent);
  font-size: 14px;
  color: var(--muted);
}
.meta-box strong { color: var(--ink); }
.meta-box dl {
  display: grid;
  grid-template-columns: 110px 1fr;
  gap: 8px 12px;
  margin: 12px 0 0;
}
.meta-box dt { color: var(--muted); }
.meta-box dd { margin: 0; color: var(--ink); }

.note {
  margin-top: 16px;
  padding: 14px 16px;
  border-left: 3px solid var(--brand);
  background: var(--brand-soft);
  border-radius: 0 12px 12px 0;
  color: var(--muted);
  font-size: 14px;
}

/* —— Legal pages —— */
.doc {
  padding: 36px 0 48px;
}
.doc header {
  margin-bottom: 28px;
}
.doc h1 {
  margin: 0 0 10px;
  font-family: var(--display);
  font-size: clamp(28px, 4vw, 36px);
  line-height: 1.25;
}
.doc .meta {
  color: var(--muted);
  font-size: 13px;
}
.doc-body {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 20px;
  padding: clamp(20px, 4vw, 36px);
  box-shadow: var(--shadow);
}
.doc-body h2 {
  margin: 28px 0 10px;
  font-size: 18px;
}
.doc-body h2:first-child { margin-top: 0; }
.doc-body h3 {
  margin: 18px 0 8px;
  font-size: 16px;
}
.doc-body p, .doc-body li {
  color: var(--muted);
  font-size: 15px;
}
.doc-body ul { padding-left: 1.2em; }
.doc-body li { margin: 6px 0; }

/* —— Footer —— */
.site-footer {
  margin-top: 48px;
  padding: 28px 0 40px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
  text-align: center;
}
.site-footer .links {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 8px 16px;
  margin-bottom: 12px;
}
.site-footer a { color: var(--muted); }
.site-footer a:hover { color: var(--brand); }
.icp a {
  color: var(--brand);
  font-weight: 600;
}