:root {
  color-scheme: light;
  --paper: #f8f3ed;
  --paper-deep: #efe6dc;
  --ink: #1e2a3b;
  --muted: #637078;
  --coral: #ff715b;
  --coral-deep: #b43e2f;
  --line: rgba(30, 42, 59, 0.14);
  --white: #fffdfa;
  --shadow: 0 24px 80px rgba(64, 44, 33, 0.1);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 12% 8%, rgba(255, 113, 91, 0.16), transparent 28rem),
    linear-gradient(135deg, rgba(255, 255, 255, 0.72), transparent 42%),
    var(--paper);
  font-family: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 17px;
  line-height: 1.78;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--coral-deep);
  text-underline-offset: 0.22em;
}

a:hover {
  color: var(--ink);
}

a:focus-visible {
  outline: 3px solid rgba(255, 113, 91, 0.42);
  outline-offset: 4px;
  border-radius: 4px;
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 20;
  padding: 10px 14px;
  color: var(--ink);
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 10px;
  box-shadow: var(--shadow);
  transform: translateY(-160%);
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header {
  width: min(1160px, calc(100% - 40px));
  margin: 0 auto;
  padding: 26px 0 12px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  text-decoration: none;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.brand-mark {
  width: 44px;
  height: 44px;
  display: block;
  border-radius: 12px;
  box-shadow: 0 10px 22px rgba(30, 42, 59, 0.18);
}

.site-nav {
  display: flex;
  gap: 18px;
  font-size: 14px;
  font-weight: 600;
}

.site-nav a {
  color: var(--muted);
  text-decoration: none;
}

.site-nav a[aria-current="page"] {
  color: var(--ink);
}

.hero {
  width: min(1160px, calc(100% - 40px));
  margin: 54px auto 48px;
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(260px, 0.42fr);
  gap: clamp(36px, 7vw, 96px);
  align-items: end;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--coral-deep);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

h2,
h3 {
  font-family: "Songti SC", "STSong", serif;
  text-wrap: balance;
}

h1 {
  margin: 0;
  font-size: clamp(42px, 7vw, 84px);
  font-family: "Songti SC", "STSong", serif;
  line-height: 1.02;
  letter-spacing: -0.055em;
}

.hero-line {
  display: block;
  white-space: nowrap;
}

.hero-note {
  margin: 0 0 6px;
  padding: 24px 0 4px 24px;
  border-left: 2px solid var(--coral);
  color: var(--muted);
  font-size: 15px;
}

.hero-note strong {
  display: block;
  margin-bottom: 7px;
  color: var(--ink);
  font-size: 18px;
}

.hero-link {
  display: inline-block;
  margin-top: 12px;
  font-weight: 700;
}

.content-shell {
  width: min(1160px, calc(100% - 40px));
  margin: 0 auto 92px;
  padding: clamp(28px, 5vw, 64px);
  display: grid;
  grid-template-columns: 210px minmax(0, 1fr);
  gap: clamp(36px, 7vw, 92px);
  background: rgba(255, 253, 250, 0.92);
  border: 1px solid rgba(255, 255, 255, 0.94);
  border-radius: 32px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(16px);
}

.toc {
  position: sticky;
  top: 28px;
  align-self: start;
  font-size: 14px;
}

.toc strong {
  display: block;
  margin-bottom: 12px;
  color: var(--ink);
  font-size: 12px;
  letter-spacing: 0.14em;
}

.toc a {
  display: block;
  padding: 7px 0;
  color: var(--muted);
  text-decoration: none;
}

.document {
  min-width: 0;
  max-width: 760px;
}

.document section {
  padding: 0 0 46px;
  scroll-margin-top: 28px;
}

.document section + section {
  padding-top: 42px;
  border-top: 1px solid var(--line);
}

.document h2 {
  margin: 0 0 17px;
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1.2;
  letter-spacing: -0.035em;
}

.document h3 {
  margin: 32px 0 10px;
  font-size: 22px;
}

.document p,
.document ul,
.document ol {
  margin-top: 0;
}

.document li + li {
  margin-top: 8px;
}

.callout {
  margin: 26px 0 0;
  padding: 20px 22px;
  border-radius: 18px;
  background: linear-gradient(135deg, rgba(255, 113, 91, 0.1), rgba(255, 255, 255, 0.46));
  border: 1px solid rgba(255, 113, 91, 0.18);
}

.support-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin: 22px 0 0;
}

.support-item {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: rgba(248, 243, 237, 0.56);
}

.support-item strong {
  display: block;
  margin-bottom: 5px;
}

.site-footer {
  width: min(1160px, calc(100% - 40px));
  margin: -54px auto 0;
  padding: 28px 0 56px;
  display: flex;
  justify-content: space-between;
  gap: 20px;
  color: var(--muted);
  font-size: 13px;
}

@media (max-width: 760px) {
  body {
    font-size: 16px;
  }

  .site-header,
  .hero,
  .content-shell,
  .site-footer {
    width: min(100% - 28px, 680px);
  }

  .site-nav {
    gap: 12px;
    font-size: 13px;
  }

  .hero {
    margin-top: 38px;
    grid-template-columns: 1fr;
    gap: 24px;
  }

  h1 {
    font-size: clamp(38px, 11vw, 54px);
  }

  .hero-note {
    max-width: 36em;
  }

  .content-shell {
    grid-template-columns: 1fr;
    gap: 24px;
    border-radius: 24px;
  }

  .toc {
    position: static;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--line);
    columns: 2;
  }

  .toc strong {
    column-span: all;
  }

  .support-grid {
    grid-template-columns: 1fr;
  }

  .site-footer {
    display: block;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

@media print {
  body {
    background: white;
  }

  .site-header,
  .toc,
  .site-footer {
    display: none;
  }

  .hero,
  .content-shell {
    width: 100%;
    margin: 0;
  }

  .hero {
    display: block;
    padding: 0 0 32px;
  }

  .content-shell {
    display: block;
    padding: 0;
    box-shadow: none;
    border: 0;
  }
}