:root {
  color-scheme: light;
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #eff6ff;
  --ink: #111827;
  --body: #374151;
  --muted: #6b7280;
  --line: #e5e7eb;
  --page: #f8fafc;
  --white: #ffffff;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  min-width: 320px;
  margin: 0;
  color: var(--body);
  background: var(--page);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.8;
  text-rendering: optimizeLegibility;
}

a {
  color: inherit;
  text-decoration: none;
}

.site-header {
  border-bottom: 1px solid rgba(229, 231, 235, 0.9);
  background: var(--white);
}

.site-header__inner {
  display: flex;
  align-items: center;
  width: min(1160px, calc(100% - 48px));
  min-height: 62px;
  margin: 0 auto;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
}

.brand__mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: 0 0 auto;
  width: 34px;
  height: 34px;
  overflow: hidden;
  border-radius: 50%;
  background: var(--white);
}

.brand__mark img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: contain;
}

.brand__copy {
  display: grid;
  gap: 1px;
}

.brand__copy strong {
  color: var(--primary);
  font-size: 15px;
  line-height: 1.4;
}

.brand__copy small {
  color: var(--primary);
  font-size: 9px;
  letter-spacing: 0;
  line-height: 1.4;
}

.page-shell {
  padding: 56px 0 84px;
}

.page-grid {
  display: grid;
  grid-template-columns: 192px minmax(0, 780px);
  gap: 64px;
  align-items: start;
  width: min(1036px, calc(100% - 48px));
  margin: 0 auto;
}

.toc {
  position: sticky;
  top: 28px;
}

.toc__label {
  margin: 0 0 16px;
  color: var(--ink);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.1em;
}

.toc nav {
  display: grid;
  gap: 4px;
}

.toc__link {
  display: block;
  padding: 7px 12px;
  border-left: 2px solid transparent;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
  transition: color 160ms ease, border-color 160ms ease, background 160ms ease;
}

.toc__link:hover,
.toc__link.is-active {
  border-left-color: var(--primary);
  color: var(--primary-dark);
  background: var(--primary-light);
}

.document {
  min-width: 0;
  padding: 58px 68px 42px;
  border: 1px solid var(--line);
  background: var(--white);
  box-shadow: 0 18px 45px rgba(15, 23, 42, 0.06);
}

.document__header {
  padding-bottom: 34px;
  border-bottom: 1px solid var(--line);
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--primary);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.16em;
}

h1,
h2,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 16px;
  color: var(--ink);
  font-size: clamp(30px, 4vw, 42px);
  letter-spacing: 0;
  line-height: 1.25;
}

.document__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 24px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.5;
}

.document__section {
  padding-top: 36px;
  scroll-margin-top: 28px;
}

.document__section h2 {
  display: flex;
  gap: 12px;
  align-items: baseline;
  margin-bottom: 16px;
  color: var(--ink);
  font-size: 20px;
  line-height: 1.4;
}

.document__section h2 span {
  color: var(--primary);
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 12px;
  letter-spacing: 0.06em;
}

.document__section p,
.document__section li {
  color: var(--body);
  font-size: 15px;
  line-height: 1.9;
}

.document__section p {
  margin-bottom: 14px;
}

.document__section ul {
  display: grid;
  gap: 10px;
  margin: 12px 0 0;
  padding: 0;
  list-style: none;
}

.document__section li {
  position: relative;
  padding-left: 21px;
}

.document__section li::before {
  position: absolute;
  top: 0.8em;
  left: 2px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--primary);
  content: "";
}

.document__section strong {
  color: var(--ink);
  font-weight: 650;
}

.document__section--contact {
  margin-top: 12px;
  padding: 26px 24px 8px;
  border: 1px solid #dbeafe;
  background: #f8fbff;
}

.contact-list {
  display: grid;
  gap: 8px;
  margin: 20px 0 14px;
}

.contact-list p {
  display: grid;
  grid-template-columns: 88px minmax(0, 1fr);
  gap: 12px;
  margin-bottom: 0;
}

.contact-list strong {
  color: var(--muted);
  font-weight: 500;
}

.contact-list span,
.contact-list a {
  min-width: 0;
  color: var(--ink);
  word-break: break-word;
}

.contact-list a:hover {
  color: var(--primary-dark);
  text-decoration: underline;
}

.document__footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px;
  margin-top: 46px;
  padding-top: 22px;
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 12px;
  line-height: 1.5;
}

@media (max-width: 860px) {
  .page-grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .toc {
    position: static;
    padding: 18px 20px;
    border: 1px solid var(--line);
    background: var(--white);
  }

  .toc nav {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 2px 16px;
  }
}

@media (max-width: 560px) {
  .site-header__inner,
  .page-grid {
    width: min(100% - 32px, 780px);
  }

  .site-header__inner {
    min-height: 68px;
  }

  .page-shell {
    padding: 24px 0 48px;
  }

  .toc {
    padding: 14px 16px;
  }

  .toc nav {
    grid-template-columns: 1fr;
  }

  .document {
    padding: 34px 22px 28px;
  }

  .document__section {
    padding-top: 30px;
  }

  .document__section p,
  .document__section li {
    font-size: 14px;
    line-height: 1.85;
  }

  .document__section--contact {
    padding: 22px 16px 6px;
  }

  .contact-list p {
    grid-template-columns: 74px minmax(0, 1fr);
    gap: 8px;
  }
}