:root {
  color-scheme: light;
  --brand: #165dff;
  --brand-dark: #0f46c8;
  --ink: #111827;
  --muted: #64748b;
  --line: #e2e8f0;
  --page: #f6f8fb;
  --panel: #ffffff;
}

* {
  box-sizing: border-box;
}

html {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--page);
  text-size-adjust: 100%;
}

body {
  margin: 0;
  min-height: 100vh;
  font-size: 16px;
  line-height: 1.75;
}

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

.site-header {
  border-bottom: 1px solid rgba(226, 232, 240, 0.9);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(16px);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
  padding: 18px 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  letter-spacing: 0;
}

.brand-logo {
  display: block;
  width: 32px;
  height: 32px;
  border-radius: 8px;
  object-fit: cover;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 20px;
  color: var(--muted);
  font-size: 14px;
}

.nav-links a:hover {
  color: var(--brand);
}

.hero {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
  padding: 56px 0 28px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--brand);
  font-size: 14px;
  font-weight: 700;
}

h1 {
  margin: 0;
  font-size: clamp(30px, 5vw, 48px);
  line-height: 1.15;
  letter-spacing: 0;
}

.summary {
  max-width: 760px;
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 17px;
}

.meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
  color: var(--muted);
  font-size: 14px;
}

.meta span {
  padding: 6px 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: #fff;
}

.layout {
  display: grid;
  grid-template-columns: 248px minmax(0, 1fr);
  gap: 28px;
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
  padding: 0 0 72px;
}

.toc {
  position: sticky;
  top: 20px;
  align-self: start;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
}

.toc-title {
  margin: 0 0 12px;
  font-size: 14px;
  font-weight: 700;
}

.toc ol {
  display: grid;
  gap: 8px;
  margin: 0;
  padding-left: 20px;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.55;
}

.toc a:hover {
  color: var(--brand);
}

.article {
  padding: 38px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--panel);
  box-shadow: 0 18px 45px rgba(15, 23, 42, 0.06);
}

.article section + section {
  margin-top: 34px;
  padding-top: 30px;
  border-top: 1px solid var(--line);
}

h2 {
  margin: 0 0 16px;
  font-size: 22px;
  line-height: 1.35;
  letter-spacing: 0;
}

p {
  margin: 0 0 14px;
  color: #334155;
}

ol,
ul {
  margin: 0 0 14px;
  padding-left: 1.35em;
  color: #334155;
}

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

.notice {
  margin: 0 0 26px;
  padding: 16px 18px;
  border-left: 4px solid var(--brand);
  border-radius: 8px;
  background: #eef5ff;
  color: #1e3a8a;
}

.footer {
  border-top: 1px solid var(--line);
  background: #fff;
}

.footer-inner {
  width: min(1120px, calc(100% - 40px));
  margin: 0 auto;
  padding: 24px 0;
  color: var(--muted);
  font-size: 14px;
}

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

  .toc {
    position: static;
  }
}

@media (max-width: 640px) {
  .nav {
    width: min(100% - 28px, 1120px);
    align-items: flex-start;
    gap: 14px;
  }

  .nav-links {
    gap: 12px;
  }

  .hero,
  .layout,
  .footer-inner {
    width: min(100% - 28px, 1120px);
  }

  .hero {
    padding-top: 36px;
  }

  .article {
    padding: 24px 18px;
  }

  h2 {
    font-size: 20px;
  }
}