:root {
  color-scheme: light;
  --ink: #172431;
  --muted: #5f6f7e;
  --line: #d8e2eb;
  --paper: #fbfdff;
  --soft: #eef6fc;
  --accent: #3a6d9c;
  --accent-dark: #284d70;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-height: 100vh;
  background: var(--paper);
  color: var(--ink);
  font-family: Inter, "Noto Sans SC", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.7;
}
a { color: var(--accent); text-underline-offset: 3px; }
a:hover { color: var(--accent-dark); }
a:focus-visible, button:focus-visible { outline: 3px solid #98c8ef; outline-offset: 3px; }
.skip-link {
  position: absolute;
  top: -60px;
  left: 16px;
  z-index: 10;
  padding: 10px 14px;
  background: var(--ink);
  color: #fff;
}
.skip-link:focus { top: 12px; }
.site-header {
  position: sticky;
  top: 0;
  z-index: 5;
  display: flex;
  align-items: center;
  gap: 18px;
  min-height: 58px;
  padding: 8px max(18px, calc((100vw - 1040px) / 2));
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--paper) 94%, transparent);
  backdrop-filter: blur(12px);
}
.brand {
  color: var(--ink);
  font-size: 18px;
  font-weight: 800;
  letter-spacing: .14em;
  text-decoration: none;
  text-transform: uppercase;
}
.site-nav {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-left: auto;
  font-size: 14px;
}
.icon-button {
  width: 38px;
  height: 38px;
  flex: none;
  padding: 0;
  border: 0;
  border-radius: 50%;
  background: transparent;
  color: var(--ink);
  cursor: pointer;
  display: grid;
  place-items: center;
  text-decoration: none;
  transition: background .16s ease, color .16s ease, transform .16s ease;
}
.icon-button:hover { background: var(--soft); color: var(--accent-dark); }
.icon-button:active { transform: translateY(1px); }
.icon-button svg { width: 19px; height: 19px; display: block; pointer-events: none; }
.shell { width: min(1040px, calc(100% - 36px)); margin: 0 auto; }
.hero { padding: 64px 0 32px; border-bottom: 1px solid var(--line); }
.eyebrow {
  margin: 0 0 10px;
  color: var(--accent);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .14em;
  text-transform: uppercase;
}
h1 { margin: 0; font-size: clamp(38px, 7vw, 64px); line-height: 1.02; letter-spacing: -.025em; }
.lead { max-width: 760px; margin: 18px 0 0; color: var(--muted); font-size: 18px; }
.meta { margin-top: 18px; color: var(--muted); font-size: 13px; }
.policy-layout { display: grid; grid-template-columns: 230px minmax(0, 1fr); gap: 54px; padding: 38px 0 72px; }
.toc { position: sticky; top: 82px; align-self: start; padding: 18px; border: 1px solid var(--line); background: #fff; }
.toc strong { display: block; margin-bottom: 8px; font-size: 13px; }
.toc a { display: block; padding: 4px 0; font-size: 13px; text-decoration: none; }
.policy section { scroll-margin-top: 86px; padding: 0 0 30px; }
.policy section + section { padding-top: 30px; border-top: 1px solid var(--line); }
h2 { margin: 0 0 12px; font-size: 27px; line-height: 1.25; }
h3 { margin: 22px 0 8px; font-size: 18px; }
p { margin: 0 0 13px; }
ul { margin: 10px 0 16px; padding-left: 22px; }
li + li { margin-top: 7px; }
.notice { padding: 18px 20px; border-left: 4px solid var(--accent); background: var(--soft); }
.notice p:last-child { margin-bottom: 0; }
.contact-card { padding: 20px; border: 1px solid var(--line); background: #fff; }
.site-footer { padding: 24px 0 40px; border-top: 1px solid var(--line); color: var(--muted); font-size: 13px; }
.site-footer .shell { display: flex; flex-wrap: wrap; gap: 14px; align-items: center; }
.site-footer nav { display: flex; flex-wrap: wrap; gap: 14px; margin-left: auto; }
[data-lang="zh"] .lang-en, [data-lang="en"] .lang-zh { display: none; }

@media (max-width: 760px) {
  .site-header { gap: 10px; padding-inline: 14px; }
  .site-nav { gap: 10px; }
  .site-nav .secondary-link { display: none; }
  .hero { padding-top: 42px; }
  .policy-layout { grid-template-columns: 1fr; gap: 24px; padding-top: 24px; }
  .toc { position: static; }
  .site-footer nav { width: 100%; margin-left: 0; }
}

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