/* 公开证据页样式（2026-10-23）：纯 CSS、无外部资源、跟随系统深浅色。 */

:root {
  --learn-bg: #fbf8f2;
  --learn-surface: #fffdf8;
  --learn-ink: #26211c;
  --learn-ink-2: #5a5147;
  --learn-muted: #8a7f72;
  --learn-line: #e7ddcf;
  --learn-accent: #8a5a2b;
  --learn-caution: #7a3f1d;
}

@media (prefers-color-scheme: dark) {
  :root {
    --learn-bg: #17130f;
    --learn-surface: #211b15;
    --learn-ink: #f1e9dc;
    --learn-ink-2: #c8bbaa;
    --learn-muted: #9c8f7f;
    --learn-line: #3a3026;
    --learn-accent: #e0b184;
    --learn-caution: #f0b38a;
  }
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--learn-bg);
  color: var(--learn-ink);
  font-family: ui-serif, Georgia, "Songti SC", "Noto Serif CJK SC", serif;
  line-height: 1.7;
}

a { color: var(--learn-accent); text-decoration-thickness: 1px; text-underline-offset: 3px; }
a:hover { text-decoration-thickness: 2px; }

.skip {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--learn-surface);
  padding: 8px 14px;
  z-index: 10;
}
.skip:focus { left: 8px; top: 8px; }

.topbar { border-bottom: 1px solid var(--learn-line); background: var(--learn-surface); }
.topbar-inner {
  max-width: 960px;
  margin: 0 auto;
  padding: 12px 20px;
  display: flex;
  gap: 16px;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
}
.brand { display: inline-flex; gap: 8px; align-items: baseline; text-decoration: none; color: var(--learn-ink); }
.brand-cn { font-size: 22px; letter-spacing: 0.08em; }
.brand-en { font-size: 14px; letter-spacing: 0.14em; text-transform: uppercase; color: var(--learn-muted); }
.topnav { display: flex; gap: 14px; align-items: center; flex-wrap: wrap; font-size: 14px; }
.topnav a { text-decoration: none; color: var(--learn-ink-2); }
.topnav a:hover { color: var(--learn-accent); }
.top-cta {
  border: 1px solid var(--learn-line);
  border-radius: 999px;
  padding: 4px 12px;
  color: var(--learn-ink) !important;
}

.wrap { max-width: 960px; margin: 0 auto; padding: 0 20px 48px; }

.learn-breadcrumb { font-size: 13px; color: var(--learn-muted); padding: 18px 0 4px; }
.learn-breadcrumb a { color: var(--learn-muted); text-decoration: none; }
.learn-breadcrumb .sep { padding: 0 6px; }

.index-hero { padding: 20px 0 8px; border-bottom: 1px solid var(--learn-line); margin-bottom: 20px; }
.kicker {
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--learn-muted);
}
.index-hero h1 { font-size: clamp(26px, 4vw, 38px); line-height: 1.25; margin: 8px 0 6px; }
.index-hero h1 .code { font-size: 0.55em; color: var(--learn-muted); letter-spacing: 0.06em; }
.lede { font-size: 17px; color: var(--learn-ink-2); margin: 6px 0; max-width: 62ch; }
.meta { display: flex; gap: 8px; flex-wrap: wrap; margin: 12px 0 4px; }
.meta span {
  font-size: 12px;
  color: var(--learn-ink-2);
  border: 1px solid var(--learn-line);
  border-radius: 999px;
  padding: 2px 10px;
}

.learn-card {
  background: var(--learn-surface);
  border: 1px solid var(--learn-line);
  border-radius: 14px;
  padding: 18px 20px;
  margin: 16px 0;
}
.learn-card h2 { font-size: 17px; margin: 0 0 8px; letter-spacing: 0.02em; }
.learn-card p { margin: 0; color: var(--learn-ink-2); }
.learn-caution { border-color: var(--learn-caution); }
.learn-caution h2 { color: var(--learn-caution); }

.learn-figure { text-align: center; }
.learn-svg { width: 180px; max-width: 60vw; height: auto; }

.learn-links { margin: 0; padding-left: 18px; }
.learn-links li { margin: 4px 0; color: var(--learn-ink-2); }
.learn-columns { columns: 2 220px; column-gap: 28px; }
.learn-group { margin: 18px 0; }
.learn-group h3 { font-size: 15px; margin: 0 0 6px; }

.learn-table-wrap { overflow-x: auto; }
.learn-table { width: 100%; border-collapse: collapse; font-size: 14px; }
.learn-table th, .learn-table td {
  text-align: left;
  padding: 8px 10px;
  border-bottom: 1px solid var(--learn-line);
  vertical-align: top;
}
.learn-table th { color: var(--learn-muted); font-weight: 600; white-space: nowrap; }
.learn-table td { color: var(--learn-ink-2); }

.learn-cta {
  margin: 26px 0 8px;
  padding: 20px;
  border: 1px solid var(--learn-line);
  border-radius: 14px;
  background: var(--learn-surface);
  display: flex;
  gap: 16px;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
}
.learn-cta p { margin: 0; color: var(--learn-ink-2); }
.btn {
  display: inline-block;
  background: var(--learn-ink);
  color: var(--learn-bg);
  text-decoration: none;
  border-radius: 999px;
  padding: 9px 18px;
  font-size: 14px;
  white-space: nowrap;
}

.learn-footer {
  border-top: 1px solid var(--learn-line);
  margin-top: 32px;
  padding-top: 18px;
  font-size: 13px;
  color: var(--learn-ink-2);
}
.learn-license p { margin: 6px 0; }
.learn-footer-links { display: flex; gap: 14px; flex-wrap: wrap; margin: 12px 0 4px; }
.muted { color: var(--learn-muted); }

@media (max-width: 560px) {
  .learn-cta { align-items: flex-start; }
  .learn-card { padding: 16px; }
}