/* ---------------------------------------------------------------
   Shared stylesheet — 笔记 / Notes
   No external fonts, no build step, works from any subpath.
   --------------------------------------------------------------- */

:root {
  --bg: #fbfaf7;
  --fg: #16181d;
  --muted: #616775;
  --line: #e4e1d8;
  --card: #ffffff;
  --accent: #b22222;
  --navy: #1f3864;
  --th-bg: #1f3864;
  --th-fg: #ffffff;
  --good: #1a7f37;
  --max: 1000px;
  --radius: 14px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #101218;
    --fg: #e9eaef;
    --muted: #9aa1b0;
    --line: #272c36;
    --card: #171a21;
    --accent: #e0635f;
    --navy: #7ea0d8;
    --th-bg: #2b3650;
    --th-fg: #e9eaef;
    --good: #4fb96f;
  }
}

* { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei",
    "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", sans-serif;
  font-size: 16px;
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }

.wrap {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 22px;
}

/* ---------- site header ---------- */
.site-head {
  border-bottom: 1px solid var(--line);
  background: var(--bg);
}
.site-head .wrap {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding-top: 20px;
  padding-bottom: 18px;
  flex-wrap: wrap;
}
.brand {
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.02em;
  color: var(--fg);
}
.brand:hover { text-decoration: none; }
.brand .dot { color: var(--accent); }
.site-head nav {
  display: flex;
  gap: 18px;
  font-size: 14px;
}
.site-head nav a { color: var(--muted); }
.site-head nav a:hover { color: var(--accent); }

/* ---------- hero ---------- */
.hero {
  padding: 64px 0 40px;
}
.hero h1 {
  margin: 0 0 14px;
  font-size: clamp(30px, 5vw, 44px);
  line-height: 1.2;
  letter-spacing: -0.01em;
}
.hero p {
  margin: 0;
  max-width: 620px;
  color: var(--muted);
  font-size: 17px;
}

/* ---------- cards ---------- */
.cards {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
  padding-bottom: 20px;
}
@media (min-width: 760px) {
  .cards { grid-template-columns: 1fr 1fr; }
}

.card {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 26px 24px 22px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  color: var(--fg);
  transition: transform 0.16s ease, box-shadow 0.16s ease,
    border-color 0.16s ease;
}
.card:hover {
  text-decoration: none;
  transform: translateY(-2px);
  border-color: var(--line);
  box-shadow: 0 12px 32px rgba(20, 24, 34, 0.09);
}
.card .chip {
  align-self: flex-start;
  font-size: 11.5px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  border: 1px solid currentColor;
  border-radius: 999px;
  padding: 2px 10px;
  opacity: 0.9;
}
.card h2 {
  margin: 2px 0 0;
  font-size: 21px;
  line-height: 1.35;
  letter-spacing: -0.005em;
}
.card p {
  margin: 0;
  color: var(--muted);
  font-size: 14.5px;
  line-height: 1.7;
  flex: 1;
}
.card .meta {
  display: flex;
  gap: 12px;
  font-size: 12.5px;
  color: var(--muted);
  border-top: 1px solid var(--line);
  padding-top: 12px;
  margin-top: 4px;
}
.card .go { color: var(--accent); margin-left: auto; }

/* ---------- article ---------- */
.article {
  max-width: 780px;
  margin: 0 auto;
  padding: 52px 0 80px;
}
.article .kicker {
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 14px;
}
.article h1 {
  margin: 0 0 18px;
  font-size: clamp(27px, 4.4vw, 38px);
  line-height: 1.28;
  letter-spacing: -0.01em;
}
.byline {
  color: var(--muted);
  font-size: 13.5px;
  padding-bottom: 26px;
  border-bottom: 1px solid var(--line);
  margin-bottom: 34px;
}
.article h2 {
  font-size: 22px;
  margin: 52px 0 14px;
  padding-top: 4px;
  letter-spacing: -0.005em;
}
.article h2 .num {
  color: var(--accent);
  font-weight: 700;
  margin-right: 8px;
}
.article h3 {
  font-size: 17px;
  margin: 30px 0 8px;
}
.article p { margin: 0 0 16px; }
.article ul {
  margin: 0 0 18px;
  padding-left: 22px;
}
.article li { margin-bottom: 9px; }
.article strong { font-weight: 700; }
.article .neg { color: var(--accent); }
.article .pos { color: var(--good); }

.lead {
  font-size: 16px;
  color: var(--muted);
}

.callout {
  background: rgba(178, 34, 34, 0.055);
  border-left: 3px solid var(--accent);
  border-radius: 0 10px 10px 0;
  padding: 18px 20px;
  margin: 0 0 30px;
  font-size: 15.5px;
  line-height: 1.8;
}
.callout b { color: var(--accent); }

/* ---------- TOC ---------- */
.toc {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 18px 22px;
  margin: 0 0 40px;
  background: var(--card);
}
.toc h2 {
  margin: 0 0 10px !important;
  font-size: 13px !important;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  padding: 0 !important;
}
.toc ol {
  margin: 0;
  padding-left: 20px;
  font-size: 14.5px;
  color: var(--muted);
}
.toc li { margin-bottom: 5px; }
.toc a { color: var(--fg); }

/* ---------- tables ---------- */
.tbl-wrap {
  overflow-x: auto;
  margin: 6px 0 26px;
  border: 1px solid var(--line);
  border-radius: 10px;
}
table {
  width: 100%;
  border-collapse: collapse;
  font-size: 14px;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}
thead th {
  background: var(--th-bg);
  color: var(--th-fg);
  font-weight: 600;
  text-align: right;
  padding: 10px 12px;
  font-size: 13px;
  white-space: nowrap;
}
thead th:first-child { text-align: left; }
tbody td {
  padding: 9px 12px;
  text-align: right;
  border-top: 1px solid var(--line);
}
tbody td:first-child { text-align: left; font-weight: 500; }
tbody tr:nth-child(even):not(.hl) { background: rgba(120, 130, 150, 0.055); }
tbody tr.hl { background: rgba(178, 34, 34, 0.085); }
tbody tr.hl td { font-weight: 600; }
caption {
  caption-side: bottom;
  text-align: left;
  color: var(--muted);
  font-size: 12.5px;
  line-height: 1.7;
  padding: 10px 2px 0;
  white-space: normal;
}

/* ---------- figures ---------- */
figure {
  margin: 34px -8px 34px;
}
@media (min-width: 900px) {
  figure { margin-left: -70px; margin-right: -70px; }
}
figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: #fff;
}
figcaption {
  color: var(--muted);
  font-size: 12.5px;
  line-height: 1.7;
  margin-top: 10px;
  padding: 0 8px;
}

/* ---------- footer ---------- */
.site-foot {
  border-top: 1px solid var(--line);
  margin-top: 40px;
  padding: 26px 0 40px;
  color: var(--muted);
  font-size: 13px;
}
.site-foot .wrap {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

/* ---------- misc ---------- */
.article h2, .article h3 { scroll-margin-top: 20px; }
.article code {
  font-family: ui-monospace, SFMono-Regular, "Cascadia Mono", Consolas, monospace;
  font-size: 0.88em;
  background: rgba(120, 130, 150, 0.14);
  padding: 1px 6px;
  border-radius: 5px;
}
.tags {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-top: 6px;
}
.tag {
  font-size: 12px;
  color: var(--muted);
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 2px 9px;
}

@media print {
  .site-head, .site-foot, .toc { display: none; }
  body { background: #fff; }
  .article { padding: 0; }
  figure { margin-left: 0; margin-right: 0; break-inside: avoid; }
  .tbl-wrap { break-inside: avoid; }
  a { color: #000; }
}