/* ParetoGTICal handbook — plain CSS, no frameworks. Light/dark via prefers-color-scheme + manual toggle. */
:root {
  --bg: #ffffff;
  --bg-soft: #f6f8fa;
  --fg: #1a1c1f;
  --fg-soft: #57606a;
  --accent: #0b62c4;
  --accent-soft: #e7f0fb;
  --line: #d8dee4;
  --k-blue: #1f77b4;
  --b-red: #d62728;
  --front-green: #2ca02c;
  --warn: #b45309;
  --pass: #1a7f37;
  --fail: #c62828;
  --card: #ffffff;
  --shadow: 0 1px 3px rgba(0,0,0,.08);
}
html[data-theme="dark"] {
  --bg: #0e1116;
  --bg-soft: #161b22;
  --fg: #e6e8eb;
  --fg-soft: #9aa4af;
  --accent: #4f9cf9;
  --accent-soft: #12233a;
  --line: #2a313a;
  --k-blue: #5aa9e6;
  --b-red: #e57373;
  --front-green: #66bb6a;
  --warn: #e3a008;
  --pass: #4caf50;
  --fail: #ef5350;
  --card: #161b22;
  --shadow: 0 1px 3px rgba(0,0,0,.4);
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, "Noto Sans", "Source Han Sans SC", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Droid Sans Fallback", sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.75;
  font-size: 16px;
}
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
code, pre, .mono {
  font-family: ui-monospace, "SF Mono", Menlo, Consolas, "DejaVu Sans Mono", monospace;
  font-size: 0.88em;
}
code { background: var(--bg-soft); border: 1px solid var(--line); border-radius: 4px; padding: 0.08em 0.35em; }
pre {
  background: var(--bg-soft); border: 1px solid var(--line); border-radius: 8px;
  padding: 12px 14px; overflow-x: auto; line-height: 1.5;
}
pre code { background: none; border: none; padding: 0; }
img, svg { max-width: 100%; height: auto; }
figure { margin: 18px 0; }
figure img { width: 100%; border: 1px solid var(--line); border-radius: 8px; }
figcaption, .src {
  font-size: 13px; color: var(--fg-soft); margin-top: 6px; line-height: 1.55;
}
figcaption .src { display: block; margin-top: 2px; }

/* handbook bilingual switch (skill 0.5.0).  Paste into the site's stylesheet unchanged.
   Without JavaScript nothing sets data-lang, so Chinese shows. */
html[data-lang="en"] .l-zh,
html:not([data-lang="en"]) .l-en { display: none !important; }

.lang-toggle {
  font: inherit; font-size: 0.9rem; padding: 0.3rem 0.8rem; min-height: 44px; min-width: 44px;
  border: 1px solid currentColor; border-radius: 999px; background: transparent; color: inherit; cursor: pointer;
}
.lang-toggle:focus-visible { outline: 2px solid currentColor; outline-offset: 2px; }

/* ---------- layout ---------- */
.wrap { max-width: 1080px; margin: 0 auto; padding: 16px 16px 64px; }
.topbar {
  position: sticky; top: 0; z-index: 50; background: var(--bg);
  border-bottom: 1px solid var(--line);
  display: flex; align-items: center; gap: 12px; padding: 8px 16px;
}
.topbar .brand { font-weight: 700; font-size: 15px; white-space: nowrap; }
.topbar .spacer { margin-left: auto; }
.topbar nav { display: flex; gap: 4px; flex-wrap: wrap; font-size: 14px; }
.topbar nav a { padding: 4px 8px; border-radius: 6px; color: var(--fg-soft); }
.topbar nav a.cur { background: var(--accent-soft); color: var(--accent); font-weight: 600; }
#themeBtn {
  border: 1px solid var(--line); background: var(--bg-soft);
  color: var(--fg); border-radius: 8px; padding: 4px 10px; cursor: pointer; font-size: 14px;
}
.topbar .lang-toggle { margin-left: 6px; }
.toc {
  background: var(--bg-soft); border: 1px solid var(--line); border-radius: 10px;
  padding: 12px 16px; margin: 16px 0 26px; font-size: 14px;
}
.toc b { display: block; margin-bottom: 6px; }
.toc ol { margin: 0; padding-left: 22px; }
.toc li { margin: 2px 0; }
.toc.toc-compact { padding: 6px 14px; margin: 10px 0 14px; line-height: 1.9; }
.toc.toc-compact a { white-space: nowrap; }
h1 { font-size: 26px; margin: 18px 0 8px; line-height: 1.35; }
h2 { font-size: 20px; margin: 34px 0 10px; padding-top: 10px; border-top: 1px solid var(--line); }
h2:first-of-type { border-top: none; padding-top: 0; }
h3 { font-size: 17px; margin: 24px 0 8px; }
p { margin: 10px 0; }
.lead { font-size: 17px; color: var(--fg); margin: 6px 0 14px; }
.note {
  border-left: 4px solid var(--accent); background: var(--accent-soft);
  border-radius: 0 8px 8px 0; padding: 10px 14px; margin: 14px 0; font-size: 15px;
}
.note.warn { border-left-color: var(--warn); background: rgba(251,191,36,.10); }
.note.pending { border-left-color: var(--fg-soft); background: var(--bg-soft); }
.note b { display: block; margin-bottom: 2px; }

/* ---------- tables ---------- */
.tblwrap { overflow-x: auto; margin: 14px 0; border: 1px solid var(--line); border-radius: 10px; }
table { border-collapse: collapse; width: 100%; font-size: 14px; min-width: 620px; }
th, td { padding: 8px 10px; border-bottom: 1px solid var(--line); text-align: left; vertical-align: top; }
th { background: var(--bg-soft); font-weight: 600; white-space: nowrap; }
tr:last-child td { border-bottom: none; }
td.num, th.num { text-align: right; font-variant-numeric: tabular-nums; white-space: nowrap; }
.tag { display: inline-block; padding: 1px 8px; border-radius: 999px; font-size: 12.5px; font-weight: 600; white-space: nowrap; }
.tag.pass { background: rgba(26,127,55,.14); color: var(--pass); }
.tag.fail { background: rgba(198,40,40,.12); color: var(--fail); }
.tag.pending { background: var(--bg-soft); color: var(--fg-soft); border: 1px solid var(--line); }
.tag.part { background: rgba(251,191,36,.16); color: var(--warn); }
.arrow-up { color: var(--pass); } .arrow-flat { color: var(--fg-soft); } .arrow-down { color: var(--fail); }

/* ---------- cards / home ---------- */
.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: 12px;
  padding: 14px 16px; box-shadow: var(--shadow); margin: 0;
}
.card h3 { margin: 0 0 8px; font-size: 16px; }
.card p { margin: 6px 0; font-size: 14.5px; }
.kv { font-size: 13.5px; color: var(--fg-soft); }
.hero {
  border: 1px solid var(--line); border-left: 5px solid var(--accent);
  border-radius: 10px; background: var(--accent-soft); padding: 14px 18px; margin: 14px 0 20px;
}
.hero p { margin: 4px 0; font-size: 16px; }
.qa { display:grid; grid-template-columns: auto 1fr; gap: 4px 10px; font-size: 14.5px; margin: 8px 0; }
.qa dt { font-weight: 700; color: var(--accent); white-space: nowrap; }
.qa dd { margin: 0; }

/* skeleton diagram */
.skel { width: 100%; height: auto; display: block; margin: 8px 0; }

/* animations */
.anim {
  border: 1px solid var(--line); border-radius: 12px; background: var(--card);
  padding: 14px; margin: 16px 0;
}
.anim h3 { margin: 0 0 4px; }
.anim .hint { font-size: 13.5px; color: var(--fg-soft); margin: 2px 0 10px; }
.anim .ctl { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; font-size: 14px; margin: 8px 0; }
.anim .ctl label { font-variant-numeric: tabular-nums; }
.anim svg { width: 100%; height: auto; display: block; }
.anim .readout { font-size: 14px; font-variant-numeric: tabular-nums; }
.anim .readout b { color: var(--accent); }
button.act {
  border: 1px solid var(--line); background: var(--bg-soft); color: var(--fg);
  border-radius: 8px; padding: 5px 12px; cursor: pointer; font-size: 14px;
}
button.act:hover { border-color: var(--accent); color: var(--accent); }
input[type=range] { accent-color: var(--accent); width: 180px; }

footer { margin-top: 48px; padding-top: 14px; border-top: 1px solid var(--line); font-size: 13px; color: var(--fg-soft); }

/* phone */
@media (max-width: 720px) {
  body { font-size: 15.5px; }
  .wrap { padding: 12px 16px 48px; }
  .grid2 { grid-template-columns: 1fr; }
  .topbar { flex-wrap: wrap; }
  .topbar nav { order: 3; width: 100%; overflow-x: auto; flex-wrap: nowrap; padding-bottom: 2px; }
  .topbar .spacer { order: 2; margin-left: auto; }
  h1 { font-size: 22px; }
  table { min-width: 480px; }
  .anim .ctl input[type=range] { width: 130px; }
}
@media print {
  .topbar, .anim .ctl, #themeBtn { display: none; }
}