/* tangkas1.live — folio template: warm ink on paper (not tangxin888 palette) */
:root {
  --paper: #efe6d5;
  --paper-deep: #e4d8c2;
  --ink: #2b2118;
  --ink-soft: #4a3b2f;
  --muted: #7a6a58;
  --line: #c9b89a;
  --accent: #6e3b2e;
  --accent-soft: #8f5a3c;
  --rule: #b59a72;
  --soft: #f7f1e4;
  --max: 1120px;
  --toc-w: 168px;
  --reader-gap: 1.75rem;
}

*,
*::before,
*::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: "Source Han Serif SC", "Noto Serif SC", "Songti SC", "SimSun", Georgia, serif;
  color: var(--ink);
  background:
    radial-gradient(ellipse at 12% 0%, rgba(181, 154, 114, 0.18), transparent 42%),
    linear-gradient(180deg, var(--paper) 0%, var(--paper-deep) 100%);
  min-height: 100vh;
  line-height: 1.75;
  font-size: 16px;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent); text-decoration: none; border-bottom: 1px solid transparent; }
a:hover { color: var(--accent-soft); border-bottom-color: var(--rule); }

.skip {
  position: absolute; left: -999px; top: 0;
  background: var(--ink); color: var(--paper); padding: .5rem .75rem; z-index: 100;
}
.skip:focus { left: .5rem; top: .5rem; }

/* —— thin masthead —— */
.folio-masthead {
  border-bottom: 1px solid var(--line);
  background: rgba(247, 241, 228, 0.92);
  font-size: .78rem;
  letter-spacing: .04em;
}
.folio-masthead-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: .35rem 1rem;
  display: flex;
  flex-wrap: wrap;
  gap: .35rem .75rem;
  align-items: baseline;
  color: var(--muted);
}
.folio-masthead .domain {
  font-family: "Segoe UI", "PingFang SC", sans-serif;
  color: var(--ink-soft);
  font-weight: 600;
  letter-spacing: .02em;
}
.folio-crumb { display: flex; flex-wrap: wrap; gap: .35rem; align-items: baseline; }
.folio-crumb span[aria-hidden="true"] { color: var(--rule); }

/* —— nav row —— */
.folio-bar {
  border-bottom: 1px solid var(--line);
  background: var(--soft);
  position: sticky;
  top: 0;
  z-index: 40;
}
.folio-bar-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: .55rem 1rem;
  display: flex;
  align-items: center;
  gap: .75rem;
}
.brand {
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  color: var(--ink);
  border: 0;
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: .06em;
}
.brand img {
  width: 34px; height: 34px;
  border-radius: 6px;
  border: 1px solid var(--line);
}
.brand:hover { border-bottom: 0; color: var(--accent); }

.menu-toggle {
  margin-left: auto;
  display: none;
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--ink);
  padding: .4rem .7rem;
  font: inherit;
  font-size: .88rem;
  cursor: pointer;
  border-radius: 4px;
}
.menu-toggle:hover { border-color: var(--accent); }

.nav-links {
  margin-left: auto;
  display: flex;
  flex-wrap: wrap;
  gap: .15rem 1.1rem;
  font-family: "Segoe UI", "PingFang SC", sans-serif;
  font-size: .9rem;
}
.nav-links a {
  color: var(--ink-soft);
  border: 0;
  padding: .15rem 0;
}
.nav-links a:hover { color: var(--accent); }

.ads-slot { max-width: var(--max); margin: 0 auto; }

/* —— folio shell: narrow toc + reader —— */
.folio-shell {
  max-width: var(--max);
  margin: 0 auto;
  padding: 1.25rem 1rem 3rem;
  display: grid;
  grid-template-columns: var(--toc-w) minmax(0, 1fr);
  gap: 1.5rem 1.75rem;
  align-items: start;
}

.folio-toc {
  position: sticky;
  top: 3.4rem;
  padding: .85rem .7rem;
  border-right: 1px solid var(--line);
  font-family: "Segoe UI", "PingFang SC", sans-serif;
  font-size: .82rem;
  line-height: 1.45;
}
.folio-toc h2 {
  margin: 0 0 .65rem;
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--muted);
  font-family: inherit;
}
.folio-toc ol {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: toc;
}
.folio-toc li { margin: 0 0 .55rem; }
.folio-toc a {
  display: block;
  color: var(--ink-soft);
  border: 0;
  padding-left: .15rem;
  border-left: 2px solid transparent;
}
.folio-toc a:hover,
.folio-toc a:focus {
  color: var(--accent);
  border-left-color: var(--accent);
}

.folio-reader {
  min-width: 0;
  background: rgba(247, 241, 228, 0.55);
  border: 1px solid var(--line);
  padding: 1.35rem 1.4rem 2rem;
  box-shadow: 0 1px 0 rgba(43, 33, 24, 0.04);
}

.folio-reader > h1 {
  margin: 0 0 .85rem;
  font-size: clamp(1.45rem, 2.4vw, 1.85rem);
  line-height: 1.35;
  letter-spacing: .04em;
  font-weight: 700;
  color: var(--ink);
  border-bottom: 2px solid var(--rule);
  padding-bottom: .65rem;
}

.lede {
  font-size: 1.05rem;
  color: var(--ink-soft);
  margin: 0 0 1.25rem;
  max-width: 48em;
}

.folio-columns {
  column-count: 2;
  column-gap: var(--reader-gap);
  column-rule: 1px solid var(--line);
}

.folio-columns > * {
  break-inside: avoid;
  margin-top: 0;
}

.folio-section {
  margin-bottom: 1.35rem;
}
.folio-section h2 {
  margin: 0 0 .55rem;
  font-size: 1.12rem;
  letter-spacing: .06em;
  color: var(--ink);
  border-bottom: 1px dashed var(--line);
  padding-bottom: .35rem;
  break-after: avoid;
}
.folio-section h3 {
  margin: .85rem 0 .4rem;
  font-size: 1rem;
  color: var(--ink-soft);
}
.folio-section p {
  margin: 0 0 .75rem;
  text-align: justify;
  hyphens: auto;
}
.folio-section ul {
  margin: 0 0 .85rem;
  padding-left: 1.2rem;
}
.folio-section li { margin-bottom: .35rem; }

.folio-figure {
  margin: 0 0 1rem;
  break-inside: avoid;
}
.folio-figure img {
  width: 100%;
  border: 1px solid var(--line);
  background: var(--soft);
}
.folio-figure figcaption {
  margin-top: .4rem;
  font-size: .82rem;
  color: var(--muted);
  font-family: "Segoe UI", "PingFang SC", sans-serif;
  line-height: 1.45;
}

.folio-links {
  margin: 1.25rem 0 0;
  padding: 1rem;
  border: 1px solid var(--line);
  background: var(--soft);
  column-span: all;
}
.folio-links h2 {
  margin: 0 0 .5rem;
  font-size: 1rem;
  border: 0;
}
.folio-links p { margin: 0 0 .5rem; }
.folio-links .ext {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem .9rem;
  font-family: "Segoe UI", "PingFang SC", sans-serif;
  font-size: .92rem;
}

.folio-faq details {
  border-bottom: 1px solid var(--line);
  padding: .55rem 0;
  break-inside: avoid;
}
.folio-faq summary {
  cursor: pointer;
  font-weight: 600;
  color: var(--ink-soft);
}
.folio-faq p { margin: .45rem 0 0; }

.page-simple .folio-shell {
  grid-template-columns: 1fr;
}
.page-simple .folio-toc { display: none; }
.page-simple .folio-reader {
  max-width: 720px;
  margin: 0 auto;
}
.page-simple .folio-columns { column-count: 1; }

.err-box {
  text-align: center;
  padding: 2rem 1rem 1rem;
}
.err-box .code {
  font-size: 3rem;
  letter-spacing: .12em;
  color: var(--accent);
  font-weight: 700;
  line-height: 1;
  margin-bottom: .5rem;
}

.site-footer {
  border-top: 1px solid var(--line);
  background: rgba(228, 216, 194, 0.65);
  font-family: "Segoe UI", "PingFang SC", sans-serif;
  font-size: .86rem;
  color: var(--muted);
}
.footer-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 1.25rem 1rem 1.75rem;
  display: flex;
  flex-wrap: wrap;
  gap: .75rem 1.5rem;
  justify-content: space-between;
  align-items: baseline;
}
.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem 1rem;
}
.footer-nav a { color: var(--ink-soft); border: 0; }
.footer-nav a:hover { color: var(--accent); }

@media (max-width: 900px) {
  .folio-shell {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
  .folio-toc {
    position: static;
    border-right: 0;
    border-bottom: 1px solid var(--line);
    padding: .75rem 0;
    display: flex;
    flex-wrap: wrap;
    gap: .5rem 1rem;
    align-items: baseline;
  }
  .folio-toc h2 { margin: 0; width: 100%; }
  .folio-toc ol {
    display: flex;
    flex-wrap: wrap;
    gap: .35rem .75rem;
  }
  .folio-toc li { margin: 0; }
  .folio-toc a { border-left: 0; border-bottom: 1px solid transparent; padding-left: 0; }
  .folio-toc a:hover { border-left: 0; border-bottom-color: var(--accent); }
  .folio-columns { column-count: 1; }
  .folio-reader { padding: 1.1rem 1rem 1.5rem; }
}

@media (max-width: 720px) {
  .menu-toggle { display: inline-block; }
  .nav-links {
    display: none;
    width: 100%;
    flex-direction: column;
    gap: 0;
    margin: 0;
    padding: .35rem 0 .15rem;
    border-top: 1px solid var(--line);
  }
  .nav-links.open { display: flex; }
  .nav-links a {
    padding: .55rem 0;
    border-bottom: 1px solid var(--line);
  }
  .folio-bar-inner { flex-wrap: wrap; }
}