:root {
  --ink: #1c1917;
  --muted: #57534e;
  --line: #d6d3d1;
  --soft: #f5f5f4;
  --paper: #fafaf9;
  --brand: #4d7c0f;
  --brand-deep: #365314;
  --accent: #65a30d;
  --olive-wash: #ecfccb;
  --tile: #ffffff;
  --max: 1100px;
  --toc-w: 200px;
  --radius: 6px;
  --shadow: 0 4px 18px rgba(28, 25, 23, 0.06);
  font-family: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background:
    linear-gradient(180deg, #fafaf9 0%, #f5f5f4 40%, #e7e5e4 100%);
  line-height: 1.8;
  min-height: 100vh;
}

a { color: var(--brand-deep); text-underline-offset: 3px; }
a:hover { color: var(--accent); }
img { max-width: 100%; height: auto; display: block; }
.wrap { width: min(100% - 2rem, var(--max)); margin-inline: auto; }

.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(250, 250, 249, 0.95);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(8px);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.6rem 0;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  color: var(--ink);
  text-decoration: none;
  font-weight: 700;
}
.brand img { width: 36px; height: 36px; border-radius: 6px; object-fit: cover; }

.nav-desktop { display: flex; gap: 1rem; flex-wrap: wrap; }
.nav-desktop a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.92rem;
}
.nav-desktop a:hover { color: var(--brand); }

.menu-toggle {
  display: none;
  border: 1px solid var(--line);
  background: var(--tile);
  color: var(--ink);
  border-radius: 6px;
  padding: 0.4rem 0.75rem;
  cursor: pointer;
  font-size: 0.9rem;
}

#mobile-nav {
  display: none;
  flex-direction: column;
  gap: 0.35rem;
  padding: 0.5rem 1rem 1rem;
  border-top: 1px solid var(--line);
  background: var(--soft);
}
#mobile-nav.open { display: flex; }
#mobile-nav a {
  color: var(--ink);
  text-decoration: none;
  padding: 0.45rem 0.2rem;
}

.folio-eyebrow {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem 0.6rem;
  align-items: center;
  padding: 0.85rem 0 0.25rem;
  font-size: 0.82rem;
  color: var(--muted);
  letter-spacing: 0.02em;
  border-bottom: 1px solid var(--line);
  margin-bottom: 1.25rem;
}
.folio-eyebrow .crumb-sep { color: var(--line); }
.folio-eyebrow strong { color: var(--brand-deep); font-weight: 600; }

.folio-shell {
  display: grid;
  grid-template-columns: var(--toc-w) minmax(0, 1fr);
  gap: 2rem;
  align-items: start;
  padding-bottom: 3rem;
}

.folio-toc {
  position: sticky;
  top: 4.2rem;
  padding: 0.85rem 0.75rem;
  background: var(--tile);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}
.folio-toc h2 {
  margin: 0 0 0.65rem;
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 700;
}
.folio-toc a {
  display: block;
  padding: 0.35rem 0.4rem;
  margin-bottom: 0.15rem;
  color: var(--ink);
  text-decoration: none;
  font-size: 0.88rem;
  border-left: 2px solid transparent;
}
.folio-toc a:hover {
  border-left-color: var(--accent);
  background: var(--olive-wash);
  color: var(--brand-deep);
}

.folio-reader {
  background: var(--tile);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 1.75rem 1.6rem 2rem;
  box-shadow: var(--shadow);
}
.folio-reader h1 {
  margin: 0 0 0.85rem;
  font-size: clamp(1.35rem, 2.8vw, 1.75rem);
  line-height: 1.35;
  color: var(--ink);
  font-weight: 700;
}
.folio-reader .deck {
  margin: 0 0 1.25rem;
  color: var(--muted);
  font-size: 1.02rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--line);
}
.folio-reader h2 {
  margin: 1.6rem 0 0.55rem;
  font-size: 1.18rem;
  color: var(--brand-deep);
  padding-top: 0.35rem;
}
.folio-reader h3 {
  margin: 1.2rem 0 0.45rem;
  font-size: 1.05rem;
}
.folio-reader p { margin: 0 0 0.9rem; }
.folio-reader ul { margin: 0 0 1rem; padding-left: 1.2rem; }
.folio-reader li { margin-bottom: 0.35rem; }

.folio-figure {
  margin: 1.1rem 0 1.35rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--soft);
}
.folio-figure img {
  width: 100%;
  aspect-ratio: 16/10;
  object-fit: cover;
}
.folio-figure figcaption {
  padding: 0.55rem 0.85rem;
  font-size: 0.86rem;
  color: var(--muted);
  border-top: 1px solid var(--line);
}

.peer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem 1rem;
  align-items: center;
  margin: 1.25rem 0;
  padding: 0.8rem 1rem;
  background: var(--olive-wash);
  border: 1px solid #d9f99d;
  border-radius: var(--radius);
}
.peer-links a {
  color: var(--brand-deep);
  font-weight: 600;
  text-decoration: none;
}
.peer-links a:hover { text-decoration: underline; }

.faq details {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 0.6rem 0.85rem;
  margin-bottom: 0.5rem;
  background: var(--soft);
}
.faq summary { cursor: pointer; font-weight: 600; }
.faq details p { margin: 0.5rem 0 0.1rem; color: var(--muted); }

.site-footer {
  border-top: 1px solid var(--line);
  background: #1c1917;
  color: #d6d3d1;
  padding: 1.35rem 0;
}
.site-footer a { color: #bef264; text-decoration: none; }
.site-footer a:hover { text-decoration: underline; }
.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.1rem;
  margin-bottom: 0.6rem;
}
.site-footer p { margin: 0; font-size: 0.9rem; color: #a8a29e; }

.page-hero { padding: 1.6rem 0 0.4rem; }
.page-hero h1 { margin: 0 0 0.35rem; font-size: 1.5rem; }
.muted { color: var(--muted); }
.prose { padding-bottom: 2rem; }
.prose h2 { margin: 1.3rem 0 0.5rem; font-size: 1.12rem; color: var(--brand-deep); }
.prose p { margin: 0 0 0.85rem; }

.err-box { text-align: center; padding: 3.5rem 0 4rem; }
.err-box h1 { margin: 0 0 0.75rem; }
.btn {
  display: inline-block;
  padding: 0.55rem 1.1rem;
  border-radius: 6px;
  text-decoration: none;
  font-weight: 600;
}
.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-deep); color: #fff; }

@media (max-width: 900px) {
  .nav-desktop { display: none; }
  .menu-toggle { display: inline-block; }
  .folio-shell { grid-template-columns: 1fr; gap: 1rem; }
  .folio-toc {
    position: static;
    display: flex;
    flex-wrap: wrap;
    gap: 0.25rem 0.5rem;
    align-items: center;
  }
  .folio-toc h2 { width: 100%; margin-bottom: 0.35rem; }
  .folio-toc a {
    border-left: none;
    border-bottom: 2px solid transparent;
    padding: 0.3rem 0.45rem;
  }
  .folio-toc a:hover { border-bottom-color: var(--accent); }
  .folio-reader { padding: 1.25rem 1rem 1.5rem; }
}

/* SEO keyword highlight */
strong.kw, .kw{color:var(--accent,var(--brand,#c43b2c));font-weight:700}
mark.kw{background:rgba(196,59,44,.12);color:inherit;padding:0 .15em;border-radius:3px}