:root {
  color-scheme: light;
  --bg: #f7f2ea;
  --paper: #fffaf2;
  --text: #29231d;
  --muted: #776b5f;
  --line: #eadfce;
  --accent: #9b4f23;
  --accent-weak: #f0dac7;
  --shadow: 0 18px 60px rgba(74, 49, 27, 0.12);
  --reader-font-size: 19px;
}

html.dark {
  color-scheme: dark;
  --bg: #171512;
  --paper: #221f1a;
  --text: #eee3d2;
  --muted: #b4a58f;
  --line: #3a332b;
  --accent: #e3a36f;
  --accent-weak: #3a2a20;
  --shadow: 0 18px 60px rgba(0, 0, 0, 0.35);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: radial-gradient(circle at top left, var(--accent-weak), transparent 30rem), var(--bg);
  color: var(--text);
  font-family: ui-serif, "Songti SC", "Noto Serif CJK SC", "Source Han Serif SC", Georgia, serif;
}

.progress {
  position: fixed;
  inset: 0 auto auto 0;
  z-index: 20;
  height: 4px;
  width: 0;
  background: var(--accent);
}

.hero { padding: 80px 24px 52px; }
.hero-inner { max-width: 980px; margin: 0 auto; }
.eyebrow {
  color: var(--accent);
  font: 700 13px/1.6 ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  letter-spacing: .12em;
  text-transform: uppercase;
}
h1 {
  margin: 10px 0 18px;
  font-size: clamp(48px, 9vw, 112px);
  line-height: .95;
  letter-spacing: -0.06em;
}
.subtitle {
  max-width: 760px;
  color: var(--muted);
  font-size: clamp(18px, 2vw, 24px);
  line-height: 1.8;
}
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 30px; }
.button, .toolbar button {
  border: 1px solid var(--line);
  background: color-mix(in srgb, var(--paper) 86%, transparent);
  color: var(--text);
  border-radius: 999px;
  padding: 10px 16px;
  text-decoration: none;
  font: 600 14px/1 ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
  cursor: pointer;
}
.button.primary { border-color: var(--accent); background: var(--accent); color: #fffaf2; }

.toolbar {
  position: sticky;
  top: 12px;
  z-index: 15;
  display: flex;
  justify-content: center;
  gap: 8px;
  margin: 0 auto 20px;
  padding: 0 16px;
  pointer-events: none;
}
.toolbar button { box-shadow: 0 8px 28px rgba(0,0,0,.08); backdrop-filter: blur(12px); pointer-events: auto; }

.layout {
  display: grid;
  grid-template-columns: minmax(220px, 300px) minmax(0, 860px);
  gap: 30px;
  align-items: start;
  max-width: 1230px;
  margin: 0 auto;
  padding: 0 24px 96px;
}
.toc {
  position: sticky;
  top: 70px;
  max-height: calc(100vh - 92px);
  overflow: auto;
  border: 1px solid var(--line);
  border-radius: 24px;
  background: color-mix(in srgb, var(--paper) 88%, transparent);
  box-shadow: var(--shadow);
  backdrop-filter: blur(14px);
}
.toc-head {
  position: sticky;
  top: 0;
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 18px 18px 12px;
  background: color-mix(in srgb, var(--paper) 96%, transparent);
  color: var(--muted);
  font: 700 13px/1.5 ui-sans-serif, system-ui, sans-serif;
}
.toc nav { padding: 0 10px 14px; }
.toc-link {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 10px;
  align-items: baseline;
  padding: 8px 10px;
  border-radius: 12px;
  color: var(--muted);
  text-decoration: none;
  font-size: 14px;
  line-height: 1.45;
}
.toc-link.major { margin-top: 6px; color: var(--text); font-weight: 700; }
.toc-link.minor { padding-left: 20px; }
.toc-link small { color: var(--muted); font-family: ui-sans-serif, system-ui, sans-serif; }
.toc-link.active, .toc-link:hover { background: var(--accent-weak); color: var(--accent); }

.reader {
  min-width: 0;
  border: 1px solid var(--line);
  border-radius: 32px;
  background: var(--paper);
  box-shadow: var(--shadow);
  padding: clamp(26px, 5vw, 72px);
}
.article-section { margin: 0 0 42px; }
h2, h3 { scroll-margin-top: 92px; font-family: ui-serif, "Songti SC", "Noto Serif CJK SC", Georgia, serif; }
h2 {
  margin: 1.5em 0 .8em;
  padding-top: .5em;
  border-top: 1px solid var(--line);
  font-size: clamp(30px, 4vw, 48px);
  line-height: 1.18;
  letter-spacing: -0.04em;
}
.article-section:first-child h2 { margin-top: 0; border-top: 0; }
h3 { margin: 2em 0 .7em; color: var(--accent); font-size: clamp(22px, 2.4vw, 30px); line-height: 1.35; }
p, li { font-size: var(--reader-font-size); line-height: 2.05; letter-spacing: .02em; }
p { margin: 0 0 1.05em; text-align: justify; text-justify: inter-ideograph; }
ul { margin: 0 0 1.2em 1.4em; padding: 0; }
.page-marker {
  display: inline-flex;
  margin: 22px 0 12px;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 4px 10px;
  color: var(--muted);
  font: 700 12px/1.4 ui-sans-serif, system-ui, sans-serif;
}
.backtop {
  position: fixed;
  right: 22px;
  bottom: 22px;
  width: 44px;
  height: 44px;
  border: 1px solid var(--line);
  border-radius: 50%;
  background: var(--paper);
  color: var(--accent);
  box-shadow: var(--shadow);
  cursor: pointer;
  opacity: 0;
  transform: translateY(10px);
  transition: .2s ease;
}
.backtop.show { opacity: 1; transform: translateY(0); }

@media (max-width: 900px) {
  .layout { display: block; padding-inline: 14px; }
  .toc {
    display: none;
    position: fixed;
    inset: 74px 14px auto;
    z-index: 30;
    max-height: 70vh;
  }
  .toc.open { display: block; }
  .reader { border-radius: 24px; }
  .toolbar { justify-content: flex-start; overflow-x: auto; }
}

@media print {
  .toolbar, .toc, .backtop, .progress, .hero-actions { display: none; }
  body { background: #fff; }
  .layout { display: block; max-width: none; padding: 0; }
  .reader { border: 0; box-shadow: none; padding: 0; }
}

.pdf-figure {
  margin: 18px auto 28px;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background: color-mix(in srgb, var(--bg) 54%, var(--paper));
}
.pdf-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-height: 76vh;
  object-fit: contain;
  border-radius: 12px;
}
.pdf-figure figcaption {
  margin-top: 10px;
  color: var(--muted);
  text-align: center;
  font: 600 12px/1.5 ui-sans-serif, system-ui, sans-serif;
}

blockquote {
  margin: 1.2em 0 1.35em;
  padding: 18px 22px 18px 24px;
  border-left: 4px solid var(--accent);
  border-radius: 0 18px 18px 0;
  background: color-mix(in srgb, var(--accent-weak) 64%, transparent);
  color: color-mix(in srgb, var(--text) 88%, var(--accent));
  font-size: calc(var(--reader-font-size) + 1px);
  line-height: 2;
  letter-spacing: .025em;
}

.reader ol,
.reader ul {
  margin: 0 0 1.2em 1.65em;
  padding-left: 1.2em;
}
.reader li {
  margin: .42em 0;
  padding-left: .2em;
}
.reader ol ol,
.reader ul ul,
.reader ol ul,
.reader ul ol {
  margin-top: .55em;
  margin-bottom: .65em;
}
.outline-list > li {
  margin-bottom: .9em;
}

.pdf-figure img {
  cursor: zoom-in;
}
.no-scroll {
  overflow: hidden;
}
.image-lightbox {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 28px;
  background: rgba(18, 14, 10, .84);
  backdrop-filter: blur(10px);
  cursor: zoom-out;
}
.image-lightbox.open {
  display: flex;
}
.image-lightbox img {
  max-width: min(96vw, 1280px);
  max-height: 92vh;
  width: auto;
  height: auto;
  object-fit: contain;
  border-radius: 14px;
  box-shadow: 0 28px 80px rgba(0, 0, 0, .45);
}
.lightbox-close {
  position: fixed;
  top: 18px;
  right: 20px;
  width: 44px;
  height: 44px;
  border: 1px solid rgba(255, 255, 255, .28);
  border-radius: 50%;
  background: rgba(0, 0, 0, .38);
  color: #fff;
  font-size: 30px;
  line-height: 1;
  cursor: pointer;
}