/* ─── Variables ─────────────────────────────────────────────────────── */

:root {
  --paper:  #1c1916;
  --ink:    #f0eae0;
  --body:   #a09790;
  --dim:    #7a6e66;
  --rule:   rgba(240, 234, 224, 0.1);
  --rule-2: #f0eae0;
  --accent: #c4958a;

  --pad-x:  max(56px, 6vw);
  --col-gap: 32px;
}

[data-theme="light"] {
  --paper:  #f2ede5;
  --ink:    #1c1916;
  --body:   #5a5550;
  --dim:    #7a6e66;
  --rule:   rgba(28, 25, 22, 0.1);
  --rule-2: #1c1916;
  --accent: #c4958a;
}

/* ─── Reset ─────────────────────────────────────────────────────────── */

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  background: var(--paper);
  color: var(--ink);
  font-family: 'Inter', -apple-system, 'Helvetica Neue', sans-serif;
  font-size: 14px;
  line-height: 1.55;
  font-weight: 300;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  transition: background 0.2s, color 0.2s;
}

body {
  max-width: 1280px;
  margin: 0 auto;
  padding: 96px var(--pad-x) 160px;
}

/* ─── Theme button ──────────────────────────────────────────────────── */

.theme-btn {
  background: none;
  border: 0.5px solid var(--rule-2);
  color: var(--dim);
  font-family: ui-monospace, 'SF Mono', 'Courier New', monospace;
  font-size: 0.714rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 2px 7px;
  border-radius: 2px;
  cursor: pointer;
  transition: color 0.15s, border-color 0.15s;
  opacity: 0.6;
}
.theme-btn:hover { color: var(--ink); border-color: var(--ink); opacity: 1; }

/* ─── Typography ────────────────────────────────────────────────────── */

.eyebrow {
  font-family: ui-monospace, 'SF Mono', 'Courier New', monospace;
  font-size: 0.714rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--dim);
}

.display {
  font-family: 'Inter', sans-serif;
  font-weight: 900;
  font-size: clamp(4rem, 11vw, 12rem);
  line-height: 0.88;
  letter-spacing: -0.05em;
  color: var(--ink);
  text-transform: lowercase;
}

.display-aofn {
  margin-left: 0.2em;
  font-size: clamp(10px, 1vw, 14px);
  letter-spacing: 0.3em;
  color: var(--dim);
  vertical-align: super;
  font-weight: 700;
  text-transform: uppercase;
}

.h2 {
  font-family: 'Inter', sans-serif;
  font-weight: 700;
  font-size: 0.857rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--ink);
}

.h3 {
  font-weight: 400;
  font-size: 1rem;
  color: var(--ink);
  margin-bottom: 8px;
}

p {
  color: var(--body);
  margin-bottom: 12px;
  max-width: 56ch;
}
p:last-child { margin-bottom: 0; }

.num {
  font-family: ui-monospace, 'SF Mono', 'Courier New', monospace;
  font-size: 0.786rem;
  color: var(--ink);
  letter-spacing: 0.05em;
}

a {
  color: var(--ink);
  text-decoration: none;
  border-bottom: 0.5px solid var(--dim);
  transition: border-color 0.12s;
}
a:hover { border-color: var(--ink); }

/* ─── Rules ─────────────────────────────────────────────────────────── */

.rule   { height: 0; border-top: 0.5px solid var(--rule);   margin: 0; }
.rule-2 { height: 0; border-top: 1px   solid var(--rule-2); margin: 0; }

/* ─── Top header ────────────────────────────────────────────────────── */

.top {
  display: grid;
  grid-template-columns: 80px 1fr auto;
  align-items: baseline;
  gap: var(--col-gap);
  margin-bottom: 24px;
}
.top .right {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 12px;
  text-align: right;
  color: var(--dim);
}

/* ─── Display block ─────────────────────────────────────────────────── */

.display-block {
  padding: 24px 0 80px;
  margin-top: 2em;
}
.display-block .subline {
  margin-top: 24px;
  color: var(--body);
  font-size: 1.286rem;
  line-height: 1.35;
  max-width: none;
}

/* ─── Intro ─────────────────────────────────────────────────────────── */

.intro {
  display: grid;
  grid-template-columns: 80px 1fr 1fr;
  gap: var(--col-gap);
  padding: 32px 0 64px;
}

.meta-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px 24px;
  margin-top: 16px;
}
.meta-list dt {
  color: var(--dim);
  font-size: 0.786rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  font-family: ui-monospace, 'SF Mono', 'Courier New', monospace;
}
.meta-list dd { color: var(--ink); font-size: 0.929rem; }

/* ─── Contents ──────────────────────────────────────────────────────── */

.contents { margin: 80px 0 120px; }

.toc-row {
  display: grid;
  grid-template-columns: 80px 280px 80px 1fr 80px;
  gap: var(--col-gap);
  padding: 20px 0;
  align-items: baseline;
}
.toc-row + .toc-row { border-top: 0.5px solid var(--rule); }
.toc-row .ch-title {
  font-family: 'Inter', sans-serif;
  font-weight: 700;
  font-size: 0.929rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}
.toc-row .sec-num {
  font-family: ui-monospace, 'SF Mono', 'Courier New', monospace;
  font-size: 0.786rem;
  color: var(--dim);
}
.toc-row .sec-title {
  font-family: ui-monospace, 'SF Mono', 'Courier New', monospace;
  font-size: 0.786rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--ink);
}
.toc-row .page {
  font-family: ui-monospace, 'SF Mono', 'Courier New', monospace;
  font-size: 0.786rem;
  color: var(--dim);
  text-align: right;
}
.toc-row .stacked > div + div { margin-top: 8px; }
.toc-row a { color: inherit; border-bottom: 0.5px solid transparent; }
.toc-row a:hover { border-color: var(--ink); }
.toc-row .num a { font-family: ui-monospace, 'SF Mono', 'Courier New', monospace; }

/* ─── Chapters ──────────────────────────────────────────────────────── */

.chapter,
.chapter .ch-body section[id] { scroll-margin-top: 20px; }

.chapter {
  display: grid;
  grid-template-columns: 80px 280px 1fr;
  gap: var(--col-gap);
  padding: 48px 0;
  border-top: 0.5px solid var(--rule);
}
.chapter .ch-meta .num { display: block; margin-bottom: 12px; }
.chapter .ch-title h2 {
  font-family: 'Inter', sans-serif;
  font-weight: 700;
  font-size: 0.929rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  line-height: 1.3;
}
.chapter .ch-body section + section { margin-top: 36px; }
.chapter .ch-body .sec-eyebrow {
  font-family: ui-monospace, 'SF Mono', 'Courier New', monospace;
  font-size: 0.786rem;
  color: var(--dim);
  letter-spacing: 0.06em;
  margin-bottom: 6px;
}
.chapter .ch-body h3 { margin-bottom: 10px; }
.chapter .ch-body ul { list-style: none; margin: 8px 0 0; }
.chapter .ch-body li {
  padding: 8px 0;
  border-top: 0.5px solid var(--rule);
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 16px;
  color: var(--body);
  font-size: 0.929rem;
}
.chapter .ch-body li:last-child { border-bottom: 0.5px solid var(--rule); }
.chapter .ch-body li .lbl { color: var(--ink); }

/* ─── Accent bar ────────────────────────────────────────────────────── */

.accent-bar {
  height: 28px;
  background: var(--accent);
  margin-top: 80px;
  width: 240px;
  opacity: 0.2;
}

/* ─── Footer ────────────────────────────────────────────────────────── */

.footer {
  margin-top: 120px;
  padding-top: 16px;
  border-top: 0.5px solid var(--rule);
  display: grid;
  grid-template-columns: 80px 1fr auto;
  gap: var(--col-gap);
  align-items: baseline;
  color: var(--dim);
  font-size: 0.786rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  font-family: ui-monospace, 'SF Mono', 'Courier New', monospace;
}

/* ─── Responsive ────────────────────────────────────────────────────── */

@media (max-width: 720px) {
  body { padding: 48px 24px 96px; }
  .top, .intro, .toc-row, .chapter, .footer {
    grid-template-columns: 1fr;
    gap: 12px;
  }
  .display-block { padding: 16px 0 48px; }
  .accent-bar { width: 100%; }
  .chapter .ch-body li { grid-template-columns: 1fr; gap: 4px; }
}