@font-face {
  font-family: "undefined-medium";
  src:
    url("fonts/undefined-medium.woff2") format("woff2"),
    url("fonts/undefined-medium.woff") format("woff");
  font-weight: normal;
  font-style: normal;
}

:root {
  --paper: #f7f6f4;
  --ink: #1a1816;
  --body: #4a4742;
  --dim: #8a857c;
  --rule: #e8e6e1;
  --rule-2: #d8d5ce;
  --accent: #433eed;

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

[data-theme="dark"] {
  --paper: #1a1917;
  --ink: #f0ece4;
  --body: #a09890;
  --dim: #5a524a;
  --rule: #2e2b27;
  --rule-2: #3d3830;
  --accent: #6e6af0;
}

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

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

.theme-btn {
  background: none;
  border: 0.5px solid var(--rule-2);
  color: var(--dim);
  font-family: "undefined-medium", ui-monospace, 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;
}
.theme-btn:hover {
  color: var(--ink);
  border-color: var(--ink);
}

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

/* Typography ──────────────────────────────────────────────────────── */
.eyebrow {
  font-family: "undefined-medium", ui-monospace, monospace;
  font-size: 0.714rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--dim);
}

.display {
  font-weight: 900;
  font-size: clamp(4.571rem, 11vw, 13.143rem);
  line-height: 0.9;
  letter-spacing: -0.03em;
}

.h2 {
  font-weight: 700;
  font-size: 1rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--ink);
}

.h3 {
  font-weight: 500;
  font-size: 1rem;
  color: var(--ink);
  margin-bottom: 6px;
}

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

.num {
  font-family: "undefined-medium", ui-monospace, monospace;
  font-size: 0.786rem;
  color: var(--ink);
  letter-spacing: 0.05em;
}

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

/* Top header ──────────────────────────────────────────────────────── */
.top {
  display: grid;
  grid-template-columns: 80px 1fr auto;
  align-items: baseline;
  gap: var(--col-gap);
  margin-bottom: 24px;
}
.top .num {
  padding-top: 4px;
}
.top .right {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 12px;
  text-align: right;
  color: var(--dim);
}

.display-block {
  position: relative;
  padding: 24px 0 80px;
  margin-top: 2em;
}

.display-plus {
  font-size: 0.8em;
  font-weight: 100;
  color: var(--accent);
  position: relative;
  top: -0.75em;
}
.display-block .display {
  color: var(--ink);
}
.display-block .subline {
  margin-top: 24px;
  color: var(--body);
  font-size: 1.286rem;
  line-height: 1.35;
}

/* Intro grid ──────────────────────────────────────────────────────── */
.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: "undefined-medium", monospace;
}
.meta-list dd {
  color: var(--ink);
  font-size: 0.929rem;
}

/* Contents grid ───────────────────────────────────────────────────── */
.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-weight: 700;
  font-size: 0.929rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}
.toc-row .sec-num {
  font-family: "undefined-medium", monospace;
  font-size: 0.786rem;
  color: var(--dim);
}
.toc-row .sec-title {
  font-family: "undefined-medium", monospace;
  font-size: 0.786rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--ink);
}
.toc-row .page {
  font-family: "undefined-medium", monospace;
  font-size: 0.786rem;
  color: var(--dim);
  text-align: right;
}

.toc-row .stacked > div + div {
  margin-top: 8px;
}
.toc-row a {
  color: inherit;
  text-decoration: none;
  border-bottom: 0.5px solid transparent;
  transition: border-color 0.12s;
}
.toc-row a:hover {
  border-color: var(--ink);
}
.toc-row .num a {
  font-family: "undefined-medium", ui-monospace, monospace;
}

/* Chapter ─────────────────────────────────────────────────────────── */
.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-weight: 700;
  font-size: 1rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  line-height: 1.3;
}

.chapter .ch-body section + section {
  margin-top: 32px;
}
.chapter .ch-body .sec-eyebrow {
  font-family: "undefined-medium", 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);
}

kbd {
  font-family: "undefined-medium", monospace;
  font-size: 0.786rem;
  background: transparent;
  border: 0.5px solid var(--rule-2);
  padding: 1px 6px;
  border-radius: 2px;
  color: var(--ink);
}

/* 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: "undefined-medium", monospace;
}
.accent-bar {
  height: 28px;
  background: var(--accent);
  margin-top: 80px;
  width: 240px;
}

/* 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 56px;
  }
  .accent-bar {
    width: 100%;
  }
  .chapter .ch-body li {
    grid-template-columns: 1fr;
    gap: 4px;
  }
}