:root {
  --doc-copy-max: 820px;
  --doc-index-width: 150px;
  --doc-hero-space: clamp(76px, 10vw, 138px);
  --doc-grid-size: 52px;
  --doc-marker-size: 7px;
  --doc-sticky-offset: 92px;
}

.doc-hero {
  position: relative;
  overflow: hidden;
  padding-top: var(--doc-hero-space);
  padding-bottom: var(--doc-hero-space);
  border-bottom: var(--line-thin) solid var(--color-line);
  background:
    linear-gradient(to right, rgba(var(--color-accent-rgb), .025) var(--line-thin), var(--color-transparent) var(--line-thin)),
    linear-gradient(to bottom, rgba(var(--color-accent-rgb), .025) var(--line-thin), var(--color-transparent) var(--line-thin)),
    radial-gradient(circle at 78% 32%, rgba(var(--color-accent-rgb), .1), var(--color-transparent) 34%);
  background-size: var(--doc-grid-size) var(--doc-grid-size), var(--doc-grid-size) var(--doc-grid-size), auto;
}

.doc-hero::after {
  position: absolute;
  top: 0;
  right: 12%;
  width: var(--line-thin);
  height: 72%;
  content: "";
  background: linear-gradient(to bottom, var(--color-transparent), var(--color-accent), var(--color-transparent));
  opacity: .55;
}

.doc-hero h1 {
  max-width: 760px;
  margin-top: 24px;
  font-size: clamp(34px, 3.5vw, 48px);
}

.doc-hero .lede {
  margin-top: 24px;
}

.doc-facts {
  display: flex;
  max-width: 100%;
  flex-wrap: wrap;
  margin-top: 34px;
  border-top: var(--line-thin) solid var(--color-line);
  border-left: var(--line-thin) solid var(--color-line);
}

.doc-facts span {
  display: inline-flex;
  min-height: 40px;
  align-items: center;
  padding: 8px 13px;
  border-right: var(--line-thin) solid var(--color-line);
  border-bottom: var(--line-thin) solid var(--color-line);
  background: rgba(var(--color-bg-rgb), .72);
  color: var(--color-text-muted);
  font: .72rem/1.4 var(--font-mono);
}

.doc-intro {
  padding-bottom: clamp(64px, 8vw, 104px);
}

.intro-grid {
  display: grid;
  grid-template-columns: minmax(230px, .7fr) minmax(0, 1.3fr);
  gap: clamp(36px, 7vw, 96px);
  align-items: start;
}

.intro-grid h2 {
  margin-top: 18px;
}

.doc-toc {
  margin-top: 56px;
}

.doc-body {
  border-top: var(--line-thin) solid var(--color-line);
}

.doc-chapter {
  position: relative;
  padding-top: var(--section-space);
  padding-bottom: var(--section-space);
  border-bottom: var(--line-thin) solid var(--color-line);
  scroll-margin-top: var(--header-height);
}

.doc-layout {
  display: grid;
  grid-template-columns: var(--doc-index-width) minmax(0, var(--doc-copy-max));
  justify-content: center;
  gap: clamp(34px, 7vw, 92px);
}

.chapter-index {
  position: sticky;
  top: var(--doc-sticky-offset);
  display: flex;
  height: max-content;
  flex-direction: column;
  gap: 12px;
  padding-top: 8px;
  color: var(--color-text-muted);
  font: .68rem/1.5 var(--font-mono);
  letter-spacing: .11em;
}

.chapter-index::before {
  width: 2px;
  height: 24px;
  content: "";
  background: linear-gradient(to bottom, var(--color-accent), rgba(var(--color-accent-rgb), .16));
}

.chapter-index span:first-child {
  color: var(--color-accent);
  font-size: .88rem;
}

.chapter-content {
  max-width: var(--doc-copy-max);
}

.chapter-content > h2:first-child {
  margin-top: 0;
}

.chapter-content h2 {
  padding-bottom: 22px;
  border-bottom: var(--line-thin) solid var(--color-line);
}

.chapter-content h3 {
  font-size: clamp(19px, 1.8vw, 23px);
}

.chapter-content .data-table,
.chapter-content .callout,
.chapter-content pre,
.chapter-content .selection-matrix {
  margin-top: 2em;
  margin-bottom: 2em;
}

.chapter-content td:first-child {
  color: var(--color-text);
  font-family: var(--font-mono);
  font-size: .82rem;
}

.selection-matrix {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: var(--line-thin) solid var(--color-line);
  border-left: var(--line-thin) solid var(--color-line);
}

.selection-matrix > div {
  min-width: 0;
  padding: 24px;
  border-right: var(--line-thin) solid var(--color-line);
  border-bottom: var(--line-thin) solid var(--color-line);
  background: var(--color-panel);
}

.selection-matrix h3 {
  margin-top: 10px;
  font-size: 1.08rem;
}

.selection-matrix p {
  margin-top: 10px;
  color: var(--color-text-muted);
  font-size: .9rem;
}

@media (max-width: 820px) {
  .intro-grid {
    grid-template-columns: 1fr;
  }

  .doc-layout {
    grid-template-columns: 1fr;
  }

  .chapter-index {
    position: static;
    flex-direction: row;
    align-items: center;
    padding-top: 0;
  }

  .chapter-index::before {
    width: 16px;
    height: 2px;
    flex: 0 0 auto;
    background: linear-gradient(to right, var(--color-accent), rgba(var(--color-accent-rgb), .16));
  }
}

@media (max-width: 640px) {
  :root {
    --doc-grid-size: 38px;
  }

  .doc-hero {
    padding-top: 66px;
    padding-bottom: 66px;
  }

  .doc-hero h1 {
    font-size: clamp(24px, 7vw, 30px);
  }

  .doc-hero::after {
    right: 8%;
  }

  .doc-facts {
    align-items: stretch;
    flex-direction: column;
  }

  .doc-facts span {
    width: 100%;
  }

  .selection-matrix {
    grid-template-columns: 1fr;
  }

  .chapter-content h2 {
    padding-bottom: 18px;
  }
}