.deepdoc-hero {
  position: relative;
  overflow: hidden;
  border-bottom: var(--line-heavy) solid var(--color-accent-dark);
  background-color: var(--color-panel-alt);
  background-image:
    linear-gradient(var(--color-tile-line) var(--line-thin), var(--color-transparent) var(--line-thin)),
    linear-gradient(90deg, var(--color-tile-line) var(--line-thin), var(--color-transparent) var(--line-thin));
  background-size: 32px 32px;
}

.deepdoc-hero::after {
  position: absolute;
  right: -8%;
  bottom: -38%;
  width: 48%;
  height: 82%;
  pointer-events: none;
  border-top: var(--line-medium) solid var(--color-border);
  background-color: var(--color-water-wash);
  transform: rotate(-8deg);
  content: "";
}

.deepdoc-hero-grid {
  position: relative;
  z-index: 2;
  min-height: 590px;
  padding-top: clamp(72px, 9vw, 128px);
  padding-bottom: clamp(72px, 9vw, 128px);
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) minmax(290px, 0.62fr);
  align-items: center;
  gap: clamp(40px, 7vw, 96px);
}

.deepdoc-intro {
  max-width: 900px;
}

.deepdoc-intro h1 {
  max-width: 850px;
  margin-bottom: 28px;
  font-size: clamp(54px, 7.2vw, 104px);
  line-height: 0.98;
}

.deepdoc-summary {
  max-width: 760px;
  margin-bottom: 30px;
  color: var(--color-text-muted);
  font-size: clamp(17px, 2vw, 22px);
  line-height: 1.8;
}

.deepdoc-index-board {
  position: relative;
  border: var(--line-heavy) solid var(--color-accent-dark);
  background-color: var(--color-panel);
}

.deepdoc-index-board::before {
  position: absolute;
  top: calc(var(--line-heavy) * -1);
  left: 0;
  width: 112px;
  height: var(--line-heavy);
  background-color: var(--color-warn);
  content: "";
}

.deepdoc-board-code {
  margin: 0;
  padding: 13px 16px;
  color: var(--color-white);
  background-color: var(--color-accent-dark);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 850;
  letter-spacing: 0.08em;
}

.deepdoc-index-board dl {
  margin: 0;
}

.deepdoc-index-board dl > div {
  padding: 17px 18px;
  border-bottom: var(--line-thin) solid var(--color-border);
}

.deepdoc-index-board dl > div:last-child {
  border-bottom: 0;
}

.deepdoc-index-board dt {
  margin-bottom: 4px;
  color: var(--color-accent-dark);
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 850;
  letter-spacing: 0.08em;
}

.deepdoc-index-board dd {
  margin: 0;
  color: var(--color-text-muted);
  font-size: 13px;
  line-height: 1.65;
}

.deepdoc-route {
  padding-bottom: 30px;
}

.deepdoc-relationship {
  max-width: var(--reading-width);
  margin-inline: auto;
}

.deepdoc-relationship p:last-child {
  margin-bottom: 0;
}

.deepdoc-relationship a {
  color: var(--color-accent-dark);
  font-weight: 800;
  text-decoration: underline;
  text-decoration-color: var(--color-warn);
  text-decoration-thickness: var(--line-medium);
  text-underline-offset: 4px;
}

.deepdoc-route-label {
  margin-bottom: 7px;
  color: var(--color-accent-dark);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 850;
  letter-spacing: 0.09em;
  text-transform: uppercase;
}

.deepdoc-toc {
  max-width: var(--reading-width);
  margin: 28px auto 0;
}

.deepdoc-prose {
  padding-bottom: var(--section-space);
}

.deepdoc-chapter {
  padding-top: clamp(48px, 7vw, 88px);
}

.deepdoc-chapter:first-child {
  padding-top: 42px;
}

.deepdoc-chapter h2 {
  scroll-margin-top: calc(var(--header-height) + 78px);
}

.deepdoc-chapter h2::before {
  width: 84px;
  height: var(--line-heavy);
  margin-bottom: 18px;
  display: block;
  background-color: var(--color-warn);
  content: "";
}

.deepdoc-chapter h3 {
  padding-left: 16px;
  border-left: var(--line-heavy) solid var(--color-accent);
}

.deepdoc-chapter .table-wrap {
  margin: 30px 0;
  border-bottom: var(--line-medium) solid var(--color-accent-dark);
}

.deepdoc-chapter td:first-child {
  color: var(--color-text);
  font-weight: 800;
}

.deepdoc-decision {
  margin: 32px 0;
  padding: clamp(22px, 4vw, 34px);
  border: var(--line-heavy) solid var(--color-accent-dark);
  background-color: var(--color-panel-alt);
}

.deepdoc-decision-title {
  margin-bottom: 18px;
  color: var(--color-text);
  font-family: var(--font-display);
  font-size: 24px;
  font-weight: 900;
}

.deepdoc-decision ol {
  margin-bottom: 0;
  padding-left: 24px;
}

.deepdoc-decision li {
  padding-left: 5px;
}

@media (max-width: 860px) {
  .deepdoc-hero-grid {
    min-height: 0;
    grid-template-columns: 1fr;
  }

  .deepdoc-index-board {
    max-width: 560px;
  }

  .deepdoc-hero::after {
    right: -24%;
    width: 74%;
  }
}

@media (max-width: 640px) {
  .deepdoc-hero-grid {
    padding-top: 58px;
    padding-bottom: 58px;
    gap: 34px;
  }

  .deepdoc-intro h1 {
    font-size: clamp(46px, 15vw, 66px);
  }

  .deepdoc-summary {
    font-size: 17px;
  }

  .deepdoc-route {
    padding-top: 56px;
  }

  .deepdoc-toc {
    margin-top: 22px;
  }

  .deepdoc-chapter {
    padding-top: 64px;
  }

  .deepdoc-chapter h3 {
    padding-left: 12px;
  }
}