.understanding-heading,
.historical-readability-hero,
.historical-readability-layout {
  max-width: 1120px;
  margin-inline: auto;
}

.understanding-heading .lede {
  max-width: 780px;
}

.understanding-concept-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
  max-width: 1120px;
  margin: 28px auto;
}

.understanding-concept-card {
  min-width: 0;
  padding: clamp(22px, 3vw, 34px);
  border: 1px solid var(--line);
  border-radius: 18px;
  background: var(--panel);
}

.understanding-concept-card--featured {
  grid-column: 1 / -1;
  background: linear-gradient(135deg, #edf5f5, var(--panel) 62%);
  border-color: color-mix(in srgb, var(--accent) 42%, var(--line));
}

.understanding-concept-card h2 {
  margin: 6px 0 10px;
}

.understanding-concept-card p:last-child {
  margin-bottom: 0;
}

.understanding-faq {
  max-width: 880px;
  margin: 40px auto 0;
}

.understanding-faq details {
  border-top: 1px solid var(--line);
  padding: 16px 0;
}

.understanding-faq summary {
  color: var(--accent-dark);
  font-weight: 700;
  cursor: pointer;
}

.understanding-faq details p {
  max-width: 760px;
  margin-bottom: 0;
}

.historical-readability-article {
  --article-measure: 740px;
}

.understanding-breadcrumb {
  color: var(--muted);
  font-size: .92rem;
}

.understanding-breadcrumb span {
  margin-inline: 8px;
}

.historical-readability-hero h1 {
  max-width: 900px;
  margin-bottom: 14px;
  font-size: clamp(2.5rem, 6vw, 5.3rem);
  line-height: .98;
  letter-spacing: -.045em;
}

.historical-readability-deck {
  max-width: 820px;
  color: var(--ink);
  font-size: clamp(1.15rem, 2vw, 1.42rem);
  line-height: 1.5;
}

.historical-readability-picture {
  display: block;
  overflow: hidden;
  margin-top: 30px;
  border-radius: 20px;
  background: #172026;
}

.historical-readability-picture img {
  display: block;
  width: 100%;
  height: auto;
}

.historical-readability-caption {
  margin: 10px 4px 0;
  color: var(--muted);
  font-size: .88rem;
}

.historical-readability-layout {
  display: grid;
  grid-template-columns: 220px minmax(0, var(--article-measure));
  justify-content: center;
  gap: clamp(34px, 6vw, 78px);
  align-items: start;
  margin-top: 50px;
}

.historical-readability-toc {
  position: sticky;
  top: calc(var(--site-sticky-offset) + 28px);
  padding: 18px 0;
  border-block: 1px solid var(--line);
}

.historical-readability-toc ol {
  margin: 10px 0 0;
  padding-left: 20px;
}

.historical-readability-toc li {
  margin: 8px 0;
  color: var(--muted);
  font-size: .9rem;
}

.historical-readability-copy {
  min-width: 0;
}

.historical-readability-copy section {
  scroll-margin-top: calc(var(--site-sticky-offset) + 24px);
  margin-bottom: 64px;
}

.historical-readability-copy h2 {
  margin: 0 0 18px;
  font-size: clamp(1.7rem, 3vw, 2.45rem);
  line-height: 1.12;
  letter-spacing: -.025em;
}

.historical-readability-copy h3 {
  margin: 38px 0 12px;
  font-size: 1.3rem;
}

.historical-readability-copy p,
.historical-readability-copy li {
  font-size: 1.04rem;
}

.historical-readability-copy li {
  margin: 10px 0;
}

.historical-readability-copy blockquote {
  margin: 30px 0;
  padding: 8px 0 8px 24px;
  border-left: 4px solid var(--accent);
  color: var(--accent-dark);
  font-size: 1.13rem;
}

.historical-readability-note {
  margin: 28px 0;
  padding: 22px 24px;
  border: 1px solid var(--line);
  border-radius: 14px;
  background: var(--surface-soft);
}

.historical-readability-note h3 {
  margin-top: 0;
}

.historical-readability-chain {
  display: grid;
  gap: 12px;
  margin: 28px 0 12px;
  padding: 0;
  list-style: none;
  counter-reset: none;
}

.historical-readability-chain li {
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: 15px;
  align-items: start;
  margin: 0;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--panel);
}

.historical-readability-chain-number {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  border-radius: 50%;
  background: var(--accent-dark);
  color: #fff;
  font-weight: 800;
}

.historical-readability-chain strong,
.historical-readability-chain span {
  display: block;
}

.historical-readability-chain li div span,
.historical-readability-chain-result span {
  margin-top: 4px;
  color: var(--muted);
}

.historical-readability-chain-result {
  margin: 0 0 28px;
  padding: 20px;
  border-radius: 12px;
  background: #e7f1f2;
  box-shadow: inset 4px 0 0 var(--accent);
}

.historical-readability-chain-result strong,
.historical-readability-chain-result span {
  display: block;
}

.historical-readability-closing {
  padding: clamp(26px, 5vw, 46px);
  border-radius: 18px;
  background: var(--accent-dark);
  color: #fff;
}

.historical-readability-closing a,
.historical-readability-closing .eyebrow {
  color: #d6eff0;
}

.historical-readability-next {
  margin-bottom: 0;
}

.historical-readability-sources {
  padding-top: 28px;
  border-top: 1px solid var(--line);
}

@media (max-width: 900px) {
  .historical-readability-layout {
    grid-template-columns: minmax(0, var(--article-measure));
  }

  .historical-readability-toc {
    position: static;
  }
}

@media (max-width: 680px) {
  .understanding-concept-grid {
    grid-template-columns: 1fr;
  }

  .understanding-concept-card--featured {
    grid-column: auto;
  }

  .historical-readability-hero h1 {
    font-size: clamp(2.35rem, 13vw, 3.5rem);
  }

  .historical-readability-picture {
    border-radius: 12px;
  }

  .historical-readability-copy p,
  .historical-readability-copy li {
    font-size: 1rem;
  }

  .historical-readability-copy blockquote {
    margin-inline: 0;
    padding-left: 18px;
  }
}