.site-header {
  position: relative;
  z-index: 20;
  border-bottom: 1px solid color-mix(in srgb, var(--accent) 60%, var(--line));
  background: rgb(247 242 232 / 96%);
}

.masthead {
  min-height: 68px;
  padding: 0.8rem 2.5rem;
  display: grid;
  grid-template-columns: minmax(18rem, 1fr) auto;
  align-items: center;
  gap: 1.5rem;
  background: var(--crimson);
  color: var(--paper-bright);
}

.site-title {
  display: block;
  width: fit-content;
  font-family: var(--display);
  font-size: clamp(1.55rem, 2.7vw, 2.45rem);
  font-weight: 700;
  letter-spacing: -0.035em;
  line-height: 1;
  text-decoration: none;
}

.site-kind {
  margin: 0.4rem 0 0;
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.masthead-actions {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.primary-nav {
  max-width: 1488px;
  min-height: 50px;
  margin: 0 auto;
  padding: 0 2.5rem;
  display: flex;
  align-items: stretch;
  gap: clamp(1.4rem, 3vw, 3.2rem);
  overflow-x: auto;
  scrollbar-width: none;
}

.primary-nav::-webkit-scrollbar {
  display: none;
}

.primary-nav a {
  position: relative;
  display: grid;
  place-items: center;
  min-width: max-content;
  min-height: 48px;
  color: var(--muted);
  font-family: var(--display);
  font-size: 1.05rem;
  text-decoration: none;
}

.primary-nav a::after {
  content: "";
  position: absolute;
  inset: auto 0 0;
  height: 3px;
  background: var(--tab-accent, var(--accent));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 220ms var(--ease-in-out);
}

.primary-nav a[aria-current="page"] {
  color: var(--tab-accent, var(--accent-dark));
  font-weight: 700;
}

.primary-nav [data-view-link="geography"] { --tab-accent: #a31332; }
.primary-nav [data-view-link="countries"] { --tab-accent: #155e9a; }
.primary-nav [data-view-link="composition"] { --tab-accent: #9a5b00; }
.primary-nav [data-view-link="formation"] { --tab-accent: #176b63; }
.primary-nav [data-view-link="methods"] { --tab-accent: #46505c; }

.primary-nav a[aria-current="page"]::after {
  transform: scaleX(1);
}

#main-content {
  min-height: calc(100vh - 118px);
}

.page {
  --section-pad: clamp(1.4rem, 3.2vw, 3rem);
}

body[data-transition="view"] .page {
  animation: page-enter 240ms var(--ease-out) both;
}

.chapter-title:focus {
  outline: none;
}

.page-inner {
  width: min(100%, 1488px);
  margin: 0 auto;
  padding: clamp(1.25rem, 2.5vw, 2.25rem) var(--section-pad) var(--section-pad);
}

.chapter-header {
  display: grid;
  grid-template-columns: auto 1px minmax(min-content, 0.7fr) minmax(29rem, 1.3fr);
  gap: clamp(1rem, 2vw, 2rem);
  align-items: start;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--accent);
}

.chapter-number,
.chapter-title,
.finding-title,
.map-title,
.scale-value {
  font-family: var(--display);
  font-variant-numeric: lining-nums tabular-nums;
}

.chapter-number {
  color: var(--accent);
  font-size: clamp(3.4rem, 6vw, 5.6rem);
  font-weight: 700;
  letter-spacing: -0.055em;
  line-height: 0.84;
}

.chapter-divider {
  width: 1px;
  height: clamp(3.2rem, 6vw, 5rem);
  background: var(--accent);
}

.chapter-title {
  min-width: 0;
  margin: -0.1em 0 0;
  color: var(--accent);
  font-size: clamp(2.5rem, 5vw, 5rem);
  font-weight: 700;
  letter-spacing: -0.055em;
  line-height: 0.92;
  overflow-wrap: break-word;
}

.finding-block {
  grid-column: 4;
  margin-top: 0;
  max-width: 73rem;
}

.finding-title {
  margin: 0;
  max-width: 68rem;
  font-size: clamp(1.8rem, 2.7vw, 3.15rem);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 1.02;
}

.finding-deck {
  max-width: 72rem;
  margin: 0.5rem 0 0;
  color: #333039;
  font-family: var(--display);
  font-size: clamp(1.05rem, 1.55vw, 1.4rem);
  line-height: 1.35;
}

.evidence-toolbar {
  display: flex;
  justify-content: space-between;
  gap: 1rem;
  align-items: center;
  padding: 0.9rem 0;
}

.atlas-field {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(13.5rem, 0.43fr) minmax(0, 1fr);
  gap: clamp(1.2rem, 2.4vw, 2.5rem);
  align-items: stretch;
  min-height: 540px;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  padding: 1.25rem 0;
}

.evidence-figure {
  margin: 0;
}

.map-panel,
.scale-panel {
  min-width: 0;
}

.scale-panel {
  border-inline: 1px solid var(--line);
  padding: 0 clamp(1rem, 2vw, 1.8rem);
}

.figure-footer {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 1.5rem;
  align-items: start;
  padding: 1rem 0 0;
}

.page-break {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 66px;
  padding: 0 2.5rem;
  background: var(--next-accent, var(--accent));
  color: white;
  text-decoration: none;
}

@keyframes page-enter {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
}