.container {
  width: min(100% - 2 * var(--gutter), var(--container));
  margin-inline: auto;
}

/* Top band: the brand phrases, static. */
.topbar {
  height: var(--topbar-h);
  overflow: hidden;
  background: var(--topbar-bg);
  color: var(--topbar-fg);
  border-bottom: 1px solid var(--ink);
}

.topbar__text {
  display: flex;
  align-items: center;
  justify-content: center; /* wider than the screen: it overflows both sides evenly */
  gap: .75rem;
  height: 100%;
  white-space: nowrap;
  font-weight: var(--fw-title);
  font-size: var(--fs-topbar);
  letter-spacing: .08em;
  text-transform: uppercase;
  line-height: 1;
}

.topbar__star { color: var(--topbar-star); flex: none; }

/* Header */
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  min-height: 104px;
}

.brand {
  display: flex;
  align-items: center;
  gap: .875rem;
  text-decoration: none;
  flex: none;
}

.badge {
  border: 2.5px solid var(--ink);
  border-radius: 50%;
  background: var(--surface);
}

.brand__name {
  font-family: var(--font-display);
  font-weight: var(--fw-title);
  font-size: var(--fs-brand);
  letter-spacing: var(--tracking-title);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 1.25rem;
}

.site-nav__account { display: flex; align-items: center; gap: 1rem; }
.site-nav__sign-in { display: inline-flex; align-items: center; min-height: 2.75rem; font-weight: var(--fw-ui); font-size: var(--fs-control); text-underline-offset: .25rem; }

.site-nav__links {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  font-weight: var(--fw-ui);
  font-size: var(--fs-control);
  line-height: var(--lh-ui);
}

.site-nav__links a {
  display: flex;
  align-items: center;
  min-height: 2.75rem;
  text-decoration: none;
  padding-block: .375rem;
  border-bottom: 3px solid transparent;
}

.site-nav__links a:hover { border-bottom-color: var(--ink); }
.site-nav__links a[aria-current="page"] { border-bottom-color: var(--accent); }

.site-nav__github {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
}

.language-switch {
  display: flex;
  border: var(--border-thin) solid var(--ink);
  border-radius: var(--radius-pill);
  overflow: hidden;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--fs-code);
  flex: none;
}

.language-switch__option {
  display: grid;
  place-items: center;
  width: 3rem;
  height: 2.75rem;
  text-decoration: none;
  background: var(--surface);
}

.language-switch__option[aria-current="true"] {
  background: var(--ink);
  color: var(--surface);
}

/* Railway track: section divider and footer rule. */
.rail {
  height: 36px;
  background:
    linear-gradient(var(--rail) 0 0) 0 10px / 100% 4px no-repeat,
    linear-gradient(var(--rail) 0 0) 0 26px / 100% 4px no-repeat,
    repeating-linear-gradient(90deg, transparent 0 6px, var(--rail-tie) 6px 18px, transparent 18px 46px);
}

/* Sections */
.section { padding-block: var(--section-pad-y); }

.section--white {
  background: var(--surface);
  border-block: var(--border-thin) solid var(--ink);
}

.section__title {
  font-size: var(--fs-section);
  line-height: var(--lh-title);
  letter-spacing: var(--tracking-display);
}

.section__title--narrow { max-width: 900px; }
.section__title--medium { font-size: var(--fs-editorial-title); }
.section__title--large { font-size: var(--fs-section); }

.section__lead {
  max-width: var(--reading-measure);
  margin-top: 2.5rem;
  font-size: var(--fs-reading-lead);
  line-height: var(--lh-body);
}

.section__lead--muted { color: var(--ink-muted); font-size: var(--fs-ui-body); }

.section__aside {
  color: var(--ink-muted);
  font-size: var(--fs-reading);
  line-height: var(--lh-body);
}

.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3.75rem;
  align-items: start;
}

.judgment .split { grid-template-columns: minmax(0, 1fr) 560px; }
.measure .split { grid-template-columns: minmax(0, 1fr) 500px; gap: 5rem; }

.prose > * + * { margin-top: .875rem; }
.prose p { max-width: var(--reading-measure); line-height: var(--lh-body); }

/* Footer */
.site-footer {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 2rem;
  padding-block: 3.5rem 5.5rem;
}

.site-footer__brand {
  display: flex;
  align-items: center;
  gap: 1.125rem;
}

.site-footer__handle {
  white-space: nowrap;
  font-family: var(--font-display);
  font-weight: var(--fw-title);
  font-size: var(--fs-brand);
  line-height: 1.1;
  letter-spacing: var(--tracking-title);
}

.site-footer__tagline { color: var(--ink-muted); font-size: var(--fs-control); line-height: var(--lh-ui); }

.site-footer__meta { text-align: right; }

.site-footer__links {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: .5rem 1.75rem;
  font-weight: var(--fw-ui);
  font-size: var(--fs-control);
}

.site-footer__links a { display: inline-flex; align-items: center; justify-content: center; min-width: var(--target-size); min-height: var(--target-size); text-underline-offset: 3px; text-decoration-thickness: 2px; }

.site-footer__copyright {
  margin-top: .75rem;
  font-family: var(--font-mono);
  font-size: var(--fs-caption);
  line-height: var(--lh-caption);
  color: var(--ink-muted);
}

@media (max-width: 1100px) {
  .site-nav__links { display: none; }
  .split, .judgment .split, .measure .split { grid-template-columns: 1fr; gap: 2rem; }
}

@media (max-width: 720px) {
  .site-header { min-height: 84px; }
  .site-nav { gap: .75rem; }
  .brand__name { display: none; }
  .brand .badge { width: 52px; height: 52px; }
  .topbar { height: 44px; }
  .topbar__text { font-size: var(--fs-control); }
  .site-footer { flex-direction: column; align-items: flex-start; }
  .site-footer__meta { text-align: left; }
  .site-footer__links { justify-content: flex-start; }
}

@media (max-width: 560px) {
  .site-header { gap: .75rem; }
  .site-header--public:has(.site-nav__account) { position: relative; min-height: 142px; align-items: flex-start; padding-top: .75rem; }
  .site-nav__account { position: absolute; left: 0; right: 0; bottom: .75rem; justify-content: flex-end; }
  .site-nav__account .button { flex: 1; max-width: 16rem; }
  .site-nav { min-width: 0; flex-wrap: wrap; justify-content: flex-end; padding-block: .75rem; }
  .site-footer__brand { gap: .75rem; }
  .site-footer__brand .badge { width: 64px; height: 64px; }
  .site-footer__brand > div { min-width: 0; }
}

.site-nav__menu { display: none; position: relative; }
.site-nav__menu summary { cursor: pointer; padding: .5rem; min-height: 2.75rem; font-weight: var(--fw-ui); }
.site-nav__menu-links { position: absolute; right: 0; top: 100%; z-index: 5; min-width: 12rem; border: var(--border-thin) solid var(--ink); border-radius: var(--radius-btn); background: var(--surface); box-shadow: var(--shadow-hard); }
.site-nav__menu-links a { display: flex; align-items: center; gap: .5rem; padding: .75rem 1rem; }
@media (max-width: 1100px) { .site-nav__menu { display: block; } }