.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1rem clamp(1rem, 3vw, 2rem);
  border-bottom: 1px solid var(--line);
  background: rgba(255, 251, 244, 0.88);
  backdrop-filter: blur(16px);
}

.site-header__brand a,
.site-nav a,
.site-header__toggle,
.page-sidebar__title,
.hero__eyebrow,
.pill,
.stage-card__eyebrow,
.hero__meta,
.back-link {
  font-family: "IBM Plex Sans", sans-serif;
}

.site-header__brand a {
  font-size: 1.04rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  text-decoration: none;
}

.site-header__brand p {
  margin: 0.15rem 0 0;
  color: var(--ink-muted);
  font-size: 0.84rem;
  line-height: 1.35;
}

.site-header__toggle {
  display: none;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: white;
  padding: 0.55rem 0.9rem;
  font-weight: 600;
}

.site-nav {
  display: flex;
  gap: 1rem;
}

.site-nav a {
  text-decoration: none;
  font-size: 0.9rem;
  font-weight: 600;
  letter-spacing: 0.01em;
}

.page-shell {
  width: min(calc(100% - 2rem), var(--max-width));
  margin: 0 auto;
  padding: 2rem 0 4rem;
}

.page-shell--with-sidebar {
  display: grid;
  grid-template-columns: 16rem minmax(0, 1fr);
  gap: 2rem;
}

.page-sidebar {
  position: relative;
}

.page-sidebar__inner {
  position: sticky;
  top: 5.5rem;
  padding: 1.2rem;
  border: 1px solid var(--line);
  border-radius: var(--radius-small);
  background: rgba(255, 255, 255, 0.62);
  box-shadow: var(--shadow);
}

.page-sidebar__title {
  margin: 0 0 0.9rem;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--ink-muted);
}

.page-sidebar ul {
  margin: 0;
  padding-left: 1rem;
}

.page-sidebar li + li {
  margin-top: 0.45rem;
}

.page-sidebar__item--level-2 {
  margin-left: 0.85rem;
}

.page-sidebar__link {
  display: inline-block;
  color: var(--accent-strong);
  text-decoration: none;
  font-family: "IBM Plex Sans", sans-serif;
  font-size: 0.89rem;
  font-weight: 600;
  line-height: 1.42;
}

.page-sidebar__link--level-2 {
  font-size: 0.82rem;
  font-weight: 500;
  color: var(--ink-muted);
}