.site-header {
  border-bottom: 1px solid var(--colour-rule);
  padding: var(--space-4) var(--space-5);
}

.site-inner {
  max-width: var(--page-max);
  margin-inline: auto;
}

.site-nav {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-5);
  align-items: center;
  justify-content: space-between;
  max-width: var(--page-max);
  margin-inline: auto;
}

.site-nav a {
  text-decoration: none;
}

.site-nav-links {
  display: flex;
  gap: var(--space-5);
  align-items: center;
}

.site-brand {
  display: inline-flex;
  align-items: center;
  gap: var(--space-3);
  color: inherit;
}

.site-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 1.75rem;
  height: 1.75rem;
  background: var(--colour-fg);
  color: var(--colour-bg);
  border-radius: 50%;
  font-weight: 700;
  font-size: 0.95rem;
  line-height: 1;
}

.site-wordmark {
  font-variant-caps: all-small-caps;
  font-weight: 600;
  letter-spacing: 0.06em;
}

.site-footer {
  padding: var(--space-5);
  color: var(--colour-muted);
  font-size: var(--type-small);
}

.site-footer .site-inner {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3) var(--space-5);
  justify-content: space-between;
}

main {
  flex: 1;
  width: 100%;
  padding: var(--space-6) var(--space-5) var(--space-7);
  max-width: var(--page-max);
  margin-inline: auto;
}

.page, .post {
  max-width: var(--measure);
}

.playbook-layout {
  display: grid;
  grid-template-columns: 16rem 1fr;
  gap: var(--space-7);
  max-width: calc(16rem + 65ch + var(--space-7));
}

@media (max-width: 60em) {
  .playbook-layout {
    grid-template-columns: 1fr;
  }
}