.site-header,
body > nav[aria-label="Breadcrumb"],
main,
.site-footer {
  width: min(100% - 2 * var(--space-4), var(--page-width));
  margin-inline: auto;
}

.site-header {
  position: relative;
  z-index: 10;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto auto;
  align-items: center;
  gap: var(--space-3);
  min-height: 5.25rem;
  border-block-end: var(--border-thin) solid var(--color-border);
}

.site-header nav {
  display: flex;
  justify-content: flex-end;
  gap: var(--space-1);
  min-width: 0;
}

body > nav[aria-label="Breadcrumb"] {
  padding-block: var(--space-3);
}

main {
  padding-block: var(--space-6) var(--space-7);
}

main > :where(article, section) {
  min-width: 0;
}

main > section + section {
  margin-block-start: var(--space-7);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.6fr) minmax(16rem, 0.7fr);
  gap: var(--space-5) var(--space-7);
  align-items: end;
  min-height: min(42rem, 72vh);
  padding-block: var(--space-5) var(--space-7);
}

.hero h1 {
  grid-column: 1 / -1;
  max-width: 12ch;
  margin-block-end: 0;
}

.hero .site-purpose {
  align-self: start;
  font-size: var(--step-1);
  line-height: 1.45;
}

.hero > p:not(.site-purpose) {
  margin-block-end: 0;
}

.system-atlas {
  display: grid;
  grid-template-columns: minmax(12rem, 0.55fr) minmax(0, 1.45fr);
  gap: var(--space-5);
  border: var(--border-thin) solid var(--color-border);
  border-radius: var(--radius-large);
  padding: clamp(1.25rem, 4vw, 3.5rem);
  background: var(--color-canvas-raised);
  box-shadow: var(--shadow-high);
}

.system-atlas > p {
  grid-column: 1;
}

.system-nodes {
  grid-column: 2;
  grid-row: 1 / span 2;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-3);
  min-width: 0;
}

.learning-track,
.module-page,
.content-page {
  width: min(100%, var(--line-readable));
  margin-inline: auto;
}

.learning-track > header,
.module-page > header,
.content-page > h1 {
  margin-block-end: var(--space-6);
}

.learning-track > section,
.learning-module > section,
.content-body > section {
  margin-block-start: var(--space-5);
}

.learning-module > nav,
.learning-track nav {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.site-footer {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: var(--space-3);
  border-block-start: var(--border-thin) solid var(--color-border);
  padding-block: var(--space-5);
  color: var(--color-text-muted);
  font-size: var(--step--1);
}

.site-footer p {
  margin: 0;
}

@media (max-width: 58rem) {
  .site-header {
    grid-template-columns: minmax(0, 1fr) auto auto;
  }

  .site-header nav {
    grid-column: 1 / -1;
    grid-row: 2;
    justify-content: flex-start;
    overflow-x: auto;
    padding-block-end: var(--space-3);
  }

  .hero,
  .system-atlas {
    grid-template-columns: 1fr;
  }

  .hero {
    gap: var(--space-3);
    min-height: auto;
  }

  .system-atlas > p,
  .system-nodes {
    grid-column: 1;
    grid-row: auto;
  }
}

@media (max-width: 40rem) {
  .site-header,
  body > nav[aria-label="Breadcrumb"],
  main,
  .site-footer {
    width: min(100% - 2rem, var(--page-width));
  }

  .site-header {
    grid-template-columns: minmax(0, 1fr) auto;
    gap: var(--space-2);
    padding-block: var(--space-2);
  }

  .site-header nav {
    display: grid;
    grid-template-columns: 1fr;
    width: 100%;
    overflow: visible;
  }

  .site-header [data-theme-toggle] {
    grid-column: 1 / -1;
    justify-self: start;
  }

  .system-nodes {
    grid-template-columns: 1fr;
  }

  .site-footer {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 320px) {
  .site-header,
  body > nav[aria-label="Breadcrumb"],
  main,
  .site-footer {
    width: calc(100% - 1.5rem);
  }

  main {
    padding-block-start: var(--space-5);
  }
}