.skip-link {
  position: fixed;
  inset-block-start: var(--space-3);
  inset-inline-start: var(--space-3);
  z-index: 100;
  display: inline-flex;
  align-items: center;
  min-block-size: 44px;
  padding-inline: var(--space-3);
  color: var(--color-accent-ink);
  background: var(--color-accent);
  font-weight: 800;
  transform: translateY(calc(-100% - 2rem));
}

.skip-link:focus {
  transform: translateY(0);
}

.site-header [data-nav-toggle] {
  display: none;
}

.site-brand,
.site-header nav a,
.learning-module nav a,
.learning-track nav a,
.site-footer a,
.hero > p > a,
main li > a,
.glossary a,
.go-deeper a {
  display: inline-flex;
  align-items: center;
  min-block-size: 44px;
  min-inline-size: 44px;
}

.site-brand {
  gap: 0.45rem;
  color: var(--color-text);
  font-family: var(--font-display);
  font-size: var(--step-1);
  font-weight: 700;
  text-decoration: none;
  white-space: nowrap;
}

.site-brand::before {
  content: "";
  width: 0.72rem;
  height: 0.72rem;
  border: 2px solid var(--color-signal);
  border-radius: 50%;
  box-shadow: 0 0 0 0.25rem var(--color-halo);
}

.site-brand span {
  color: var(--color-text-muted);
  font-family: var(--font-body);
  font-size: var(--step--1);
  font-weight: 500;
}

.site-header nav a,
.learning-module nav a,
.learning-track nav a {
  border: var(--border-thin) solid transparent;
  border-radius: 999px;
  padding-inline: 0.85rem;
  color: var(--color-text-muted);
  font-size: var(--step--1);
  font-weight: 700;
  text-decoration: none;
}

.site-header nav a:hover,
.learning-module nav a:hover,
.learning-track nav a:hover,
.site-header nav a[aria-current="page"] {
  border-color: var(--color-border);
  color: var(--color-text);
  background: var(--color-surface);
}

.site-header nav a[aria-current="page"]::after {
  content: "";
  width: 0.42rem;
  height: 0.42rem;
  margin-inline-start: 0.5rem;
  border-radius: 50%;
  background: var(--color-signal);
}

body > nav[aria-label="Breadcrumb"] ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.25rem 0.5rem;
  margin: 0;
  padding: 0;
  color: var(--color-text-muted);
  font-size: var(--step--1);
  list-style: none;
}

body > nav[aria-label="Breadcrumb"] li {
  display: inline-flex;
  align-items: center;
  max-width: 100%;
}

body > nav[aria-label="Breadcrumb"] li + li::before {
  content: "→";
  margin-inline-end: 0.5rem;
  color: var(--color-signal);
}

body > nav[aria-label="Breadcrumb"] a {
  display: inline-flex;
  align-items: center;
  min-block-size: 44px;
}

.eyebrow,
.level {
  margin-block-end: var(--space-2);
  color: var(--color-signal);
  font-size: var(--step--1);
  font-weight: 800;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.hero::before {
  content: "SYSTEMS / ATLAS 01";
  grid-column: 1 / -1;
  align-self: end;
  color: var(--color-signal);
  font-family: var(--font-mono);
  font-size: var(--step--1);
  letter-spacing: 0.15em;
}

.hero .site-purpose {
  border-inline-start: 0.25rem solid var(--color-accent);
  padding-inline-start: var(--space-4);
}

.hero > p > a,
.go-deeper a {
  border-radius: 999px;
  padding-inline: 1rem;
  color: var(--color-accent-ink);
  background: var(--color-accent);
  font-weight: 800;
  text-decoration: none;
}

.hero > p > a::after,
.go-deeper a::after {
  content: "↗";
  margin-inline-start: 0.65rem;
}

.system-atlas h2 {
  max-width: 8ch;
  font-size: var(--step-3);
}

.system-atlas > p {
  color: var(--color-text-muted);
}

.system-nodes {
  counter-reset: atlas-node;
}

.system-nodes article {
  position: relative;
  min-height: 13rem;
  overflow: hidden;
  border: var(--border-thin) solid var(--color-border);
  border-radius: var(--radius-medium);
  padding: var(--space-4);
  background:
    linear-gradient(135deg, var(--color-halo), transparent 60%),
    var(--color-surface);
  counter-increment: atlas-node;
}

.system-nodes article::before {
  content: "0" counter(atlas-node);
  display: block;
  margin-block-end: var(--space-5);
  color: var(--color-signal);
  font-family: var(--font-mono);
  font-size: var(--step--1);
  letter-spacing: 0.15em;
}

.system-nodes article::after {
  content: "";
  position: absolute;
  inset-block-start: 1.45rem;
  inset-inline-end: 1.35rem;
  width: 0.65rem;
  height: 0.65rem;
  border: 2px solid var(--color-accent);
  border-radius: 50%;
}

.system-nodes article h3 {
  color: var(--color-accent);
}

.system-nodes article p {
  margin-block-end: 0;
  color: var(--color-text-muted);
  font-size: var(--step--1);
  line-height: 1.55;
}

main > section:not(.hero, .system-atlas) {
  border-block-start: var(--border-thin) solid var(--color-border);
  padding-block-start: var(--space-4);
}

main > section:not(.hero, .system-atlas) > h2 {
  max-width: 20ch;
}

main > section nav[aria-label="Pilih level pembelajaran"] {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--space-3);
  margin-block-start: var(--space-4);
}

main > section nav[aria-label="Pilih level pembelajaran"] a {
  display: flex;
  min-width: 0;
  min-height: 11rem;
  flex-direction: column;
  align-items: flex-start;
  justify-content: space-between;
  border: var(--border-thin) solid var(--color-border-strong);
  border-radius: var(--radius-medium);
  padding: var(--space-4);
  color: var(--color-text);
  background: var(--color-surface);
  text-decoration: none;
}

main > section nav[aria-label="Pilih level pembelajaran"] a:hover {
  border-color: var(--color-accent);
  box-shadow: var(--shadow-low);
}

main > section nav[aria-label="Pilih level pembelajaran"] strong {
  color: var(--color-accent);
  font-family: var(--font-display);
  font-size: var(--step-1);
}

main > section nav[aria-label="Pilih level pembelajaran"] span {
  color: var(--color-text-muted);
  line-height: 1.5;
}

.learning-outcome {
  max-width: 56ch;
  border-inline-start: 0.25rem solid var(--color-accent);
  padding-inline-start: var(--space-4);
  color: var(--color-text-muted);
  font-size: var(--step-1);
}

.learning-index {
  display: grid;
  gap: var(--space-2);
  margin: 0;
  padding: 0;
  counter-reset: learning-step;
  list-style: none;
}

.learning-index li {
  position: relative;
  min-width: 0;
  counter-increment: learning-step;
}

.learning-index li::before {
  content: counter(learning-step, decimal-leading-zero);
  position: absolute;
  inset-block: 0;
  inset-inline-start: var(--space-3);
  z-index: 1;
  display: grid;
  align-items: center;
  color: var(--color-signal);
  font-family: var(--font-mono);
  font-size: var(--step--1);
  pointer-events: none;
}

.learning-index a {
  width: 100%;
  min-height: 4.4rem;
  border: var(--border-thin) solid var(--color-border-strong);
  border-radius: var(--radius-small);
  padding: 0.85rem var(--space-3) 0.85rem 4rem;
  color: var(--color-text);
  background: var(--color-surface);
  font-weight: 700;
  text-decoration: none;
}

.learning-index a:hover {
  border-color: var(--color-accent);
  color: var(--color-accent-strong);
}

.learning-module > section,
.content-body > section,
.callout,
[role="note"] {
  border: var(--border-thin) solid var(--color-border);
  border-inline-start: 0.3rem solid var(--color-accent);
  border-radius: var(--radius-small);
  padding: var(--space-4);
  background: var(--color-surface);
}

.learning-module > section h2,
.content-body > section h2 {
  font-size: var(--step-1);
}

.learning-module > section > :last-child,
.content-body > section > :last-child {
  margin-block-end: 0;
}

.learning-module > section:nth-of-type(6),
.learning-module > section:nth-of-type(8) {
  border-inline-start-color: var(--color-signal);
}

.learning-module > nav {
  justify-content: space-between;
  margin-block-start: var(--space-5);
  border-block: var(--border-thin) solid var(--color-border);
  padding-block: var(--space-3);
}

.learning-module > nav[aria-label="Level pembelajaran"] {
  justify-content: flex-start;
  margin-block-start: var(--space-3);
  border-block: 0;
}

.glossary {
  background:
    linear-gradient(90deg, var(--color-halo), transparent 70%),
    var(--color-surface) !important;
}

.glossary a {
  margin: 0.2rem;
  border: var(--border-thin) solid var(--color-border);
  border-radius: 999px;
  padding-inline: 0.75rem;
  text-decoration: none;
}

.go-deeper {
  margin-block: var(--space-5);
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-block: var(--space-4);
  background: var(--color-surface);
  font-size: var(--step--1);
}

caption {
  margin-block-end: var(--space-2);
  color: var(--color-text-muted);
  font-weight: 700;
  text-align: start;
}

th,
td {
  border: var(--border-thin) solid var(--color-border);
  padding: 0.8rem;
  text-align: start;
  vertical-align: top;
}

th {
  color: var(--color-accent-ink);
  background: var(--color-accent);
}

tbody tr:nth-child(even) {
  background: var(--color-canvas-raised);
}

@media (max-width: 40rem) {
  .site-header [data-nav-toggle] {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .site-brand span {
    display: none;
  }

  main > section nav[aria-label="Pilih level pembelajaran"] {
    grid-template-columns: 1fr;
  }

  main > section nav[aria-label="Pilih level pembelajaran"] a {
    min-height: 8rem;
  }

  table {
    display: block;
    max-width: 100%;
    overflow-x: auto;
  }
}