.page {
  width: min(1260px, 96vw);
  margin: 0 auto;
  padding: 2.4rem clamp(1rem, 4vw, 2.6rem);
  display: grid;
  gap: 2.2rem;
}

.masthead {
  display: grid;
  gap: 1rem;
  padding: 1.6rem clamp(1rem, 3vw, 2.2rem);
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--surface);
  box-shadow: none;
}

.masthead__row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1.2rem;
  flex-wrap: wrap;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 1rem;
}

.brand__mark {
  width: 2.6rem;
  height: 2.6rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 600;
  letter-spacing: 0.04em;
}

.brand__text h1 {
  margin: 0;
  font-size: clamp(1.45rem, 3vw, 2rem);
  letter-spacing: -0.01em;
}

.brand__text p {
  margin: 0.3rem 0 0;
  color: var(--muted);
  font-size: 0.95rem;
}

.primary-nav {
  display: block;
}

.primary-nav__list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

.primary-nav__item {
  flex: 0 0 auto;
}

.primary-nav__link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.45rem 0.9rem;
  border-radius: 999px;
  border: 1px solid transparent;
  color: var(--muted);
  font-size: 0.88rem;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  transition: color 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}

.primary-nav__link::before {
  content: ">";
  font-size: 0.8rem;
  color: inherit;
}

.primary-nav__link:hover,
.primary-nav__link:focus-visible {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--accent-soft);
  outline: none;
}

.primary-nav__link.is-active {
  color: var(--fg);
  border-color: var(--accent);
  background: var(--accent-soft);
}

.masthead__summary {
  margin: 0;
  color: var(--muted);
  font-size: 0.98rem;
  line-height: 1.6;
  max-width: 68ch;
}

.layout {
  display: grid;
  gap: 1.8rem;
}

.content-shell {
  display: grid;
  gap: 1.2rem;
}

.page-meta {
  padding: 1.4rem clamp(1rem, 2.5vw, 1.6rem);
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--surface);
  box-shadow: none;
  display: grid;
  gap: 0.6rem;
}

.page-meta h2 {
  margin: 0;
  font-size: clamp(1.45rem, 3.2vw, 1.9rem);
  letter-spacing: -0.01em;
}

.page-meta p {
  margin: 0;
  color: var(--muted);
  font-size: 0.98rem;
  line-height: 1.7;
}

.content {
  display: grid;
  gap: 1.2rem;
}

.module {
  border: 1px solid var(--border);
  border-radius: 12px;
  background: var(--surface);
  padding: 1.8rem clamp(1.2rem, 2.6vw, 2rem);
  display: grid;
  gap: 1.1rem;
}

.module--lead {
  background: var(--surface-solid);
}

.module__header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 0.8rem;
  flex-wrap: wrap;
}

.module__title {
  margin: 0;
  font-size: clamp(1.25rem, 2.8vw, 1.7rem);
  letter-spacing: -0.005em;
}

.module__body {
  display: grid;
  gap: 0.9rem;
}

.grid-stack {
  display: grid;
  gap: 0.9rem;
}

.cluster-group {
  display: grid;
  gap: 1rem;
}

.cluster {
  border-radius: 10px;
  border: 1px solid var(--border);
  padding: 1rem 1rem 0.9rem;
  background: var(--surface);
}

.cluster__header {
  margin-bottom: 0.55rem;
}

.cluster__title {
  margin: 0;
  font-size: 0.88rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--muted);
}

.cluster__body {
  display: grid;
  gap: 0.75rem;
}

.callout {
  border-left: 3px solid var(--accent);
  padding: 0.7rem 0.9rem;
  border-radius: 8px;
  background: var(--accent-soft);
  color: var(--fg);
  font-weight: 500;
}

.principles {
  margin: 0;
  padding-left: 1.15rem;
  display: grid;
  gap: 0.5rem;
}

.interest-list {
  margin: 0;
  padding-left: 1.15rem;
  display: grid;
  gap: 0.6rem;
}

.note {
  color: var(--muted);
  font-size: 0.92rem;
}

.data-table {
  overflow-x: auto;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--surface-solid);
}

table {
  border-collapse: collapse;
  width: 100%;
  min-width: 320px;
}

th,
td {
  padding: 0.8rem 0.9rem;
  border-bottom: 1px solid var(--border);
  text-align: left;
}

thead th {
  text-transform: uppercase;
  letter-spacing: 0.08em;
  font-size: 0.76rem;
  color: var(--muted);
}

tbody th {
  width: 34%;
  font-weight: 600;
  font-size: 0.9rem;
}

tbody tr:last-child th,
tbody tr:last-child td {
  border-bottom: none;
}

.toc-panel {
  position: sticky;
  top: 6rem;
  align-self: start;
}

.toc-card {
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--surface);
  padding: 1.1rem 1rem;
  display: grid;
  gap: 0.7rem;
}

.toc-card nav:empty {
  display: none;
}

.toc-card__title {
  margin: 0;
  color: var(--muted);
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

.toc-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0.32rem;
}

.toc-item a {
  display: block;
  padding: 0.38rem 0.5rem;
  border-radius: 6px;
  color: var(--muted);
  font-size: 0.9rem;
  transition: color 0.2s ease, background 0.2s ease;
}

.toc-item.depth-3 a {
  padding-left: 1.25rem;
  font-size: 0.82rem;
}

.toc-item a:hover,
.toc-item a:focus-visible,
.toc-item a.active {
  color: var(--accent);
  background: var(--accent-soft);
  outline: none;
}

.footer {
  text-align: center;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--surface);
  padding: 2.1rem clamp(1rem, 3vw, 2.1rem);
  display: grid;
  gap: 1rem;
}

.footer blockquote {
  margin: 0;
  font-size: 1.22rem;
  font-style: italic;
  color: var(--accent);
}

.footer__meta {
  margin: 0;
  color: var(--muted);
  font-size: 0.86rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
}

.footer__controls {
  display: flex;
  justify-content: center;
}

.chip-button {
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.45rem 1rem;
  background: transparent;
  color: var(--fg);
  font-size: 0.86rem;
  display: inline-flex;
  gap: 0.35rem;
  align-items: center;
  cursor: pointer;
  transition: background 0.2s ease, border-color 0.2s ease;
}

.chip-button:hover,
.chip-button:focus-visible {
  background: var(--accent-soft);
  border-color: var(--accent);
  outline: none;
}

.chip-button__icon {
  font-size: 0.95rem;
}

.chip-button__label {
  font-size: 0.82rem;
  letter-spacing: 0.04em;
}

.chip-button--mini {
  padding: 0.35rem 0.8rem;
}

@media (min-width: 960px) {
  .layout {
    grid-template-columns: minmax(0, 1fr) 240px;
  }
}

@media (max-width: 900px) {
  .primary-nav__list {
    gap: 0.3rem;
  }

  .primary-nav__link {
    padding: 0.4rem 0.8rem;
    font-size: 0.82rem;
  }

  .layout {
    gap: 1.5rem;
  }

  .toc-panel {
    position: static;
  }
}

@media (max-width: 640px) {
  .page {
    padding: 1.6rem 1rem 2.2rem;
    gap: 1.6rem;
  }

  .masthead {
    padding: 1.3rem 1rem;
  }

  .page-meta {
    padding: 1.2rem 1rem;
  }

  .module {
    padding: 1.3rem 1rem;
  }

  .primary-nav__list {
    overflow-x: auto;
    padding-bottom: 0.2rem;
  }
}