.site-shell {
  display: grid;
  grid-template-columns: var(--sidebar-width) 1fr;
  min-height: 100vh;
}

.site-sidebar {
  border-right: 1px solid var(--line);
  background: rgba(9, 13, 26, 0.96);
  position: sticky;
  top: 0;
  height: 100vh;
  overflow-y: auto;
  padding: var(--space-5);
}

.site-main-wrap {
  min-width: 0;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: var(--header-height);
  padding: 0 var(--space-5);
  border-bottom: 1px solid var(--line);
  background: rgba(11, 16, 32, 0.88);
  backdrop-filter: blur(10px);
}

.site-main {
  width: min(100%, var(--max-content));
  margin: 0 auto;
  padding: var(--space-6);
}

.site-footer {
  width: min(100%, var(--max-content));
  margin: 0 auto;
  padding: var(--space-6);
  color: var(--text-3);
}

.hero,
.content-section {
  margin-bottom: var(--space-7);
}

.hero-home {
  display: grid;
  grid-template-columns: 1.3fr 0.9fr;
  gap: var(--space-6);
  align-items: stretch;
}

.section-heading {
  margin-bottom: var(--space-5);
}

.card-grid {
  display: grid;
  gap: var(--space-5);
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.card-grid-3 {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.simulation-stack {
  display: grid;
  gap: var(--space-5);
}

.prev-next-nav {
  display: flex;
  justify-content: space-between;
  gap: var(--space-4);
  margin-top: var(--space-7);
}

@media (max-width: 980px) {
  .site-shell {
    grid-template-columns: 1fr;
  }

  .site-sidebar {
    position: static;
    height: auto;
    border-right: 0;
    border-bottom: 1px solid var(--line);
  }

  .hero-home,
  .card-grid,
  .card-grid-3 {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 640px) {
  .site-main,
  .site-footer,
  .site-header,
  .site-sidebar {
    padding-left: var(--space-4);
    padding-right: var(--space-4);
  }

  .prev-next-nav {
    flex-direction: column;
  }
}
.nav-group-summary {
  margin: 0.35rem 0 0.6rem 0;
  color: var(--text-3);
  font-size: 0.9rem;
  line-height: 1.4;
}