.guide-shell {
  max-width: 1080px;
  margin: 0 auto;
  padding: 32px 20px 48px;
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: 40px;
  align-items: start;
}

.guide-index {
  position: sticky;
  top: 64px;
  background: #fff;
  border: 1px solid #e2e8f0;
  border-radius: 12px;
  padding: 14px 12px 16px;
}

.guide-index-title {
  display: block;
  font-size: 12px;
  font-weight: 600;
  color: #64748b;
  letter-spacing: 0.04em;
  margin: 0 8px 10px;
}

.guide-index-group {
  font-size: 11px;
  font-weight: 600;
  color: #94a3b8;
  margin: 12px 8px 4px;
}

.guide-index a {
  display: block;
  font-size: 13px;
  line-height: 1.4;
  color: #475569;
  text-decoration: none;
  padding: 6px 8px;
  border-radius: 8px;
}

.guide-index a:hover {
  background: #f8fafc;
  color: #4f46e5;
}

.guide-index a.is-current {
  background: #eef2ff;
  color: #4338ca;
  font-weight: 500;
}

.guide-main {
  min-width: 0;
}

@media (max-width: 860px) {
  .guide-shell {
    grid-template-columns: 1fr;
    padding-top: 20px;
  }
  .guide-index {
    position: static;
  }
  .guide-index-nav {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0 8px;
  }
}