.main-content {
  flex: 1;
  padding: 1.75rem 2rem;
  overflow: hidden;
  min-width: 0;
}
.page-header {
  margin-bottom: 1.5rem;
  padding-bottom: 0.9rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  flex-wrap: wrap;
}
.page-header h1 { margin: 0; }
.page-header .subtitle { color: var(--text-muted); font-size: 0.85rem; }

/* Floating control to reopen the nav; only shown once it is collapsed, so it
   never sits in the content flow while the sidebar is visible. */
.sidebar-expand {
  position: fixed;
  bottom: 0.6rem;
  left: 0.6rem;
  z-index: 50;
  display: none;
  padding: 0.3rem 0.55rem;
  background: var(--sidebar-bg);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  font-size: 1.1rem;
  line-height: 1;
  cursor: pointer;
  box-shadow: var(--shadow);
}
.sidebar-expand:hover { background: var(--bg-hl); color: var(--text); }
html.sidebar-collapsed .sidebar-expand { display: block; }