/* Original detailed introduction plus a separate, all-expanded overview. */
.intro-toolbar { display:flex; align-items:center; justify-content:space-between; gap:24px; margin-bottom:52px; }
.intro-toolbar .breadcrumb,.intro-toolbar .reading-breadcrumb { margin-bottom:0; }
.intro-switch { display:flex; flex-shrink:0; gap:6px; padding:4px; border:1px solid #dedede; border-radius:999px; background:#f5f5f5; }
.intro-switch a { display:flex; align-items:center; justify-content:center; min-height:36px; padding:0 18px; border-radius:999px; font-size:14px; font-weight:650; color:#555; white-space:nowrap; }
.intro-switch a:hover { color:#111; background:#e7e7e7; }
.intro-switch a[aria-current=page] { background:var(--action-blue,#2563ed); color:#fff; }
.reading-hero .intro-toolbar { margin-bottom:0; }
.reading-hero .reading-intro { padding-top:48px; }
@media (max-width:1024px) {
  .intro-toolbar { margin-bottom:36px; }
}
@media (max-width:640px) {
  .intro-toolbar { align-items:flex-start; flex-direction:column; gap:20px; margin-bottom:32px; }
  .intro-switch { width:100%; }
  .intro-switch a { flex:1; padding:0 12px; min-height:40px; font-size:13px; }
  .reading-hero .reading-intro { padding-top:38px; }
}