Disclosure

Progressive drill-down built on the native <details> / <summary> element — open and close it with no JavaScript, full keyboard support for free. Casca only styles the marker, summary, and body; the browser does the rest, so it degrades to an always-open block in ancient engines.

Regional breakdown
North42%
South28%
West18%
East12%
 
<details class="casca-disclosure">
  <summary class="casca-disclosure-summary">Regional breakdown</summary>
  <div class="casca-disclosure-body">
    <table class="casca-data" ...> ... </table>
  </div>
</details>