/* Recreate Bootstrap 4 `.card-columns` (removed in Bootstrap 5) with the same
   CSS column masonry it used internally. entry.css forces a single column at
   <= 800px, exactly as on the original site. */
.card-columns {
  column-count: 3;
  column-gap: 1.25rem;
  orphans: 1;
  widows: 1;
}
.card-columns .card {
  display: inline-block;
  width: 100%;
  margin-bottom: 0.75rem;
}

/* Bootstrap 5 renamed the tooltip arrow element; keep it hidden as before. */
.tooltip .tooltip-arrow { display: none; }

/* Issue #18: on hover the description tooltip could appear under the cursor, causing
   it to flicker and block clicks on the link (Chrome). Making the tooltip transparent
   to the pointer stops the flicker and lets clicks reach the link underneath. */
.tooltip { pointer-events: none; }

/* KaTeX sizing — starting point; calibrate against the old MathJax `scale: 90`
   during screenshot verification. */
.katex { font-size: 1em; }