/* Shared "ANSWER KEY" banner. Purely additive: one extra <link> tag per
   tool, zero HTML/JS changes needed anywhere — works because every
   answer-key section across the whole suite already follows the same
   pattern: <section class="sheet answerkey-only"><header class="sheet-header">.
   Renders on screen, in print, and in PDF export (html2canvas renders
   ::before content), since answer-key sections are always in the DOM,
   just print-CSS-hidden depending on which print mode is selected. */

.answerkey-only .sheet-header::before {
  content: "✓ ANSWER KEY";
  display: inline-block;
  background: #b91c1c;
  color: #ffffff;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.05em;
  padding: 4px 12px;
  border-radius: 4px;
  margin-bottom: 10px;
}