/* 99 Club Studio · Corner/Linked Sum Grid polish v1.48 */
/* Force true 3 × 3 square geometry in both printable preview and Online Play. */
.tt99-sumgrid-board,
.tt99-play-sumgrid .tt99-numbergrid{
  grid-template-columns:repeat(3,minmax(0,1fr))!important;
  grid-template-rows:repeat(3,minmax(0,1fr))!important;
}
.tt99-sumgrid-cell,
.tt99-play-sumgrid .tt99-numbergrid-cell{
  min-width:0!important;
  min-height:0!important;
}
/* Keep A/B/C labels away from the four internal sum circles. */
.tt99-sumgrid-letter,
.tt99-play-group-letter{
  left:50%!important;
  right:auto!important;
  top:5px!important;
  transform:translateX(-50%)!important;
  z-index:5!important;
}