/* Six activity tiles share equal columns; inner exercise tabs keep their layout. */
main nav.tabs{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));grid-auto-rows:1fr;gap:14px;width:100%;align-items:stretch}
main nav.tabs>.tab{width:100%;min-width:0;height:100%;min-height:76px;margin:0;white-space:normal;text-align:center;line-height:1.4;overflow-wrap:break-word}
@media(max-width:900px){main nav.tabs{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:650px){main nav.tabs{grid-template-columns:1fr}main nav.tabs>.tab{text-align:left}}