document.querySelectorAll('.expanding-col').forEach(col => {
col.addEventListener('mouseenter', function() {
this.classList.add('expanded');
this.parentElement.querySelectorAll('.expanding-col').forEach(other => {
if (other !== this) other.classList.remove('expanded');
});
});
col.addEventListener('mouseleave', function() {
this.classList.remove('expanded');
});
});
