Okay, I actually think I figured it out (may need some adjustment - open to suggestions!). But for anyone searching:
I used this code -- a Code box on the column, and then just adjusted the top px.
Source: Will Myers
Add this to Custom CSS:
@media(min-width:767px) {
.col.wm-sticky-column {
position:sticky;
top: 150px;
}
}
Put this in a code box in the column you want (works for blog posts, even in fluid engine):
<div class="wm-sticky-column"></div>
<script>
(function() {
function initSticky() {
let stickyStarts = document.querySelectorAll('.wm-sticky-column');
stickyStarts.forEach(el => {
let col = el.closest('.col');
if (!col) return;
col.classList.add('wm-sticky-column');
});
}
window.addEventListener('DOMContentLoaded', initSticky);
}());
</script>