How to fix html element on top against scrolling?

In under env given by phx.gen.live, I added the attribute, class=“sticky top-0” on index.heex’s elements, expecting the html element to be fixed on top against scrolling, but, it didn’t work, fail in fixing its position to top.

If I add it on layout, in app.heex whatever, it works.

My hypothesis is that tailwindcss somehow fails to attach css property when it is placed on slot of heex element.

How can I solve this?

I solved this; The overflow hidden attr was culprit.