How to make a combo box overlay other items?

Question

HTML

Hello everyone!
For dropdown lists, I use Select2 , everything is good, great and convenient.
But there is a small bug (feature?) that I can't fix. The dropdown list stubbornly refuses to overlap other elements. Those. for example:

The dropdown part does not overlap the button. How can this be fixed?

Answer 1

Look towards the CSS 'z-index' property - the button should have it less than the list.

Answer 2

If everything is ok with z-index, apparently the drop-down list has no background and the button is visible through it. Make background: #fff;