Inner Page Banner

Dear developers,

I would need some advice. Our page has too large image for Inner page banner, e.g. https://napocatku.cz/programy-pro-skoly/
Is it possible via CSS editor to reduce the maximum height of such images? I tried to do

.innerbanner img {
	max-height: 50% !important;
	width: auto !important;
}

But it does not help for most pages, only here https://napocatku.cz/domov/ (for the default Inner Page Banner), but not in the case the user choose a different Featured image.