My note to myself : Dissapearing Firefox Caret (Cursor) CSS Fix

In FireFox (or any other Mozilla/Gecko based browser), the caret in input fields and textareas sometimes just disappears (viz. it’s not there). To be more precise it has something to do with input fields and textareas inside fixed-positioned elements. Found a CSS fix a few months ago, but forgot about it, so sticking a post-it …