Additional.css drama

[PattiOz]

My additional.css is not working consistently.

I am attempting to add this code into additional.css:

#posttree {
overflow: auto;
padding: 2px;
text-align: left;
border: 1px solid #C89D5B;
border-top: 0;
white-space: nowrap;
}

Which basically just removes the height restriction of the box (default is 150px) and changes the border to a different color in the threaded mode view.

I have already tried hard refresh, putting height: auto; there, nothing works.

What am I doing wrong?

Thanks for any help. I'm not a coder.