From Valve Developer Community
Use this to rein in the KV, I and O lists on entity pages.
Tip:If you've got a short ScrollBox containing a long one, set
noscroll=trueon the shorter of the pair to avoid having two scrollbars right next to each other.
Tip:If the scrollbar on your ScrollBox starts to get lost, set
bottom-border=trueto add a faint rule after it.