How to apply CSS hover correctly?

Question

css

Site test06.menchasha.ru/. I'm trying to implement a CSS hover effect so that when you click on a link (Promotional Activities), a ul appears on the right.
I use the code:
.child {
visibility: hidden;
}
a .title1:hover + .child {
visibility: visible;
}
Ul disappears, but when hovering over the link on the left, it does not appear.

Thank you in advance!

Answer 1

I'm trying to implement a CSS hover effect so that when you click on a link

Hover is not a click, but a hover.
You can do something like this:
https://codepen.io/elijah_tr/pen/mXPPVx
there and :hover and toggle on click.