Question

I was wondering how can I keep my main parent category highlighted as when hovered on when viewing the main parents sub categories using CSS?

A quick example or tutorial will help thanks.

Answer 1

You can use the code from CSS play 1 or CSS play 2 for this.

Each of examples meets your needs.
Main idea is to use pseudo-class for the base class:

#menu li a:hover {border:0; text-decoration:underline;}
#menu li:hover dd, #menu li a:hover dd {display:block;}
#menu li:hover dl, #menu li a:hover dl {padding-bottom:15px;}
#menu li:hover dt a, #menu li a:hover dt a, #menu dd a:hover {color:#c00;}