I can make Firefox not display the ugly dotted focus outlines on links with this:
a:focus {
outline: none
There is many solutions found on the web for this, many of which work, but to force this, so that absolutely nothing can highlight/focus once a use the following:
::-moz-focus-inner, :active, :focus {
outline:none;
border:0;
-moz-outline-style: none;
}
This just adds that little bit extra security & seals the deal!