The outline is not placed correct on inline-elements in Firefox. There is a space between background and outline.
Any suggestions to avoid that?
strong
{
background: #3690f0;
color: white;
outline: 1px solid black;
}
Firefox has a bug in drawing outline (see more here: https://bugzilla.mozilla.org/show_bug.cgi?id=480888). You can workaround utilizing box-shadow:
strong
{
background: #3690f0;
color: white;
box-shadow: 0px 0px 0px 1px rgba(0,0,0,1);
}