Underline all links in posts and pages

To ensure all links in posts and pages are underlined, add this:

/* underline all links in posts and pages*/
#main a:link, a:visited{
text-decoration: underline;
}

To ensure that buttons are not underlined, add this:

.fusion button {
text-decoration:none!important;
}

You do this by adding these lines in Avada Theme Options > Custom CSS and pressing save.