Answer by iorgv for Unicode character for "X" cancel / close?

For CSS: just use the content: "\d7"; which is the × html entity, so it's widely supported on mobile devices as well.

.close:before {  content: "\d7";  font-size: 30px;  font-style: normal;}

<span class="close"></span>

For those who are looking for the most supported hamburger "icon" (3 lines):

content: "\2261"; which is the ≡ html entity.