Awesome! It worked with the assistance of the support from the theme, they said this,
Please remove the code from custom.css, And add the following code to Custom Style Box:
.ui-dialog .ui-dialog-titlebar-close span {
display: block;
margin: -8px !important;
}
P.S: margin: none; doesn’t work if you want to remove margin, do this instead:
margin: 0px;
Thanks!
Daniel