Hi Robert,
Add below custom CSS code to have the CTA button as you are asking for:
input[type="reset"],
input[type="button"],
input[type="submit"],
a.readmore,
.widget_custom-tagcloud a:hover,
#wp_page_numbers ul li a:hover,
#wp_page_numbers ul li.active_page a,
.wp-pagenavi .current,
.wp-pagenavi a:hover,
ul.default-wp-page li a:hover,
.pagination span,
.call-to-action,
.back-to-top a:hover,
#bbpress-forums button {
background-color: transparent;
}
.call-to-action {
border: 1px solid #000;
color: #000;
}
.call-to-action:hover {
background-color: #000;
color: #fff;
}
Thank you!