Hidden checkboxes in admin screens

I’m using a child theme with Responsive Mobile and I’ve come across an issue with checkboxes being hidden due to the css;

.js .checkbox, .js .checkbox-toggle {
/* display: none; */
}

This is located in the file /responsive-mobile/libraries/css/meta-box.css

This is causing a problem because SiteOrigin page builder uses checkboxes in a dialog overlay.

Can I remove this css, or overwrite it in my child theme? I’ve tried various ways to target this css without any luck yet.
Thanks