input[type=submit] style issue with plug-in

This issue has been reported by another user previously, however no resolution seemed to be given.

In stm_lms.css the following section causes issues with any input[type=submit] element on any page on the site – even those not relevant to, or used by, the MasterStudy pages.

body:not(.masterstudy-theme):not(.theme-smarty):not(.theme-consulting):not(.theme-betop) .site .button:not(:hover):not(:active):not(.has-background), body:not(.masterstudy-theme):not(.theme-smarty):not(.theme-consulting):not(.theme-betop) .wp-block-button .wp-block-button__link:not(:hover):not(:active):not(.has-background), body:not(.masterstudy-theme):not(.theme-smarty):not(.theme-consulting):not(.theme-betop) .wp-block-file a.wp-block-file__button:not(:hover):not(:active):not(.has-background), body:not(.masterstudy-theme):not(.theme-smarty):not(.theme-consulting):not(.theme-betop) .wp-block-search .wp-block-search__button:not(:hover):not(:active):not(.has-background), body:not(.masterstudy-theme):not(.theme-smarty):not(.theme-consulting):not(.theme-betop) button:not(:hover):not(:active):not(.has-background), body:not(.masterstudy-theme):not(.theme-smarty):not(.theme-consulting):not(.theme-betop) input[type=reset]:not(:hover):not(:active):not(.has-background), body:not(.masterstudy-theme):not(.theme-smarty):not(.theme-consulting):not(.theme-betop) input[type=submit]:not(:hover):not(:active):not(.has-background) {
background: 0 0;
}

In the page link provided, the login button (to the left of the register button) remains invisible unless the mouse cursor is hovered over the button. In this case, the login functionality is from the Ultimate Member plugin, however the same issue occurs with submit buttons with the Contact Form 7 plugin – both very popular.

In browser developer tools, if I disable this rule, the problem goes away. As a work-around I have tried adding the “has-background” class to affected elements. While it works, this is not a particularly neat workaround, and is not possible in all cases.

I would have thought that the CSS rule should only be applicable to input[type=submit] page elements from the MasterStudy plugin only. It should not be affecting elements from other plugins or parts of the site.

Can you provide a response please? As indicated earlier, it’s not always possible for me to implement a work-around.

The page I need help with: [log in to see the link]