Conflict With Another Plugin Over CSS

I have been using hestia theme with orfeo child theme, and ultimate member plugin. Ultimate Member provides its own design for forms, that looks good. But upon ultimate member, the plugin also provides its design for form. Ans Both conflict

You can see it yourself at https://milyin.com/login

Hestia provides its own code for form fields, and hestia combined with plugin’s css together really look bad
The theme has a horizontal line below the form field, that changes color when clicked, but the border on all 4 sides is the border of ultimate member. I want either or the 2.

Is there own any code, or class that i can add to ensure that hestia does not put its code on particular form fields,

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