Minimal Genesis form styles.

style.css

input, 
textarea,
.nf-form-content .list-select-wrap .nf-field-element > div, 
.nf-form-content input:not([type=button]), 
.nf-form-content textarea,
.site-container .wpforms-container .wpforms-form .wpforms-field input, 
.site-container .wpforms-container .wpforms-form .wpforms-field textarea {
 	border: 0 !important;
 	border-bottom: 3px solid #eee !important;
}

input:focus, 
select:focus,
textarea:focus,
.nf-form-content .list-select-wrap .nf-field-element > div:focus, 
.nf-form-content input:not([type=button]):focus, 
.nf-form-content textarea:focus,
.site-container .wpforms-container .wpforms-form .wpforms-field input:focus , 
.site-container .wpforms-container .wpforms-form .wpforms-field textarea:focus {
 	border: 0 !important;
 	border-bottom: 3px solid #ddd !important;
 	outline: none !important;
}