add default styles for validating form elements, for browsers that have no default style. check out http://getbootstrap.com/docs/4.1/components/forms/#browser-defaults in different browsers to see how they are treated differently. make use of :required, :invalid, and :valid pseudo-classes.
add default styles for validating form elements, for browsers that have no default style. check out http://getbootstrap.com/docs/4.1/components/forms/#browser-defaults in different browsers to see how they are treated differently. make use of
:required
,:invalid
, and:valid
pseudo-classes.Browser support: https://caniuse.com/#feat=form-validation