How To Create Divi Fullwidth Contact Form Submit Button

user this CSS code:

/** Divi Contact form full-width submit button **/

body #page-container .et_pb_contact_form_0.et_pb_contact_form_container .et_pb_button {
width: 97%;
margin-left: 7px;
margin-top: 6px;
}
body #page-container .et_pb_contact_form_0 .et_contact_bottom_container {
width: 100%;
}

/** Divi Contact form full-width submit button for mobile **/
@media (max-width: 479px){
.et_contact_bottom_container {
width: 100%!important;
}
.et_pb_contact_submit {
width:100%!important;
}
}