input.wpcf7-form-control.wpcf7-submit:not([disabled]) {
    border: 2px solid #ffffff;
    color: #ffffff;
}
input.wpcf7-form-control.wpcf7-submit:not([disabled]):hover {
    background-color: #e31836;
    border-color: #e31836;
    color: #fff;
    text-decoration: none;
}