.validate-form .form-control:required,
.validate-form .form-control:invalid
{
    border-left: 3px solid;
    transition: border-color .5s ease-out;
}
.validate-form .form-control:required
{
    border-left-color: #98fb98;
}
.validate-form .form-control:invalid
{
    border-left-color: #fa8072;
}