.invalid-feedback {
    display: none;
    width: 100%;
    margin-top: .25rem;
    font-size: 80%;
    color: red;
}

.is-invalid+.invalid-feedback {
    display: block;
}

.berlesformcont {
    background: #f4f4f4;
    border-top: 5px solid #f1f1f1;
    padding: 30px;
}