form{
    position: relative;
}
.form__success{
    position: absolute;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 2;
    text-align: center;
    -webkit-transition-duration: 0.25s;
    -moz-transition-duration: 0.25s;
    -ms-transition-duration: 0.25s;
    -o-transition-duration: 0.25s;
    transition-duration: 0.25s;
    background: #fff;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
    visibility: hidden;
    opacity: 0;
}
.form__success.open{
    visibility: visible;
    opacity: 1;
}
.form-main__input.error{
    border-color: red;
}