body {
    overflow: hidden;
}

div {
    margin-top: 10px;
}

.error {
    animation-duration: 0.5s;
    animation-name: popup;
    color: red;
}

@keyframes popup {
    from {
        margin-top: 20px;
        opacity: 0;
    }
    50% {
        opacity: 1;
    }
}

.error-hide {
    animation-duration: 0.5s;
    animation-name: popdown;
    color: red;
}

@keyframes popdown {
    to {
        margin-top: 20px;
        opacity: 0;
    }
}
.info {
    color: green;
}