.errorMessage {
    position: fixed;
    right: 10px;
    top: 10px;
    z-index: 2000;
}

@media screen and (min-width: 800px) {
    .errorMessage {
        width: 400px;
    }
}
@media screen and (max-width: 799px) {
    .errorMessage {
        width: 100%;
    }
}