body {
    margin: 0px;
    padding: 0px;
    display: flex;
    flex-direction: column;
}

#header {
    position: sticky;
    top: 0px;
    padding: 10px;
    background-color: white;
    box-shadow: 0px 0px 5px 5px black;
    transition: transform 0.5s;
}

#footer {
    margin-top: auto;
}

#header.hide {
    transform: translateY(-100%);
}