header {
    display: block;
    width: 100%;
    height: fit-content;
    background-color: #ffffffcc;
    padding: 10px 0px;
    /* position: sticky; */
    /* top: 0; */
    /* left: 0; */
    margin: 0;
    /* z-index: 999; */
    border-bottom: 1px solid #ddd;
}

.HeaderBar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 20px;

    .LogoutButton {
        border: 0;
        outline: 0;
        background-color: transparent;
        padding: 5px 7px;
        color: #999;
        font-size: 1.2em;
        transition: color 0.2s;
        cursor: pointer;
        text-decoration: none;
    }

    .LogoutButton:hover {
        color: #555;
    }
}