.content-style .letterLinks a.btn {
    margin: 2px;
    padding-left: 0.5em;
    padding-right: 0.5em;
    font-weight: bold;
}

#directory-top-menu {
    position: sticky;
    top: 0;
    display: block;
    background-color: #fff;
    box-shadow: 0 0 10px 10px #fff;
}