body, html{
    background-color: #21242D;
    margin: 0px;
    height: 100%;
    width: 100%;
}


header {
    width: 100%;
    position: sticky;
}

#header-image {
    background-color: #333842;
    width: 100px;
    height: 100px;
    float: left;
    padding: 25px;
}

#header-text {
    background-color: #333842;
    overflow: auto;
    line-height: 40px;
    font-family: 'Segoe UI';
    color: #C0C0C0;
    font-size: 30px;
    padding: 25px;
}




nav {
    width: 100%;
}

#menu-ul {
    width: 100%;
    height: 50px;
    padding: 0;
    margin: 0;
    list-style: none;
}

#menu-li a {
    display: block;
    float: left;
    text-align: center;
    font-family: 'Segoe UI';
    margin-right: 0.05%;
    margin-left: 0.05%;
    font-size: 20px;
    width: 24.9%;
    line-height: 50px;
    text-decoration: none;
    color: #C0C0C0;
    background-color: #2e313b;
}

#menu-li a:hover {
    color: #C0C0C0;
    background: #333842;
}



section {
    width: 100%;
}

iframe {
    float: left;
    width: 100%;
    border: none;
    height: calc(100% - 220px);
    overflow: scroll;
    position: absolute;
}