body {
    margin: 0;
}

h1, p {
    margin: 0.35em;
}

ul {
    font-size: 1.5em;
    text-align: left;
    list-style-type: none;
    margin: 0;
    padding: 0;
    width: 17%;
    background-color: #f1f1f1;
    position: fixed;
    height: 100%;
    overflow: auto;
}

li a {
    display: block;
    color: #000;
    padding: 8px 16px;
    text-decoration: none;
}

li a.active {
    background-color: #3684e0;
    color: white;
}

li a:hover:not(.active) {
    background-color: #555;
    color: white;
}

#mainContainer {
    position: fixed;
    margin-left: 17%;
    height: 100%;
    width: 81%;
    padding: 1%;
    font-size: 1.5em;
    text-align: center;
    overflow: auto;
}

.embed-container {
    margin-top: 1%;
    margin-left: 12.5%;
    position: relative;
    padding-bottom: 46%; /* ratio 16x9 */
    height: 0;
    overflow: hidden;
    max-width: 75%;
    height: auto;
}

.embed-container iframe {
    z-index: 1;
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

#loadingDiv {
    z-index: 3;
    position: absolute;
    background-color: #6a8db5;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    color: aliceblue;
    padding-top: 28%;
}


button {
    background-color: #3684e0;
    border: none;
    color: #ffffff;
    font-size: 1em;
    padding: 0.5em 1.5em;
}

button:active {
    background: #ffffff;
    color: #3684e0;
}

button:focus {
    outline:0;
}

[title~="selected"] {
    background: #a8c7eb;
}