styles.css

html {
    box-sizing: border-box;
    font-size: 15px;
    font-family: Roboto, 'Helvetica Neue', sans-serif;
}
.videoChoice {
    cursor: pointer;
    height: 20px;
    width: 190px;
    border: 1px solid black;
    padding: 5px;
}
.videoChoice:hover {
    background-color: #bcf5bc;
}
.completedVideo:after {
    content:'\2713';
    display:inline-block;
    vertical-align: top;
    color:green;
    padding:0 6px 0 6px;
}
#noVideoMessage {
    font-size: 1.5em;
    width:488px;
    height:400px;
    border: 2px solid black;
    display: flex;
    align-items: center;
}
#noVideoMessage div {
    margin-left:80px;
    text-align:center
}
h4 {
    margin-bottom: 7px;
}
#videoChoices {
    display:flex;
    justify-content:space-between;
    width:700px;
    margin-bottom: 30px;
}
#videoChoices div div {
    margin-bottom: 10px;
}
#videoDiv {
    margin-left:100px;
}
#video {
    display:none;
}