body {
    font-family: 'Roboto', sans-serif;
    padding: 0;
    margin: 0;
    -webkit-box-sizing: border-box;
       -moz-box-sizing: border-box;
            box-sizing: border-box;
}
.container {
    max-width: 1200px;
    margin: 40px auto;
    padding: 40px 20px;
    background-color: whitesmoke;
    justify-content: center;
}
header {
    padding: 0 0 30px 0;
    font-size: 30px;
}

.video-container{
    position: relative;
    width: 100%;
    padding-bottom: 56.25%; 
    height: 0;
}
.video-container iframe{
    position: absolute;
    top:0;
    left: 0;
    width: 100%;
    height: 100%;
}