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;
}
.container canvas {
    display: block;
    margin: 0 auto;
    background-color: black;
}