* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
main {
    display: block;
    position: relative;
}
#canvas {
    width: 100vw;
    height: 100vh;
}
.link {
    position: absolute;
    right: 20px;
    bottom: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    width: 50px;
    height: 50px;
    text-decoration: none;
    background-color: #fff;
    border-radius: 50%;
}
.link::before {
    content: '</>';
    display: block;
    color: dodgerblue;
    font-size: 20px;
}