*{
    box-sizing: border-box;
}

body{
    background: #333;
    color: #fff;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    font-family: Arial, Helvetica, sans-serif;
    min-height: 100vh;
    margin: 0;
}

canvas{
    -moz-transition:background .5s ease-in;
    -o-transition:background .5s ease-in;
    -webkit-transition:background .5s ease-in;
    background: #a0a0a0;
    border-radius: 5px;
    border: 1px solid white;
}