body {
    background-color:gray;
    }
    * {
    font-family: Arial;
    }
    svg {
    position:absolute;
    }
    h2, h3 {
    text-align: center;
    }
    button {
    float: right;
    clear: both;
    cursor: pointer;
    width: 80px;
    margin: 8px;
    height: 30px;
    margin-right: 0px;
    font-weight: bold;
    background-color: black;
    color:white;
    }
    #controller {
    clear:both;
    float: right;
    color: white;
    background-color: black;
    width: 220px;
    height: 480px;
    border: 1px solid white;
    padding: 8px;
    }
    #number_result, #speed_result, #size_result, #width_result {
    font-size: 15px;
    text-align: center;
    }
    #whole {
    position: fixed;
    top: 50%;
    left: 50%; 
    margin-top:-480px;
    margin-left:-400px;
/*    width: 2000px;
    height: 2000px;*/
    }
    .slider {
    color: black;
    background-color: gray;
    font-size: 12px;
    border: 1px solid white;
    }