html, body {
    width: 100%;
    height: 100%;
    margin: 0;
    padding: 0;
    overflow: hidden;
    background-image: url('kweb-bg01.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
    background-color: #1a1a1a;
}