html, body {
    width: 100%;
    height: 100%;
    padding: 0;
    margin: 0;
    font-family: Helvetica, Arial, sans-serif;
    position: relative;
    overflow: auto;
}
html { 
    background: url(../images/bg-image.jpg) no-repeat center center fixed; 
    -webkit-background-size: cover;
    -moz-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
}
div.inner_box {
    position: relative;
    width: 100%;
    height: 100%;
}
.pos_absolute {
    position: absolute;
}