html {
    -webkit-transition: background-color 1s;
    transition: background-color 1s;
}
html, body {

    min-height: 100%;
}
html.loading {
 
    background: #fff url('images/loader.gif') no-repeat 50% 50%;

    -webkit-transition: background-color 0;
    transition: background-color 0;
}
body {
    -webkit-transition: opacity 1s ease-in;
    transition: opacity 1s ease-in;
}
html.loading body {

    opacity: 0;
    -webkit-transition: opacity 0;
    transition: opacity 0;
}