dear friends,
I do not understand why I see the background image to fit to page with Chrome/Firefox on PC, while it does not fit on the default browser of a Galaxy Tab 3.
Please any help?
Thanky very much

Code:
<!DOCTYPE html>
<html>
<head>
    <link href="css/stili.css" rel="stylesheet" type="text/css">

    <style type="text/css">
        body {background-image: url('images/sfondo1.jpg')}

        @media screen and (orientation: portrait) 
        {
            #menu {width:130px;font-size: 20px;}
            #menu li a {line-height: 44px;}
            .Titolo {font-size: 20px;margin-left: 130px;}
            .Contenuti {font-size: 20px;margin-left: 130px;}
            .Riquadro {font-size: 20px;}
        }
    </style>
</head>
<body>

    <div class="Contenitore">
        <div class="Contenuti">
           testo.....
        </div>
    </div>
</body>
</html>
Code:
* {
    margin:0;
    border:0;
    padding:0;
}

html,body
{
    width:100%;
    height: 100%;
    background-color:transparent;
    color:rgb(0,0,0);
}

body
{
    background-repeat: no-repeat;
    background-position: 0 0;
    background-attachment:fixed ;
    -moz-background-size: cover;
    -webkit-background-size: cover;
    -o-background-size: cover;
    background-size: cover;
    z-index: 0;
}

.Contenitore
{
    width:100%;
    height: 100%;
    position:relative;
    top:0;
    left:0;
    overflow:auto;
    text-align:justify;
    z-index:10;
}

.Contenuti
{
    position:relative;
    font-family: Verdana, Geneva, sans-serif;
    font-size: 14px;
    padding-top: 30px;
    padding-bottom: 30px;
    padding-left: 30px;
    padding-right: 30px;
    margin-left: 100px;
    margin-right: 10%;
    background-color: rgba(255,255,255,0.6);
    box-shadow: 0px 0px 10px #2E2E2E;
    -webkit-box-shadow: 5px 5px 10px #333333;
    -moz-box-shadow: 5px 5px 10px #333333;
    overflow:auto;
}