background attachment: fixed not working on android/ios

Question

This is my code:

Answer 1

Div cover (version 1):

HTML5:

CSS3:

.fixed { 
background: url(img/kid1/1.jpg) no-repeat center center fixed; 
-webkit-background-size: cover;
-moz-background-size: cover;
-o-background-size: cover;
background-size: cover;
}

OR:

Div cover (version 2):

HTML5:

CSS3:

.fixed {  
-webkit-background-size: cover;
-moz-background-size: cover;
-o-background-size: cover;
background-size: cover;
}

Or on "html" tag (fullscreen cover):

html { 
background: url(img/kid1/1.jpg) no-repeat center center fixed; 
-webkit-background-size: cover;
-moz-background-size: cover;
-o-background-size: cover;
background-size: cover;
}

Simple. :)