background size 100 width code example
Example 1: background image size css
#example1 {
background: url(mountain.jpg);
background-repeat: no-repeat;
background-size: auto;
}
#example2 {
background: url(mountain.jpg);
background-repeat: no-repeat;
background-size: 300px 100px;
}
Example 2: how to set background automatically with my screen height
body {
background-image: url("img_tree.gif");
background-repeat: no-repeat;
background-attachment: fixed;
background-position: top center;
background-size: contain;
}