background size in css code example

Example 1: how to cover full image in css

body {
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
}

Example 2: 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 3: 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;

 }

Example 4: how to change the width of a background image in css

#example1 {		/* Example1 has an auto background size */
  background: url(mountain.jpg);
  background-repeat: no-repeat;
  background-size: auto;
}

#example2 {		/* Example2 has an fixed background size */
  background: url(mountain.jpg);
  background-repeat: no-repeat;
  background-size: 300px 100px;
}