background image fit size code example

Example 1: css background image fit

body {
    background-image:    url(images/background.svg);
    background-size:     cover;                      /* <------ */
    background-repeat:   no-repeat;
    background-position: center center;              /* optional, center the image */
}

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;

 }