how to fit 100% background color in home page using css code example

Example 1: css background image cover center

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

Example 2: CSS make image fill whole background

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