HTML5 match different resolution styles

. ABC{Height:300px;Border:1px solid #000;margin:0 Auto}@media screen and (min-width:1201px){. ABC {width:1200px}  } /*when the browser width is set not less than 1201PX, the ABC display 1200px width*/@media screen and (max-width:1200px){. ABC {width:900px}  } /*when the browser width is not more than 1200px, the ABC display 900px width*/@media screen and (max-width:900px){. ABC {width:200px;}  } /*when the browser width is not more than 900px, the ABC display 200px width*/@media screen and (max-width:500px){. ABC {width:100px;}  } /*when the browser width is not more than 500px, the ABC display 100px width*/ 

HTML5 match different resolution styles