body{

  min-height: 100%;

  background: red;

}

​

/* the or in the next line can only be an "or" and not a "," */

@supports (display: block) or (display: inline) {

  body{

    background: blue;

  }

}

​

/* the comma in the next line can only be "," not "or" */

@media (max-width: 300px),  (min-width: 400px) {

  body{

    background: black;  

  }

}