Example CSS Media Queries

@media only screen and (max-width: 600px) {
  body {
    background-color: lightblue;
  }
}
@media screen and (max-width: 600px) {
  div.example {
    display: none;
  }
}
@media screen and (min-width: 400px) {
  body {
    background-color: lightgreen;
  }
}

@media screen and (min-width: 800px) {
  body {
    background-color: lavender;
  }
}

<link rel="stylesheet" media="screen and (min-width: 900px)" href="widescreen.css">
<link rel="stylesheet" media="screen and (max-width: 600px)" href="smallscreen.css">