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                <h1>Hello World</h1>
  <li>This text color is red between medium (960px) and small screen (768px)</li>
  <li>Become green when below extra small screen (480x)</li>
  <li>And have larger font size when below 300px</li>
<p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Quaerat mollitia laudantium minima reprehenderit</p>
<p>Laboriosam nulla inventore amet ratione deserunt delectus excepturi beatae omnis modi repudiandae molestias quo debitis quia ullam</p>
<p>Voluptas sit ab? In labore cumque accusantium, officiis eius iure quisquam eligendi dicta voluptatum adipisci perspiciatis repellat ipsam?</p>
<p>Eos dolore ex dolor exercitationem iusto, doloribus alias odit. Deserunt fugiat inventore quidem architecto repudiandae. Error harum in beatae nihil quasi, vel dolore odio blanditiis, doloribus ad adipisci.</p>
<p>Totam aspernatur accusamus. Quas sunt voluptatibus, tenetur aliquid quos quibusdam placeat laboriosam est earum! Quaerat laborum consectetur minus mollitia exercitationem velit tempora voluptatum quos!</p>


                // Extra Small (mobile)
$below-xs: "max-width:480px";
$above-xs: "min-width:481px";

// Small (tablet)
$below-s: "max-width:768px";
$above-s: "min-width:769px";

// Medium (landscape tablet)
$below-m: "max-width:960px";
$above-m: "min-width:961px";

// Large (content max-width)
$below-l: "max-width:1120px";
$above-l: "min-width:1121px";

$portrait: "orientation: portrait";
$landscape: "orientation: landscape";
$retina: "min-resolution: 192dpi";

@function below( $size-px ) {
  @return "max-width: #{$size-px}";

@function above( $size-px ) {
  @return "min-width: #{$size-px}";

// -------

body {
  color: black;
  @media ($above-s) and ($below-m) {
    color: red;

  @media ($below-xs) {
    color: green;
  @media (below(300px)) {
    font-size: 20px;