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                <h1 id="h1">Does This Browser Support @layer?</h1>

  Layers are supported in all modern browsers!

  To get a more extensive overview of support in your current browser,
  see the
  <a href="">Web Platform Tests</a>.
  Scroll down the list to find all the <code>layer-*</code> tests.

  Layers allow you to manage the cascade more explicitly,
  specifying exactly what stlyes override other styles,
  without worrying about specificity or source order.
  For example, we can ensure that a <code>error</code> state
  always takes priority over other styles:

<button class='error' id='call-to-action'>example</button>


                /* It's a good practice to establish layer-order up-front */
/* Each layer overrides previous layers */
@layer default, component, state;

/* layers test */
@layer default {
  h1 {
    color: green;

  h1::before {
    content: "✅ ";

@layer state {
  button.error {
    border-color: maroon;
    background: red;

@layer component {
  #call-to-action {
    background: navy;
    color: white;
    border: medium solid navy;
    padding: 0.5em 1em;

/* for readability */
html {
  font-size: clamp(1em, 1em + 0.5vw, 2em);

body {
  margin: 0 auto;
  padding: 1em;
  max-width: 75ch;