html

<output></output> <output></output>

css

output {
  display: block;
}

@layer special {
  div {
    color: rebeccapurple;
  }
}

@layer {
  div {
    color: black;
  }
}

js

const item1 = document.getElementsByTagName("output")[0];
const item2 = document.getElementsByTagName("output")[1];
const rules = document.styleSheets[1].cssRules;
// Note that stylesheet #1 is the stylesheet associated with this embedded example,
// while stylesheet #0 is the stylesheet associated with the whole MDN page

const layer = rules[1]; // A CSSLayerBlockRule
const anonymous = rules[2]; // An anonymous CSSLayerBlockRule

item1.textContent = `The first CSSLayerBlockRule defines the "${layer.name}" layer.`;
item2.textContent = `A second CSSLayerBlockRule defines a layer with the following name: "${anonymous.name}".`;