extra.css/crossOut/style.css

body {
  font-family: monospace;
  height: 100vh;
  width: 100vw;
  text-align: center;
  padding: 0;
  margin: 0;
}

p {
  max-width: 660px;
  margin: 0 auto;
  font-weight: 300;
  font-size: 1.2rem;
  line-height: 1.5;
  text-align: left;
}

h1 {
  font-size: 4rem;
  display: inline-block;
  font-weight: 100;
  margin: 1rem auto;
  width: 100%;
  max-width: 760px;
  position: relative;
}

h2 {
  font-size: 2.5rem;
  font-weight: 100;
  display: inline-block;
  position: relative;
}

@supports (background: paint(something)) {
  h1 {
    /* 
      Optionally set property values. 
      This can be done at root or local scope 
    */
    --extra-crossColor: #fc0; /* default: black */
    --extra-crossWidth: 2; /* default: 1 */

    background: paint(extra-crossOut);
    line-height: 1.5;
  }

  h2 {
    margin: 10rem auto;
    display: block;
    width: 80vw;
    max-width: 900px;
    height: 400px;
    display: flex;
    justify-content: center;
    align-items: center;
  }

  h2:before {
    --extra-crossColor: #fa4; /* default: black */
    --extra-crossWidth: 30; /* default: 1 */
    content: '';
    width: 100%;
    height: 100%;
    display: block;
    position: absolute;
    left: 0;
    top: 0;
    z-index: -1;
    background: paint(extra-crossOut);
    transform: rotate(20deg);
    mix-blend-mode: lighten;
  }
  h2:after {
    --extra-crossColor: #b4f; /* default: black */
    --extra-crossWidth: 50; /* default: 1 */
    content: '';
    width: 100%;
    height: 100%;
    display: block;
    position: absolute;
    left: 0;
    top: 0;
    z-index: -2;
    background: paint(extra-crossOut);
    transform: rotate(-20deg)
  }

  span {
    --extra-crossColor: #d4f;/* default: black */
    --extra-crossSpread: 10; /* default: 100, which is 100% of the height of the element */

    background: paint(extra-crossOut);
  }
}