<div id="overall-background"></div>
<main>
  <div class="container">
    <div id="background">
      <span class="reminder">
        use firefox to check!
      </span>
    </div>
    <p class="para">This is p element using <code>#background</code> as background.</p>
  </div>

</main>

#background {
  height: 200px;
  display: grid;
  place-items: center;
  background-color: var(--color-strawberry-foam);
  border-radius: var(--border-radius);
  box-shadow: 0 0 10px var(--color-indie-go);
}

.reminder {
  text-transform: uppercase;
  text-align: center;
  margin: 0;
  color: var(--color-indie-go);
  font-weight: 600;

  @supports (background: -moz-element(#background)) {
    display: none;
  }
}

.para {
  text-align: center;
  background: center -moz-element(#background);
}