<!DOCTYPE html>
<link rel="help" href="https://drafts.csswg.org/css-values-5/#attr-notation">
<link rel="match" href="../../../../expected/wpt-import/css/css-values/attr-notype-fallback-ref.html">
<style>
  #one::after {
    content: attr(does-not-exist, "Fallback value");
  }

  #two::after {
    content: attr(does-exist, "Fallback value");
  }

  #three::after {
    content: attr(does-not-exist, invalid);
  }

  #four::after {
    content: attr(does-exist, invalid);
  }

  #five::after {
    content: attr