chromium/third_party/blink/web_tests/external/wpt/css/css-nesting/supports-rule.html

<!DOCTYPE html>
<title>@supports with nesting</title>
<link rel="author" title="Matthieu Dubet" href="mailto:[email protected]">
<link rel="help" href="https://drafts.csswg.org/css-nesting-1/">
<link rel="match" href="supports-rule-ref.html">
<style>
  .test {
    background-color: red;
    width: 100px;
    height: 100px;
    display: grid;
  }

  @supports(not selector(> .test-1)) {
    .test-1 {
      background-color: green;
    }
  }

  .test {
    > .test-2 {
      background-color: green;
    }
    @supports (selector(> .test-2)) {
      > .test-2 {
        background-color: red;
      }
    }
  }

  .test-3 {
    @supports (selector(&)) {
      & {
        background-color: green;
      }
    }
  }

  @supports(selector(&)) {
    .test-4 {
      background-color: green;
    }
  }

  body * + * {
    margin-top: 8px;
  }
</style>
<body>
  <p>Tests pass if <strong>block is green</strong></p>
  <div class="test test-1"></div>
  <div class="test"><div class="test-2"></div></div>
  <div class="test test-3"></div>
  <div class="test test-4"></div>
</body>