chromium/src/third_party/blink/web_tests/fast/media/empty-media-rule.html

<style>
div { color: red }
</style>
<style>
@media;
#t1 { color: green; }
</style>
<style>
@media{}
#t2 { color: green; }
</style>

<p>Test that CSS parser stops parsing @media rule after a semicolon or a block.</p>

<div id=t1>Tests @media;. This text should be green.</div>
<div id=t2>Tests @media{}. This text should be green.</div>