styles-source-lines-recovery-helper.html

<html>
<head>
<style>
@media all {
    ::-moz-focus-inner {}
}
#main {
    color: red;
}
</style>

<style>
@-webkit-region x {
    x ? {}
}
#main {
    color: blue;
}
</style>

<style>
@-webkit-region x {
    ? {}
}
#main {
    color: white;
}
</style>

</head>

<body>

<div id="main"></div>

</body>
</html>

chromium/third_party/blink/web_tests/http/tests/devtools/elements/styles-4/resources/styles-source-lines-recovery-helper.html