I found that after adding blank lines in HTML inline CSS, the HTML preview function failed to work, here is the sample code:
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Test</title>
<style>
/* Inline CSS */
.css1 { color : green; }
/* ADD BLANK LINE HERE */
.css2 { color : blue; }
</style>
</head>
<body>
<span class="css1">Statement1</span>
<span class="css2">Statement2</span>
</body>
</html>
Can you please confirm this ?