Как связать CSS с HTML
<link rel="stylesheet" href="styles.css">
Unusual Unicorn
<link rel="stylesheet" href="styles.css">
<head>
<link rel="stylesheet" href="styles.css">
</head>
<head>
<!-- Linking external Css document -->
<link rel="stylesheet" href="styles.css">
<!-- Writing Css inside HTML element -->
<style>
...
</style>
</head>
<link rel="stylesheet" href="PathToYourFile.css">
<p style="color: blue; font-size: 46px;">
// You can pass mutliple links into the urls using an array as well
browser.windows.create({url: "google.com"});