*

css/style.css

* {
color: #F00;
}

* {
 color: #F00;
}

index.html

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>New Page</title>
<link href="css/style.css" rel="stylesheet" />
</head>
<body>
<h2>Hello World!</h2>
<h3>To be or not to be?</h3>
<h4>Привет Мир!</h4>
</body>
</html>

<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>New Page</title>
<link href="css/style.css" rel="stylesheet" />
</head>
<body>
<h2>Hello World!</h2>
<h3>To be or not to be?</h3>
<h4>Привет Мир!</h4>
</body>
</html>