That's why it's not working - the files aren't where you say they are. These two lines are telling the browser that the separate files are in separate directories
<link rel="stylesheet" href="css/style.css">
You have two choices. The first would be to remove the folder directives for these two files
<link rel="stylesheet" href="style.css">
That will get you up and running quickly, but can be detrimental in the long run as your sites get more complex. It's better to get into the habit of separating your files into common folder structures for maintenance in the future. So (IMHO), the better approach would be to go into your desktop folder and create two folders inside it, one called css, and one called js. Next, move the styles.css folder into the css folder, and the scripts.js folder into the js folder.