content: If you're talking about a dark theme, you can either force it through the browser settings or go into your computer's settings and put "prefer dark" and it'll change it for at least Chrome. Here's how you do that in Win 10: https://youtu.be/DRUl6YwT44c?t=75 In Firefox, you'll have to change the theme manually in the "Add-ons" menu. They have a built-in dark theme or you can download one.