This site has a dark mode and a light one. Which mode you see depends on the setting of your device. Try it! The instant change in appearance is accomplished by this appendix to the style sheet: @media (prefers-color-scheme: dark) { body { background-color: #444; color: #e4e4e4; } a { color: #e39777; } img { filter: grayscale(30%); } } This works in Firefox, Safari, and Chrome among other browsers