This is a collection of little tidbits regarding web development. They come from many years of coding, so some examples are quite dated. I hope that you find some useful stuff here.
Color Preference - Detect a light or dark theme using just CSS.
Favicon - A shortcut icon or favicon is a little image that shows up in the address bar of your browser. These instructions show how to set one.
Mouseover Example - Swapping images with a mouseover. This also displays textual descriptions and can put a message in the status bar.
Scoreboard - A sample scoreboard for a geocacher in my area.
Transparency - How to fade elements in and out. Complete with a live example and tips to avoid flickers in the browser.