This technique will not work for browsers IE6 and older, but rather safely and cleanly degrades to default styling for those select boxes.

Have a drop down select box with a number of options ... what you are looking for cross-browser / platform in pure CSS. I personally usually only style inputs, textareas & buttons in forms ...

Now [Andy Green] has extended the possibilities with affordable silicon, by producing a proof-of-concept HTML + CSS renderer over h2 on ESP32 for libwebsockets. Surf the web on a microcontroller ...