Hi, I recently discovered Just BASIC and Run BASIC. This original resource list was posted 6 years ago (now 2013).
As a new user of Run BASIC I haven't experimented with CSS3 / HTML5 embedded or generated using BASIC. I would like to be able to generate or embed valid HTML5 syntax, but that's off topic.
As a web developer I personally recommend that users learn HTML and CSS first, and then implement and customize their markup and styling for building something with RunBasic and the BASIC programming language.