I’ve been using HTML since tables were in vogue. I’ve come a long way since, but if you need an e-mail coded, I’ve still got tables down cold.
Can’t have HTML without CSS! I’m a big fan of SASS, too. Responsiveness is in my repertoire as well.
I can read it, I can write it, and I think libraries are a great tool in the proper circumstances.
Content management systems! I’m particularly adept at WordPress, but I’ve learned and worked in proprietary systems as well.
Other technical bits I’m familiar with: PHP, Ruby, & Ruby on Rails, plus whatever else I need to learn to get the job done!