Ways to style a post?

I’m editing the FAQ of my site and I’m wondering to what extent the composer can be used to style it beyond what’s in the bbcode plug-in.

For example, what if I wanted my FAQ to be “accordion style,” where below each heading there is a dropdown which reveals more info? I know in some forums there is [accordion][/accordion] in bbcode.

In addition, can HTML still be used to style a post? According to this post that’s not the case anymore.

So am I limited to just the basis of color/size etc from the bbcode plugin?