I'm currently learning how to use markmap. I did use the linux cli with vim, it works great, but I'm unable to customize the appearance in details.

I found recently it is possible to use the auto-loader and edit directly my map in an html file. I understood that I can now use the <style> block to change things, like URL appearance for instance. But what I can't find, if it is possible to customize the headers style at the top without the need to configure it in each line.

For instance :

Level 1

Level 2

and transform with something like that:
<style>
markmap.h1 {
color: red ;
font-size: 1.5em ;
}
markmap.h2 {
color: blue ;
font-size: 1.25em ;
}
</style>

...

Level 1

Level 2

Any suggestions?