Request: Joplin Layout | css or redesign?

You can use the development tools to find the css element names.

See this post.

I haven’t modified my userchrome.css but if you want to change the colour, weight etc. of all the headers in the Markdown (#, ##, ### etc.) it looks like you would need to add something like:

.ace_heading {
	color: red;
	font-weight: bold;
}

to your userchrome.css.