Am I defining custom CSS wrong?

Hello,

I’m trying to set a custom CSS style on Neve. My custom style is not being recognized. I really don’t know why…

What I have:

When I do the following at “custom css” of Neve:

h2 {
  background-color: red !important;
}

I got a red background.

But when I do:

dwarf123 {
  background-color: red !important;
}

and set on the page dwarf123 as an additional css style, nothing happens. But on the page source, it contains

<h2 class="alignfull has-text-align-right dwarf123">Lipsum</h2>

What am I missing?

Thanks!!!!