Do nothing for me.

Firefox 128.

Try Evernote Web #en-note

Your UserCSS must specifically target the elements within the Shadow DOM. This script doesn't do that for you.

Of course, I tried

#en-note:host
{
padding: 0 !important;
background: red !important;
}



With and without :host

Is it works for you in Evernote Web?

Ops but now I can style inside shadow DOM without a userscript...