Unibody Windows Style Support

[hpr1999]

Hey there, this theme is absolutely beautiful!

I'm not sure what system you're developing on, but I've noticed it looks like the theme isn't tested with the Windows Unibody style. When this is enabled, the left menu looks like this:

It looks like the CSS-classes responsible for that styling start with .megamenu. Is there any way you could make an update for that?

I've tried tinkering with it, but you definitely have a talent for design that I don't :-)

Adding the following to fluent.css fixes the biggest problem.

.megamenu-content, .megamenu-opened header {
    background: var(--elevated-background);
}

The menu then looks like this:

The "recently opened documents" seem to lie within the div #recent-file-panel, but I haven't really succeeded in making that look nice.

Apart from that, I've only found one more thing:

Thanks for the great theme - it would be wonderful if you found the time to patch this!

P.S.: Relatively many themes don't support the Windows-Unibody style quite right, but themes like Panda do.