404 page has poor visibility with new background image

[hexaflexahexagon]

See https://momentum-mod.org/asdfsd

[bakapear]

Put big stripe behind it maybe?

[hexaflexahexagon]

looks good to me. @Gocnak thoughts?

[Gocnak]

Fine with me, yep!

[glassglue]

I can do this in parallel with #356 - I imagine we want consistency between the various server messages

[glassglue]

This is what I have currently in dev - thoughts? If the gradient is a bit much that can be removed super easily, as we recently refactored how that displays.
Some resizing will be done, just to make sure everything is centered properly - should be a pretty close 1:1 of what's above