Constant colors in embed.css

[Maxilver]

Hi!

Thanks for the widget, it's really good tool :)
I've noticed that some of styles in embed.css is using only constant color w/o var() from the theme.
E.g.

#modal_guildinfobox {
  background-color: #455a64;
  padding-top: 10px;
  padding-bottom: 10px;
}

Always will display Fiord color without regardless of the theme.

I guess it could be easily fixed by custom CSS, but would be awesome to cover const styles with relevant variables.

[Maxilver]

For #modal_guidinfobox I guess it should be --main

#modal_guildinfobox {
  background-color: #455a64;
  background-color: var(--main);
  padding-top: 10px;
  padding-bottom: 10px;
}

[Jeremy "EndenDragon" Zhang]

Thank you for the issue report! I've implemented the fix in 0ead122.