Remove 'cloud assignment' from the top bar Canvas LMS/Google Docs embeds by TheGlassPenguin

/* ==UserStyle==
@name           Remove 'cloud assignment' explanation from the top bar in Canvas LMS Google Docs embeds
@namespace      theglasspenguin.us.to
@version        1.0.0
@description    Does exactly what it says on the tin. Basically removes the large "The embedded document below" thing from the top bar, leaving only the link and submit button, so you have more space to work with.
@author         TheGlassPenguin (theglasspenguin.us.to)
==/UserStyle== */

@-moz-document url-prefix("https://google-drive-lti-iad-prod.instructure.com") {
/* It's only one class, with one rule. Simple enough. I could have minified it, but that wouldn't be nice of me, wouldn't it? */
    .app-content > div > div > div:nth-of-type(1)
    {
        display: none;
    }
}