SVGs are all broken, and some of the more exotic colours haven't been updated. There's been no attempt to use SASS to remove duplication from the CSS yet.
no attempt to switch it at runtime yet.
For some reason, Chrome doesn't seem to make the central div in the
notifications warning wide enough, so it ends up wrapping. Fix this by making
the central div expand across the available space, instead of letting the
container for the close button do it.
Fixes https://github.com/vector-im/vector-web/issues/1687
