New chat style!

The previous chat system made it difficult to differentiate tappable elements and messages, and readability wasn't great on messages from Evaline (our bot).

Additionally, important information would sometimes get drowned out in a sea of text. Darker button styles now sufficiently contrast other elements on the page, and colored user messages deviate from the otherwise monochrome interface. White Evaline messages allow important information to stand out, and also match other elements sent by Evaline, like sessions.

Excited to ⛴ on Monday!