[web] Remove unused styles

Summary: These styles no longer exist and I believe were left in by mistake.

Test Plan: NA

Reviewers: varun, def-au1t, benschac, ashoat

Reviewed By: benschac, ashoat

Subscribers: ashoat, Adrian, karol-bisztyga

Differential Revision: https://phabricator.ashoat.com/D3305