Website Updates and Upgrades are still underway! We don't expect any further downtime, but we thank you for your patience as we restore themes and other elements including the Chatbox.
Beta of a completely new Steam chat. New friends list, new groups.
More information at this link https://steamcommunity.com/updates/chatupdate
Report problems - https://steamcommunity.com/groups/SteamClientBeta/discussions