Weekend styling updates and mobile responsiveness

[YB-BigSwan]

Just started with the week calendar on the homepage. Will continue soon.

[github-actions[bot]]

Visit the preview URL for this PR (updated for commit e64e9b2):

https://satakuntalainenosakunta--pr39-next-site-cu0x6z4b.web.app

_{(expires Wed, 02 Oct 2024 12:07:36 GMT)}

_{🔥 via Firebase Hosting GitHub Action 🌎}

_{Sign: 1ec35f964edce5d08911a93688b4dc7a051b997f}

[YB-BigSwan]

Ready enough to merge. Will shower and head to SatO to work until the meeting starts.