Style Fixes

[0x4007]

• [x] - I just realized that the color for the timer bar on the toaster is not rendering.
• [x] - opacity for header needs to be dimmed on light mode.
• [x] - opacity too low for beneficiary name.

  Need to fix.

• [x] - Background and body elements should span to fill sides in dark mode

Originally posted by @pavlovcik in https://github.com/ubiquity/pay.ubq.fi/issues/93#issuecomment-1630177372

[ubiquibot[bot]]

[ CLAIM 12.5 WXDAI ]

0x4007CE208...C149a341d