enhance: use misskey shadow for the sharkey ticker, prevent clipping

Created by: alicem

What

Before:

After:

Let me know if the shadow change is unwanted, tho I think it looks nicer anyway, esp when zoomed in

Why

See the issue

Additional info (optional)

Fixes #290 (closed)

Checklist

• Read the contribution guide
• Test working in a local environment
• (If needed) Add story of storybook
• (If needed) Update CHANGELOG.md
• (If possible) Add tests