Craig Mod does a bigger overhaul with Twitter for Minimalists, but this will only do the following:
- Hides promoted tweets and trends
- Hides the useless “Expand” link that appears under every tweet
- Tones down the blue conversation line to a barely-visible gray
- Hides all numbers
You can add this CSS in Safari with this extension. The URL to target is twitter.com/*.
Added this to hide the inline stats:
span.Icon.Icon--analytics { display: none; }