The CSS handling system is now in Rust, and is massively parallel (Rust lets us do this easily), which is why that is faster. This leads to significant performa

The CSS handling system is now in Rust, and is massively parallel (Rust lets us do this easily), which is why that is faster. This leads to significant performance benefits because CSS cascading/"styling" happens pretty often, including on every DOM manipulation, and can slow down interactions. But also there has been a major push to fix performance issues in other parts of the browser which itself has lead to significant improvements across the board.