Per your example I wonder if CSS engine devs optimize for most common use like many JS engines do. For example JS `for` loops, `for (let i=maxVal;i--;)` should

Per your example I wonder if CSS engine devs optimize for most common use like many JS engines do. For example JS `for` loops, `for (let i=maxVal;i--;)` should hypothetically perform better than `for (let i=0;i<=maxVal;i++)` but they are pretty much equal in modern interpreters.