Compress and merge CSS without duplicate selectors

Question

css

Good day.
There is a task to reduce the volume of CSS files. MVC4 project.
For work, standard tools from System.Web.Optimization were used. There are conditionally 2 files: one normalize.css, the other with their own styles. The System.Web.Optimization.Styles.Render method concatenates files, compresses, but keeps duplicate selectors if they are repeated. For example, both have body, html, etc. I don’t feel like editing normalize.css by hand.
Question:
1. Is it possible to force System.Web.Optimization to combine duplicate selectors?
2. Perhaps there is a better library that solves this problem

Answer 1

In cases slightly more complex than elementary, it is impossible to combine CSS rules, because they are applied in the order in which they are defined.