For decades (literally, since 1978), programmers have used static analyzers called linters to find and fix stylistic and formatting errors in code. For many years, CSS was without tools like this, and knowing the intriciacies of cross-browser compatibility was a sort of ancestral lore, proven in the wild and stored in the dome. But now, since 2014, CSS has its own full-featured linter, Stylelint, that not only finds and fixes formatting errors, but with an extensible set of plugins, can also fix and flag all sorts of other errors.
See also: HTMLhint (not lint)
Here’s my config (synced + backed up with Mackup, of course):