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// cc @tadatuta @verybigman 
I suggest to use freeze with base64 inlining and `clean-css` instead of `CSSO` (refer https://github.com/bem/project-stub/blob/bem-core/.enb/make.js#L93-L94).

and don't forget to add `clean-css` tech to `package.json` (refer https://github.com/bem/project-stub/blob/bem-core/package.json#L19)