[Feature] CSS Basic architecture  

Preview: <a href="https://github.com/bblurock/sms-coding-standard/blob/front-end-BEM-draft/CSS.md">here</a>
嗯嗯，file size 也是蠻多人 argue 的點。

但也有人覺得現在有 Gzip 幫忙了，這些 overhead 應該最後再考慮。以可維護性，擴充性為較優先的考量。

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雖然這篇文章在講 utility classes (就是css 的 helper, ex: ```.pull-left```, ```.pull-right```)，但有討論到一些 filesize 的觀點，可以參考一下。
> 2 . Filesize  

>By taking repetition out of the CSS, utility classes reduce CSS filesize.
Preprocessors can't match this benefit. Using mixins and variables to repeat patterns and values does result in DRYness and consistency but does not cut back on the size of the delivered CSS: every repeated mixin and variable generates repeated declarations.  
Sass @extends can be used to reduce some repetition — but they are problematic in other, key ways. And rather than advocating @extends, I』d argue that this benefit is questionable. CSS filesize should be one of your last optimization concerns; and once Gzip gets involved, it's possible that the savings won't make a substantial difference. In any situation where the scalability of your CSS is at issue, where there's any danger of things getting messy and confusing and out-of-control, authoring and maintenance considerations should trump kilobyte savings.

[出處](http://davidtheclark.com/on-utility-classes/)