This is a overview of the most popular CSS methodologies being used today. It covers examples and workflows using tools like sass and gulp.

1. OOCSS, SMACSS or BEM?
@micposso

2. Michael Posso
Front-End developer @babbel NYC
Email Marketing
MeetUp Organizer
@micposso

3. Tables base structure
Lots of #ID selectors
Separate Structure from Styles
Animated GIFs
No semantics
Adobe FLASH!!!!
Old School “Web Design”

4. (DRY)
Don’t repeat yourself

5. (SEMANTICS)
Semantics is the study of the meaning of
linguistic expressions

6. (Object Oriented)
A system to be modeled as a set of objects that can be
controlled and manipulated in a modular manner
< Inheritance, can be extended and reusable >

7. (CSS Specificity)
Every selector has its place in the specificity hierarchy
smashingmagazine.com/2007/07/css-specificity-things-you-should-know/

8. (Comment you code)
Help your fellow coders

9. Samples of CSS comment styles
/* ====== media ====== */
/* _header styles */
/*
* — Section Heading —
*/
/**
* High level descriptions or summaries
*/
http://cssguidelin.es/#commenting

10. Semantics in HTML5 and CSS
HTML5 introduced a new elements that can improve semantics of
your code. With this semantic elements and semantic naming in your
CSS classes, they can complement each other.
<nav class=”primary”>
</nav>
<section class=”main”>
</section>
<aside class=”sidebar”>
</aside>

11. How to apply semantics in a global team
Global teams deal with a variety of cultures and linguistics differences
that can make semantics hard to apply.
Guidelines document
Use Interfaces
Delegate a reviewer

12. CSS Resets, which one you use?
“The reset styles given here are intentionally very generic. I don’t
particularly recommend that you just use this in its unaltered state in
your own projects. It should be tweaked, edited, extended, and
otherwise tuned to match your specific reset baseline”.
Eric Meyer
Eric Myer’s Reset
HTML5 Doctor
Your own?

13. (OOCSS)
Object Oriented CSS

14. OOCSS
Nicolle Sullivan 2009
github.com/stubbornella/oocss/wiki
slideshare.net/stubbornella/object-oriented-css

15. OOCSS Principles
Separate Structure and Skin
LAYOUT VS STYLES
Separate Container from Content
CONTAINER is not affected by its CONTENT

16. Object Oriented CSS Best Practices
Classes instead of IDs for styling
No multi-level descendant class specificity unless needed
Define your design in “Components”
Extend elements with targeted classes rather than parent classes
Mix and Match components
Organize your stylesheet into sections
Consider adding a table of contents
Camel case your class names - naming is oriented around the “object”

17. Basic Structure
Reset
GRID
Text styles
-headings
-content
Content Styles
-top level styles
-component specific

18. Identify Common Properties
.button1 {border-radius, height, color, font style, line-height, padding}
.button2 {border-radius, height, color, font style, line-height, padding}
.button3 {border-radius, height, color, font style, line-height, padding}
<div class=”button1”>Buy Now</div>
<div class=”button2”>More Information</div>
<div class=”button3”>Go Back</div>

19. OOCSS Way
.button-skin {border-radius, height, padding}
.cta {color, background-color}
.attention {color, background-color}
.enable {color, background-color}
<div class=”button-skin cta”>Buy Now</div>
<div class=”button-skin attention”>More Information</div>
<div class=”button-skin enable”>Go Back</div>

20. The Media Object Example
<div class="media">
<a href="http://twitter.com/stubbornella" class="img">
<img src="img.jpg" alt="Stubbornella" />
</a>
<div class="bd">
<p>@Stubbornella</p>
</div>
</div>
https://github.com/stubbornella/oocss/wiki/Content

21. The Media Object Example
/* ====== media ====== */
.media {margin:10px;}
.media, .bd {overflow:hidden; _overflow:visible; zoom:1;}
.media .img {float:left; margin-right: 10px;}
.media .img img{display:block;}
.media .imgExt{float:right; margin-left: 10px;}
https://github.com/stubbornella/oocss/wiki/Content

22. The Media Object Example (html + css)

23. Tradeoffs
Bloating of the HTML
More CSS rules
Have to update HTML to make changes
Benefits
Maintainable and organized*
Easy to implement, no tools necessary
DRY CSS
Good for big and small projects

24. (SMACSS)
Scalable Modular Architecture for CSS

25. SMACSS
Developed by Jonathan Snook
@snookca
https://snook.ca/
https://smacss.com/

26. Categorizing CSS Rules
1. Base
2. Layout
3. Module
4. State
5. Theme - Optional

27. File Architecture with Plain CSS
index.css - This is what will be linked in the HTML head. It uses
@import to bring the rest of the files into the document
base.css - reset, IDs and Element selectors OK
layout.css
theme.css - optional
module.css - will import other files from the modules folder
Modules folder
-media.css
-text-box.css

28. Using Sass
index.scss
_base.scss
_layout.scss
_theme.scss - optional
_module.scss
_var.scss
_utils.scss
Modules folder
-media.scss
-text-box.scss

29. (Space Naming)
Use space naming with SMACSS

30. Space Naming for Classes
layout.css
.l-right {float: right;}
.l-left {float: left;}
.l-align-center {text-align: center;}
.l-align-left {text-align: left;}
.l-align-right {text-align: right;}

31. Space Naming for Classes
modules/cards.css
.card {}
.card--label {}
.card--meta {}
.card--meta {}
.card--copy {}

32. Tradeoffs
Complicated Structure
Requires precompiler *
Bloating HTML with classes
Benefits
Maintainable and organized*
Faster rendering by using OOCSS principles
DRY CSS
Great for big projects with cross-functional teams

33. (BEM)
Block - Element - Modifier

34. BEM
Developed by Yandex
en.bem.info
It provides a rather strict way to
arrange your CSS classes into
independent modules

35. BEM best practices
Everything is a class
Avoid nesting of any kind
Keep CSS specificity very flat and low
Descriptive names for classes
Avoid element selectors
CSS classes in BEM are called entities

36. (BEM)
BEM goal is to help developers better understand the
relationship between the HTML and CSS in a given project

37. BEM classes relationship
.btn = BLOCK
.btn__price = ELEMENT Is the class that depends on .btn to work
.btn--orange= MODIFIER Extend the .btn class
A representation of a web page structure in terms of blocks, elements,
and modifiers
BEM tree

38. Using BEM naming conventions
/* Block component */
.btn {}
/* Element that depends upon the block */
.btn__price {}
/* Modifier that changes the style of the block */
.btn--orange {} or .btn__price--orange

39. HTML with BEM classes
<a class="btn btn--big btn--orange" href="http://google.com">
<span class="btn__price">$9.99</span>
<span class="btn__text">Subscribe</span>
</a>

40. How about JavaScript?
If you are using ID to select DOM element withJavaScript, try to use a
semantic name that describes the behavior.
$("js_btn--fadein").click(function(){ $("#div1").fadeIn();});
jQuery
<button class=”btn__cta btn--orange” id=”js_btn--fadein”>
BUY NOW $9.99</button>
HTML

41. Tradeoffs
Bloating HTML with classes
Ugly, Ugly, Ugly
Long *&^#$ class names
Benefits
Maintainable and organized*
Relationships are defined in the naming conventions
Great for big and small projects with cross-functional teams