How I use Sass in my projects

I've previously posted about the three basic ways you can add CSS to your website. However, in modern web applications it's more common to use a CSS pre-processor such as Less, Stylus, or in my case, Sass.

A CSS pre-processor extends the functionality of CSS by adding variables, operators, interpolations, functions, mixins and many more useful features.

Files are processed on a server or via a build tools such as Gulp or Webpack and the result is compiled down to standard CSS which is readable by all browsers.

You can find out more about different pre-processers here.

A Quick Introduction to Sass

Sass comes in two flavours.sass (classic Sass), and .scss ("Sassy CSS").

Essentially the difference is that .sass uses an indented notation which removes curly braces { } and relies on white-space and indenting to handle CSS declaration blocks, whereas .scss is more reminiscent of plain CSS.

For the purpose of this article I will be using .scss which is my preferred version.

How I organise my Sass files

Here is how I organise my Sass files when starting a new project.

styles/
|
|____base/
| |____  _base.scss
| |____  _mixins.scss
| |____  _reset.scss
| |____  _utility.scss
| |____  _variables.scss
|
|____components/
| |____  _buttons.scss
| |____  _footer.scss
| |____  _header.scss
| |____  _layout.scss
| |____  ... more components
|
|____main.scss

See the full structure on GitHub.

Lets break this structure down a little.

Entry point

My main entry point is located at /styles/main.scss. This is the file that gets processed by my build process and compiled down to main.css. The entry point file imports all other Sass component files.

main.scss
@import "base/reset";

@import "base/variables";
@import "base/mixins";
@import "base/base";
@import "base/typography";

@import "components/layout";
@import "components/header";
@import "components/footer";

@import "components/article";
@import "components/author";
@import "components/buttons";
@import "components/code";
// More components, sorted alphabetically

@import "base/utility";

I dont really add any comments to this file, but I use line breaks to organise the imported files into groups. The order of these imports is important as the compiled output .css file will be organised in this order. Importing files in the wrong order could affect the cascade and styles my be overridden.

Base

I start by importing a copy of Eric Meyer's CSS Reset to get rid of any browser inconsistencies. This is followed by variables and mixins which are needed to interpolate values throughout the rest of the code base.

base/_base.scss contains styling for base HTML elements. There are no root-level classes or ID's in this file. This one file alone sets up the styling for more than half of a website due to cascading.

base/_typography.scss sets up the styling for all headers, paragraphs, links, and anything else involving text. Again, no root-level classes here.

Finally, the base directory has a _utility.scss file which is imported at the end of main.scss. This file contains a few override classes, some of which have !important on the end which is why this file is imported last  to prevent any specificity clashing.

Components

All other styling sits in the components folder and I aim to break down everything into components. All files are named in hyphenated lowercase and the css declaration inside each file ususally begins with the same name, e.g

_footer.scss
.footer {
  display: flex;
  align-items: center;
  @include font-size(14px);

  // More styling...
}

I follow the BEM methodology while writing Sass and aim to keep my nesting to a maximum of 4 levels deep (give or take)!

Wrapping up

And that's pretty much the structure I use for all project which use Sass. At my day job we do have a few projects which keep Sass files in the same folder as the associated markup and JavaScript and use Webpack to compile these, but my preferred method is to keep all Sass files in one place.

What do you think of this strucutre? Is there anything you would do differently? How do you structure your projects? Let me know in the comments below.

Further Reading

An Introduction to CSS Pre-Processors: SASS, LESS and Stylus

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I’m Ajay Karwal. I write about my experiences as a front-end developer. If you enjoy my content, please consider supporting what I do.

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