Sass.
It's a Game-Changer.

una.github.io/slides-intro-to-sass

Sass...!?

Sass:

Syntactically Awesome Style Sheets: Sass is the most mature, stable, and powerful professional grade CSS extension language in the world. sass-lang.com

Sass...!?

Sass is a CSS preprocessor.

CSS

.navbar .nav .dropdown-toggle .caret, .navbar .nav .open.dropdown .caret {
  border-top-color: #ffffff;
}
.navbar .nav .active .caret {
  opacity: 1;
  filter: alpha(opacity=100);
}
.navbar .nav .open > .dropdown-toggle, .navbar .nav .active > .dropdown-toggle, .navbar .nav .open.active > .dropdown-toggle {
  background-color: transparent;
}
.navbar .nav .active > .dropdown-toggle:hover {
  color: #ffffff;
}
.navbar .nav.pull-right .dropdown-menu {
  left: auto;
  right: 0;
}
.navbar .nav.pull-right .dropdown-menu:before {
  left: auto;
  right: 12px;
}
.navbar .nav.pull-right .dropdown-menu:after {
  left: auto;
  right: 13px;
}
.breadcrumb {
  padding: 7px 14px;
  margin: 0 0 18px;
  background-color: #fbfbfb;
  background-image: -moz-linear-gradient(top, #ffffff, #f5f5f5);
  background-image: -ms-linear-gradient(top, #ffffff, #f5f5f5);
  background-image: -webkit-gradient(linear, 0 0, 0 100%, from(#ffffff), to(#f5f5f5));
  background-image: -webkit-linear-gradient(top, #ffffff, #f5f5f5);
  background-image: -o-linear-gradient(top, #ffffff, #f5f5f5);
  background-image: linear-gradient(top, #ffffff, #f5f5f5);
  background-repeat: repeat-x;
  filter: progid:DXImageTransform.Microsoft.gradient(startColorstr='#ffffff', endColorstr='#f5f5f5', GradientType=0);
  border: 1px solid #ddd;
  -webkit-border-radius: 3px;
  -moz-border-radius: 3px;
  border-radius: 3px;
  -webkit-box-shadow: inset 0 1px 0 #ffffff;
  -moz-box-shadow: inset 0 1px 0 #ffffff;
  box-shadow: inset 0 1px 0 #ffffff;
}
.breadcrumb li {
  display: inline-block;
  text-shadow: 0 1px 0 #ffffff;
}
.breadcrumb .divider {
  padding: 0 5px;
  color: #999999;
}
.breadcrumb .active a {
  color: #333333;
}
.pagination {
  height: 36px;
  margin: 18px 0;
}
.pagination ul {
  display: inline-block;
  *display: inline;
  /* IE7 inline-block hack */

  *zoom: 1;
  margin-left: 0;
  margin-bottom: 0;
  -webkit-border-radius: 3px;
  -moz-border-radius: 3px;
  border-radius: 3px;
  -webkit-box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
  -moz-box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}
.pagination li {
  display: inline;
}
.pagination a {
  float: left;
  padding: 0 14px;
  line-height: 34px;
  text-decoration: none;
  border: 1px solid #ddd;
  border-left-width: 0;
}
.pagination a:hover, .pagination .active a {
  background-color: #f5f5f5;
}
.pagination .active a {
  color: #999999;
  cursor: default;
}
.pagination .disabled a, .pagination .disabled a:hover {
  color: #999999;
  background-color: transparent;
  cursor: default;
}
.pagination li:first-child a {
  border-left-width: 1px;
  -webkit-border-radius: 3px 0 0 3px;
  -moz-border-radius: 3px 0 0 3px;
  border-radius: 3px 0 0 3px;
}
.pagination li:last-child a {
  -webkit-border-radius: 0 3px 3px 0;
  -moz-border-radius: 0 3px 3px 0;
  border-radius: 0 3px 3px 0;
}
.pagination-centered {
  text-align: center;
}
.pagination-right {
  text-align: right;
}
.pager {
  margin-left: 0;
  margin-bottom: 18px;
  list-style: none;
  text-align: center;
  *zoom: 1;
}
.pager:before, .pager:after {
  display: table;
  content: "";
}
.pager:after {
  clear: both;
}
.pager li {
  display: inline;
}
.pager a {
  display: inline-block;
  padding: 5px 14px;
  background-color: #fff;
  border: 1px solid #ddd;
  -webkit-border-radius: 15px;
  -moz-border-radius: 15px;
  border-radius: 15px;
}
.pager a:hover {
  text-decoration: none;
  background-color: #f5f5f5;
}
.pager .next a {
  float: right;
}
.pager .previous a {
  float: left;
}

But Really,
It's a Game-Changer

Organization
Theming
Logic
Low Barrier to Entry

Installation and Getting Started

Ruby Sass

ruby
gem install sass
sass –watch input.scss:output.css

Node Sass

node
npm install node-sass
sass –watch input.scss:output.css

More Resources:

Watching folders

Sass Basics

Syntax
Variables
Variable Abstraction
Nesting
Ampersands
Selector Inheritance & @extend
Placeholder Selectors
Partials & @import

Syntax

.sass

              #sidebar
  width: 30%
  background-color: #faa

Variables: !

Assignment: =

.scss

              #sidebar {
  width: 30%;
  background-color: #faa;
}

Variables: $
Assignment: :

More Resources:

Variables

Placeholders for values used multiple times.

.scss

              $open-sans-stack: 'Open Sans', Arial, Helvetica, sans-serif;
$pink: #c69;

body {
  font-family: $open-sans-stack;
}

h2 {
  color: $pink;
}

.css output

            body {
  font-family: "Open Sans", sans-serif;
}

h2 {
  color: #c69;
}

More Resources:

Thoughtbot on Sass Variables

Variable Abstraction

Variables should be abstracted into themes.

.scss

              // variables.scss
$open-sans-stack: 'Open Sans', Arial, Helvetica, sans-serif;
$pink: #c69;

// theme.scss
$font--copy: $open-sans-stack;
$header--color: $pink;


// typography.scss
body {
  font-family: $open-sans-stack;
}

h2 {
  color: $header--color;
}

.css output

            body {
  font-family: "Open Sans", sans-serif;
}

h2 {
  color: #c69;
}

Nesting

Nesting allows you to organize your code in relevant chunks

.scss

              .sidebar {
  float: left;

  h2 {
    font-size: 1.2em;
  }
}

.css output

              .sidebar {
  float: left;
}
.sidebar h2 {
  font-size: 1.2em;
}

A word on Nesting

Never go more than 3 levels deep
Nesting with an & is a-okay

When Nesting Goes Wrong

Do not do this.

.scss

              body {
  sidebar {
    .news-section {
      .description {
        a {
          color: #f00;
        }
      }
    }
  }
}

.css output

              body sidebar .news-section .description a {
  color: #f00;
}

Yay Nesting!

.scss

              $blue: #00f;

.blue-link {
  color: $blue;

  &:hover,
  &:focus {
    color: mix($blue, white, 50%);
  }
}

.css output

              .blue-link {
  color: #00f;
}
.blue-link:hover, .blue-link:focus {
  color: #7f7fff;
}

The almighty ampersand

Great for BEM, SMACSS & other syntax methodologies
No long selectors!

More Resources:

The Trailing Ampersand

.scss

              .unicorn {
  .set-one & {
    display: none;
  }
}

.button--large {
  .sidebar & {
    font-size: 80%;
  }
}

.css output

              .set-one .unicorn {
  display: none;
}

.sidebar .button--large {
  font-size: 80%;
}

More Resources:

The Almighty Ampersand
Sass Trailing Ampersand

@extend (Selector Inheritance)

Extending will append the element to recieve the style block.

.scss

              .kitten {
  background-image: url("../img/kitten.png");
}

.kitten-with-hat {
  @extend .kitten;

  &:after {
    content: " ";
    background-image: url("../img/hat.png");
  }
}

.css output

              .kitten, .kitten-with-hat {
  background-image: url("../img/kitten.png");
}

.kitten-with-hat:after {
  content: " ";
  background-image: url("../img/hat.png");
}

.kitten

.kitten-with-hat

Placeholder Selectors

Placeholders are "invisible" until extended

.scss

              $pink: #c69;
$blue: #00f;

// I'm not real yet
%link {
  text-decoration: none;
  font-weight: 300;
}

.pink-link {
  @extend %link; //extending
  color: $pink;
}

.blue-link {
  @extend %link; //extending
  color: #00f;
}

.css output

              .pink-link, .blue-link {
  text-decoration: none;
  font-weight: 300;
}

.pink-link {
  color: #c69;
}

.blue-link {
  color: #00f;
}

Partials & @import

Sass files are split into "partials" for better organization.

Manifest File (main.scss)

              @import "vendors/bootstrap";
@import "vendors/jquery-ui";

@import "utils/variables";
@import "utils/functions";
@import "utils/mixins";
@import "utils/placeholders";

@import "base/reset";
@import "base/typography";

@import "layout/navigation";
@import "layout/grid";
@import "layout/header";
@import "layout/footer";
@import "layout/sidebar";
@import "layout/forms";

@import "components/buttons";
@import "components/carousel";
@import "components/cover";
@import "components/dropdown";

@import "pages/home";
@import "pages/contact";

@import "themes/theme";
@import "themes/admin";

More Resources:

Sass Director
Wrangling Sass @import files

Using Mixins

Mixins & @include

Mixins & arguments

The arglist...

Mixins & @content

Mixins & @include

Mixins are blocks of code you @include

.scss

              @mixin center-block {
  display: block;
  margin-left: auto;
  margin-right: auto;
}

.nyan-cat {
  width: 450px;
  @include center-block; //including here
}

.css output

              .nyan-cat {
  width: 450px;
  display: block;
  margin-left: auto;
  margin-right: auto;
}

More Resources:

Handy Sass Mixins

Mixins + Arguments

Mixins can accept parameters, making them even more flexible

.scss

              @mixin box-shadow($shadow) {
  -webkit-box-shadow: $shadow;
     -moz-box-shadow: $shadow;
          box-shadow: $shadow;
}

.box {
  @include box-shadow(0 0 0 3px #aaa)
}

.css output

  .box {
  -webkit-box-shadow: 0 0 0 3px #aaa;
  -moz-box-shadow: 0 0 0 3px #aaa;
  box-shadow: 0 0 0 3px #aaa;
}

The Arglist

@mixin shadows($shadows...) {
  box-shadow: $shadows;
}

More Resources:

Sass Arglist

Mixins and @content

Mixins can take a variety of args, including @content blocks.

.scss

              //mixin
@mixin smaller-than($width) {
  @media (max-width: $width) {
    @content;
  }
}

@mixin larger-than($width) {
  @media (min-width: $width) {
    @content;
  }
}

//usage
.heading {
  font-size: 2em;
  @include smaller-than(300px) {
    font-size: 1.5em;
  }
  @include larger-than(768px) {
    font-size: 3em;
  }
}

.css output

              .heading {
  font-size: 2em;
}
@media (max-width: 300px) {
  .heading {
    font-size: 1.5em;
  }
}
@media (min-width: 768px) {
  .heading {
    font-size: 3em;
  }
}

More Resources:

Media Queries in Sass

Control Directives & Functions

Lists
Maps
@each loop
@for loop
Math
Color Functions

Lists

Basic List

              $social-icons: twitter, facebook, instagram, dribbble;

Space-seperated Values

              $types: text #f00, photo #c69, video #c0ffee, link #bada55;

More Resources:

Understanding Sass Lists
Advanced Sass List Functions

Lists in Action

Note: Sass Lists start at 1, not 0.

.scss

              $types: text #f00, photo #c69, video #c0ffee, link #bada55;

@each $type in $types {
     .post-type-#{nth($type, 1)} .post-icon{
        background: nth($type, 2);
    }
}

.css output

              .post-type-text .post-icon {
  background: #f00;
}

.post-type-photo .post-icon {
  background: #c69;
}

.post-type-video .post-icon {
  background: #c0ffee;
}

.post-type-link .post-icon {
  background: #bada55;
}

List Functions

Maps

Maps are structured in key: value pairs and accessed with map-get($map-name, key).

.scss

              $breakpoints: (
  small: 767px,
  medium: 992px,
  large: 1200px
);

.sidebar {
  width: 30%;

    @media (max-width: map-get($breakpoints, small)) {
      width: 100%;
    }
}

.css output

              .sidebar {
  width: 30%;
}
@media (max-width: 767px) {
  .sidebar {
    width: 100%;
  }
}

More Resources:

Sass Maps are Awesome!
Using Sass Maps

Map Functions

@each loop

@each loop

.scss

                @import 'compass';

$colors: (
  tomato rgb(255,99,71) 'rgb(255,99,71)',
  'cornflowerblue' rgb(100,149,237) 'rgb(100,149,237)',
  gold rgb(255,215,0) 'rgb(255,215,0)',
  hotpink rgb(255,105,180) 'rgb(255,105,180)',
);

@each $color in $colors {
  $var-name: nth($color, 1);
  $hex: nth($color, 2);
  $css-name: nth($color, 3);
  .color-box.#{$var-name} {
    @include contrasted($hex);
    &:before {
      content: '#{$var-name}';
    }
    &:after {
      content: '#{$css-name}';
    }
  }
}

.css output

                .color-box.tomato {
  background-color: tomato;
  color: #000;
}
.color-box.tomato:before {
  content: "tomato";
}
.color-box.tomato:after {
  content: "rgb(255,99,71)";
}

.color-box.cornflowerblue {
  background-color: cornflowerblue;
  color: #000;
}
.color-box.cornflowerblue:before {
  content: "cornflowerblue";
}
.color-box.cornflowerblue:after {
  content: "rgb(100,149,237)";
}

.color-box.gold {
  background-color: gold;
  color: #000;
}
.color-box.gold:before {
  content: "gold";
}
.color-box.gold:after {
  content: "rgb(255,215,0)";
}

.color-box.hotpink {
  background-color: hotpink;
  color: #000;
}
.color-box.hotpink:before {
  content: "hotpink";
}
.color-box.hotpink:after {
  content: "rgb(255,105,180)";
}

@for loop

For loop using through

.scss

              $columns: 4;

@for $i from 1 through $columns {
  .cols-#{$i} {
    width: ((100 / $columns) * $i) * 1%;
  }
}

.css output

              .cols-1 {
  width: 25%;
}

.cols-2 {
  width: 50%;
}

.cols-3 {
  width: 75%;
}

.cols-4 {
  width: 100%;
}

More Resources:

Handy Advanced Sass

@for loop

For loop using to

.scss

              $columns: 4;

@for $i from 1 to $columns {
  .cols-#{$i} {
    width: ((100 / $columns) * $i) * 1%;
  }
}

.css output

              .cols-1 {
  width: 25%;
}

.cols-2 {
  width: 50%;
}

.cols-3 {
  width: 75%;
}

More Resources:

Handy Advanced Sass

Supported Operators

Calculation

Comparison

Number Functions

Math with Color

Input:

p {
  color: #010203 + #040506;
}

01 + 04 = 05, 02 + 05 = 07, and 03 + 06 = 09

Computed Value:

p {
  color: #050709;
}

More Resources:

Sass Functions Docs

Playing with Color

See the Pen Experiments with Sass Color Functions by KatieK (@KatieK2) on CodePen.

More Resources:

A Visual Guide to Sass & Compass Color Functions

Note: Mix > Lighten or Darken

See the Pen Dadgumit, Blowouts by KatieK (@KatieK2) on CodePen.

Pulling it Together

Mixins + Maps
A Sassy Shape Mixin
Theming with Maps
Advanced Trigonometric Sass
Sass Weather App

Mixins and Maps

.scss

              //our map of breakpoints from earlier
$breakpoints: (
  small: 767px,
  medium: 992px,
  large: 1200px
);

//mixin using map-get
@mixin smaller-than($point-name) {

  $width: map-get($breakpoints, $point-name);
  @media (max-width: $width) {
    @content;
  }
}

@mixin larger-than($point-name) {

  $width: map-get($breakpoints, $point-name);
  @media (min-width: $width) {
    @content;
  }
}

//usage
.heading {
  font-size: 2em;
  @include smaller-than(small) {
    font-size: 1.5em;
  }
  @include larger-than(medium) {
    font-size: 3em;
  }
}

.css output

              .heading {
  font-size: 2em;
}
@media (max-width: 300px) {
  .heading {
    font-size: 1.5em;
  }
}
@media (min-width: 768px) {
  .heading {
    font-size: 3em;
  }
}

Sassy Shapes Mixin

Mixins can take values and run logic loops.

See the Pen Sassy Shape Machine Mixin by Una Kravets (@unax3) on CodePen.

Sassy Shapes Mixin

Putting it to use.

See the Pen Sassy CSS Puppy by Una Kravets (@unax3) on CodePen.

Theming using Maps

variables.scss

              $__color-palette: (
  'blue': (
    core: #4178be,
    10: #c0e6ff,
    20: #7cc7ff,
    30: #5aaafa,
    40: #5596e6,
    50: #4178be,
    60: #325c80,
    70: #264a60,
    80: #1d3649,
    90: #152935,
    100: #010205
  ),
  'green': (
    core: #4b8400,
    10: #c8f08f,
    20: #b4e051,
    30: #8cd211,
    40: #6eb400,
    50: #4b8400,
    60: #2d660a,
    70: #144d14,
    80: #0a3c02,
    90: #0c2808,
    100: #010200
  ),
  'teal': (
    core: #008571,
    10: #a7fae6,
    20: #6eedd8,
    30: #41d6c3,
    40: #00b4a0,
    50: #008571,
    60: #006d5d,
    70: #005448,
    80: #003c32,
    90: #012b22,
    100: #000202
  ),
  'purple': (
    core: #9855d4,
    10: #eed2ff,
    20: #d7aaff,
    30: #ba8ff7,
    40: #af6ee8,
    50: #9855d4,
    60: #734098,
    70: #562f72,
    80: #412356,
    90: #311a41,
    100: #030103
  ),
  'magenta': (
    core: #db2780,
    10: #ffd2ff,
    20: #ff9eee,
    30: #ff71d4,
    40: #ff3ca0,
    50: #db2780,
    60: #a6266e,
    70: #7c1c58,
    80: #601146,
    90: #3a0b2e,
    100: #040102
  )
);

functions.scss

              // Import the IBM Color Palette
@import '../variables/colors';

//////////////////////////////
// Color Palette
//
// Gets the specified color from the color palette
//
// Usage:
//
// background: color('blue', 80); // #1D3649
// background: color('blue');     // #4178BE
//////////////////////////////
@function color($color, $tone: 'core') {
  // Add a little helper so tone can be passed as single digit number
  @if type-of($tone) == 'number' {
    @if $tone % 10 == $tone {
      $tone: $tone * 10;
    }
  }
  @return map-get(map-get($__color-palette, $color), $tone);
}

More Resources:

Using Maps in Color Pallets

Theming Using Maps

A better look at functions.scss

              // Import the IBM Color Palette
@import '../variables/colors';

//////////////////////////////
// Color Palette
//
// Gets the specified color from the color palette
//
// Usage:
//
// background: color('blue', 80); // #1D3649
// background: color('blue');     // #4178BE
//////////////////////////////
@function color($color, $tone: 'core') {
  // Add a little helper so tone can be passed as single digit number
  @if type-of($tone) == 'number' {
    @if $tone % 10 == $tone {
      $tone: $tone * 10;
    }
  }
  @return map-get(map-get($__color-palette, $color), $tone);
}

Advanced Trigonometric Functions

See the Pen Pure CSS 3D animated icosidodecahedron (pentagonal gyrobirotunda) by Ana Tudor (@thebabydino) on CodePen.

More Resources:

Inverse Trig Functions in Sass
Trigonometry in Sass

Ana Tudor, FTW

See the Pen Cube truncation sequence (pure CSS 3D animation) by Ana Tudor (@thebabydino) on CodePen.

Sass. It's a Game-Changer.

una.github.io/slides-intro-to-sass

Sass...!?

Sass:

Sass...!?

CSS

But Really, It's a Game-Changer

Installation and Getting Started

Ruby Sass

Node Sass

More Resources:

Sass Basics

Syntax

.sass

.scss

More Resources:

Variables

.scss

.css output

More Resources:

Variable Abstraction

.scss

.css output

Nesting

.scss

.css output

A word on Nesting

When Nesting Goes Wrong

.scss

.css output

Yay Nesting!

.scss

.css output

The almighty ampersand

More Resources:

The Trailing Ampersand

.scss

.css output

More Resources:

@extend (Selector Inheritance)

.scss

.css output

.kitten

.kitten-with-hat

Placeholder Selectors

.scss

.css output

Partials & @import

Manifest File (main.scss)

More Resources:

Using Mixins

Mixins & @include

.scss

.css output

More Resources:

Mixins + Arguments

.scss

.css output

The Arglist

More Resources:

Mixins and @content

.scss

.css output

More Resources:

Control Directives & Functions

Lists

Basic List

Space-seperated Values

More Resources:

Lists in Action

.scss

.css output

List Functions

Maps

.scss

.css output

More Resources:

Map Functions

@each loop

@each loop

Sass.
It's a Game-Changer.

But Really,
It's a Game-Changer