Sass Basics
Introduction
- Documentation (opens in a new tab) (sass-lang.com)
- Learn X in Y minutes (opens in a new tab) (learnxinyminutes.com)
Variables
$defaultLinkColor: #46EAC2;
a {
color: $defaultLinkColor;
}
String interpolation
$wk: -webkit-;
.rounded-box {
#{$wk}border-radius: 4px;
}
Comments
/*
Block comments
Block comments
Block comments
*/
// Line comments
Mixins
@mixin heading-font {
font-family: sans-serif;
font-weight: bold;
}
h1 {
@include heading-font;
}
See: Mixins
Nesting {.row-span-2}
.markdown-body {
a {
color: blue;
&:hover {
color: red;
}
}
}
to properties
text: {
// like text-align: center
align: center;
// like text-transform: uppercase
transform: uppercase;
}
Extend
.button {
···
}
.push-button {
@extend .button;
}
@import
@import './other_sass_file';
@import '/code', 'lists';
// Plain CSS @imports
@import "theme.css";
@import url(theme);
The .sass
or .sass
extension is optional.
Sass Mixins
Parameters
@mixin font-size($n) {
font-size: $n * 1.2em;
}
body {
@include font-size(2);
}
Default values
@mixin pad($n: 10px) {
padding: $n;
}
body {
@include pad(15px);
}
Default variable
$default-padding: 10px;
@mixin pad($n: $default-padding) {
padding: $n;
}
body {
@include pad(15px);
}
Sass Color functions {.cols-2}
rgba
rgb(100, 120, 140)
rgba(100, 120, 140, .5)
rgba($color, .5)
Mixing
mix($a, $b, 10%) // 10% a, 90% b
Modifying HSLA
darken($color, 5%)
lighten($color, 5%)
saturate($color, 5%)
desaturate($color, 5%)
grayscale($color)
adjust-hue($color, 15deg)
complement($color) // like adjust-hue(_, 180deg)
invert($color)
fade-in($color, .5) // aka opacify()
fade-out($color, .5) // aka transparentize()
rgba($color, .5) // sets alpha to .5
Getting individual values
HSLA
hue($color) // 0deg..360deg
saturation($color) // 0%..100%
lightness($color) // 0%..100%
alpha($color) // 0..1 (aka opacity())
RGB
red($color) // 0..255
green($color)
blue($color)
See: hue() (opens in a new tab), red() (opens in a new tab)
Adjustments
// Changes by fixed amounts
adjust-color($color, $blue: 5)
adjust-color($color, $lightness: -30%) // darken(_, 30%)
adjust-color($color, $alpha: -0.4) // fade-out(_, .4)
adjust-color($color, $hue: 30deg) // adjust-hue(_, 15deg)
// Changes via percentage
scale-color($color, $lightness: 50%)
// Changes one property completely
change-color($color, $hue: 180deg)
change-color($color, $blue: 250)
Supported: $red
, $green
, $blue
, $hue
, $saturation
, $lightness
, $alpha
Sass Other functions {.cols-2}
Strings
unquote('hello')
quote(hello)
to-upper-case(hello)
to-lower-case(hello)
str-length(hello world)
str-slice(hello, 2, 5) // "ello" - it's 1-based, not 0-based
str-insert("abcd", "X", 1) // "Xabcd"
Units
unit(3em) // 'em'
unitless(100px) // false
Numbers
floor(3.5)
ceil(3.5)
round(3.5)
abs(3.5)
min(1, 2, 3)
max(1, 2, 3)
percentage(.5) // 50%
random(3) // 0..3
Misc
variable-exists(red) // checks for $red
mixin-exists(red-text) // checks for @mixin red-text
function-exists(redify)
global-variable-exists(red)
selector-append('.menu', 'li', 'a') // .menu li a
selector-nest('.menu', '&:hover li') // .menu:hover li
selector-extend(...)
selector-parse(...)
selector-replace(...)
selector-unify(...)
Sass Feature checks {.cols-2}
Feature check
feature-exists(global-variable-shadowing)
Features
- global-variable-shadowing
- extend-selector-pseudoclass
- units-level-3
- at-error
Sass Loops
For loops
@for $i from 1 through 4 {
.item-#{$i} { left: 20px * $i; }
}
Each loops (simple)
$menu-items: home about contact;
@each $item in $menu-items {
.photo-#{$item} {
background: url('#{$item}.jpg');
}
}
Each loops (nested)
$backgrounds: (home, 'home.jpg'),
(about, 'about.jpg');
@each $id, $image in $backgrounds {
.photo-#{$id} {
background: url($image);
}
}
While loops
$i: 6;
@while $i > 0 {
.item-#{$i} { width: 2em * $i; }
$i: $i - 2;
}
Sass Other features
Conditionals {.row-span-2}
@if $position == 'left' {
position: absolute;
left: 0;
}
@else if $position == 'right' {
position: absolute;
right: 0;
}
@else {
position: static;
}
Interpolation
.#{$klass} { ... } // Class
call($function-name) // Functions
@media #{$tablet}
font: #{$size}/#{$line-height}
url("#{$background}.jpg")
Lists
$list: (a b c);
nth($list, 1) // starts with 1
length($list)
@each $item in $list { ... }
Maps {.col-span-2}
$map: (key1: value1, key2: value2, key3: value3);
map-get($map, key1)