1. What is LESS?What is LESS?
What is LESS?
- LESS=The dynamic stylesheet language.
- LESS extends the standard CSS syntax. This means that you can create a LESS
stylesheet using regular CSS, and just add LESS code to the stylesheet as and
when you need it.

2. Processing
- The LESS compiler is written in JavaScript.
- The compiler converts your LESS code into CSS when the browser loads the
page
ProcessingProcessing

3. Why LESS?Why LESS?
- LESS has everything that CSS is missing.
- Features:
1- Variables
2- Mixins
3- Nested rules
4- Operators and functions

4. VariablesVariables
- When you program you can set a constant variable that you can access throughout
your program.
- You can do the same with LESS. Set a variable named @red, add your favorite
hex red color and use it in your stylesheet.
- Wanna change the color a bit? Just change the @red value and smile

5. Variables (Cons)
Ex:
// LESS
@color: #4D926F;
#header {
color: @color;
}
h2 { color: @color; }
/* Compiled CSS */
#header {
color: #4D926F;
}
h2 {
color: #4D926F;
}

6. MixinsMixins
- allow you to embed all the properties of a class into another class by simply
including the class name as one of its properties.
Ex:
// LESS
.rounded-corners (@radius: 5px) {
border-radius: @radius; -webkit-border-radius: @radius;
-moz-border-radius: @radius;
}
#header {
.rounded-corners;
}
#footer {
.rounded-corners(10px);
}

7. /* Compiled CSS */
#header {
border-radius: 5px;
-webkit-border-radius: 5px;
-moz-border-radius: 5px;
}
#footer {
border-radius: 10px;
-webkit-border-radius: 10px;
-moz-border-radius: 10px;
}

8. Nested rulesNested rules
- You can simply nest selectors inside other selectors.
- These can save you a lot of coding, and they make your code clearer.
Bye bye long selectors!

9. Ex:
// LESS
#header {
h1 {
font-size: 26px;
font-weight: bold;
}
p {
font-size: 12px;
a {
text-decoration: none;
&:hover {
border-width: 1px
}
}
}
}
/* Compiled CSS */
#header h1 {
font-size: 26px;
font-weight: bold;
}
#header p {
font-size: 12px;
}
#header p a {
text-decoration: none;
}
#header p a:hover {
border-width: 1px;
}

10. Operators and functionsOperators and functions
- which let you create CSS properties mathematically.
Ex:
// LESS
@the-border: 1px;
@base-color: #111;
@red: #842210;
#header {
color: @base-color * 3;
border-left: @the-border;
border-right: @the-border * 2;
}
#footer {
color: @base-color + #003300;
border-color: desaturate(@red, 10%);
}
/* Compiled CSS */
#header {
color: #333;
border-left: 1px;
border-right: 2px;
}
#footer {
color: #114411;
border-color: #7d2717;
}

11. UseUse
- Download: http://lesscss.org/
- <link rel="stylesheet/less" type="text/css" href="styles.less">
<script src="less.js" type="text/javascript"></script>