In Article by Barrett Palmer July 13, 2014

LESS-CSS

LESS, extending the CSS language.

LESS was created in 2009 by Alexis Sellier, more commonly known as @cloudhead. Originally written in Ruby, it was then ported to JavaScript.

As an extension to CSS, LESS is not only backwards compatible with CSS, but the extra features it adds use existing CSS syntax.

Example:

@base: #f938ab;

.box-shadow(@style, @c) when (iscolor(@c)) {
  -webkit-box-shadow: @style @c;
  box-shadow:         @style @c;
}
.box-shadow(@style, @alpha: 50%) when (isnumber(@alpha)) {
  .box-shadow(@style, rgba(0, 0, 0, @alpha));
}
.box {
  color: saturate(@base, 5%);
  border-color: lighten(@base, 30%);
  div { .box-shadow(0 0 5px, 30%) }
}

@base: #f938ab;

.box-shadow(@style, @c) when (iscolor(@c)) {

-webkit-box-shadow: @style @c;

box-shadow: @style @c;

}

.box-shadow(@style, @alpha: 50%) when (isnumber(@alpha)) {

.box-shadow(@style, rgba(0, 0, 0, @alpha));

}

.box {

color: saturate(@base, 5%);

border-color: lighten(@base, 30%);

div { .box-shadow(0 0 5px, 30%) }

}

Will compile to:

.box {
  color: #fe33ac;
  border-color: #fdcdea;
}
.box div {
  -webkit-box-shadow: 0 0 5px rgba(0, 0, 0, 0.3);
  box-shadow: 0 0 5px rgba(0, 0, 0, 0.3);
}