CodeMirror: LESS mode

@media screen and (device-aspect-ratio: 16/9) { … }
@media screen and (device-aspect-ratio: 32/18) { … }
@media screen and (device-aspect-ratio: 1280/720) { … }
@media screen and (device-aspect-ratio: 2560/1440) { … }

html:lang(fr-be)
html:lang(de)
:lang(fr-be) > q
:lang(de) > q

tr:nth-child(2n+1) /* represents every odd row of an HTML table */
tr:nth-child(odd)  /* same */
tr:nth-child(2n+0) /* represents every even row of an HTML table */
tr:nth-child(even) /* same */

/* Alternate paragraph colours in CSS */
p:nth-child(4n+1) { color: navy; }
p:nth-child(4n+2) { color: green; }
p:nth-child(4n+3) { color: maroon; }
p:nth-child(4n+4) { color: purple; }

:nth-child(10n-1)  /* represents the 9th, 19th, 29th, etc, element */
:nth-child(10n+9)  /* Same */
:nth-child(10n+-1) /* Syntactically invalid, and would be ignored */

:nth-child( 3n + 1 )
:nth-child( +3n - 2 )
:nth-child( -n+ 6)
:nth-child( +6 )

html|tr:nth-child(-n+6)  /* represents the 6 first rows of XHTML tables */

img:nth-of-type(2n+1) { float: right; }
img:nth-of-type(2n) { float: left; }

body > h2:nth-of-type(n+2):nth-last-of-type(n+2)
body > h2:not(:first-of-type):not(:last-of-type)

html|*:not(:link):not(:visited)
*|*:not(:hover)
p::first-line { text-transform: uppercase }

p { color: red; font-size: 12pt }
p::first-letter { color: green; font-size: 200% }
p::first-line { color: blue }

p { line-height: 1.1 }
p::first-letter { font-size: 3em; font-weight: normal }
span { font-weight: bold }

*               /* a=0 b=0 c=0 -> specificity =   0 */
LI              /* a=0 b=0 c=1 -> specificity =   1 */
UL LI           /* a=0 b=0 c=2 -> specificity =   2 */
UL OL+LI        /* a=0 b=0 c=3 -> specificity =   3 */
H1 + *[REL=up]  /* a=0 b=1 c=1 -> specificity =  11 */
UL OL LI.red    /* a=0 b=1 c=3 -> specificity =  13 */
LI.red.level    /* a=0 b=2 c=1 -> specificity =  21 */
#x34y           /* a=1 b=0 c=0 -> specificity = 100 */
#s12:not(FOO)   /* a=1 b=0 c=1 -> specificity = 101 */

@namespace foo url(http://www.example.com);
foo|h1 { color: blue }  /* first rule */
foo|* { color: yellow } /* second rule */
|h1 { color: red }      /* ...*/
*|h1 { color: green }
h1 { color: green }

span[hello="Ocean"][goodbye="Land"]

a[rel~="copyright"] { ... }
a[href="http://www.w3.org/"] { ... }

DIALOGUE[character=romeo]
DIALOGUE[character=juliet]

[att^=val]
[att$=val]
[att*=val]

@namespace foo "http://www.example.com";
[foo|att=val] { color: blue }
[*|att] { color: yellow }
[|att] { color: green }
[att] { color: green }

*:target { color : red }
*:target::before { content : url(target.png) }

E[foo]{
  padding:65px;
}
E[foo] ~ F{
  padding:65px;
}
E#myid{
  padding:65px;
}
input[type="search"]::-webkit-search-decoration,
input[type="search"]::-webkit-search-cancel-button {
  -webkit-appearance: none; // Inner-padding issues in Chrome OSX, Safari 5
}
button::-moz-focus-inner,
input::-moz-focus-inner { // Inner padding and border oddities in FF3/4
  padding: 0;
  border: 0;
}
.btn {
  // reset here as of 2.0.3 due to Recess property order
  border-color: #ccc;
  border-color: rgba(0,0,0,.1) rgba(0,0,0,.1) rgba(0,0,0,.25);
}
fieldset span button, fieldset span input[type="file"] {
  font-size:12px;
	font-family:Arial, Helvetica, sans-serif;
}
.el tr:nth-child(even):last-child td:first-child{
	-moz-border-radius-bottomleft:3px;
	-webkit-border-bottom-left-radius:3px;
	border-bottom-left-radius:3px;
}

/* Some LESS code */

button {
    width:  32px;
    height: 32px;
    border: 0;
    margin: 4px;
    cursor: pointer;
}
button.icon-plus { background: url(http://dahlström.net/tmp/sharp-icons/svg-icon-target.svg#plus) no-repeat; }
button.icon-chart { background: url(http://dahlström.net/tmp/sharp-icons/svg-icon-target.svg#chart) no-repeat; }

button:hover { background-color: #999; }
button:active { background-color: #666; }

@test_a: #eeeQQQ;//this is not a valid hex value and thus parsed as an element id
@test_b: #eeeFFF //this is a valid hex value but the declaration doesn't end with a semicolon and thus parsed as an element id

#eee aaa .box
{
  #test bbb {
    width: 500px;
    height: 250px;
    background-image: url(dir/output/sheep.png), url( betweengrassandsky.png );
    background-position: center bottom, left top;
    background-repeat: no-repeat;
  }
}

@base: #f938ab;

.box-shadow(@style, @c) when (iscolor(@c)) {
  box-shadow:         @style @c;
  -webkit-box-shadow: @style @c;
  -moz-box-shadow:    @style @c;
}
.box-shadow(@style, @alpha: 50%) when (isnumber(@alpha)) {
  .box-shadow(@style, rgba(0, 0, 0, @alpha));
}

@color: #4D926F;

#header {
  color: @color;
  color: #000000;
}
h2 {
  color: @color;
}

.rounded-corners (@radius: 5px) {
  border-radius: @radius;
  -webkit-border-radius: @radius;
  -moz-border-radius: @radius;
}

#header {
  .rounded-corners;
}
#footer {
  .rounded-corners(10px);
}

.box-shadow (@x: 0, @y: 0, @blur: 1px, @alpha) {
  @val: @x @y @blur rgba(0, 0, 0, @alpha);

box-shadow:         @val;
  -webkit-box-shadow: @val;
  -moz-box-shadow:    @val;
}
.box { @base: #f938ab;
  color:        saturate(@base, 5%);
  border-color: lighten(@base, 30%);
  div { .box-shadow(0, 0, 5px, 0.4) }
}

@import url("something.css");

@light-blue:   hsl(190, 50%, 65%);
@light-yellow: desaturate(#fefec8, 10%);
@dark-yellow:  desaturate(darken(@light-yellow, 10%), 40%);
@darkest:      hsl(20, 0%, 15%);
@dark:         hsl(190, 20%, 30%);
@medium:       hsl(10, 60%, 30%);
@light:        hsl(90, 40%, 20%);
@lightest:     hsl(90, 20%, 90%);
@highlight:    hsl(80, 50%, 90%);
@blue:         hsl(210, 60%, 20%);
@alpha-blue:   hsla(210, 60%, 40%, 0.5);

.box-shadow (@x, @y, @blur, @alpha) {
  @value: @x @y @blur rgba(0, 0, 0, @alpha);
  box-shadow:         @value;
  -moz-box-shadow:    @value;
  -webkit-box-shadow: @value;
}
.border-radius (@radius) {
  border-radius: @radius;
  -moz-border-radius: @radius;
  -webkit-border-radius: @radius;
}

.border-radius (@radius, bottom) {
  border-top-right-radius: 0;
  border-top-left-radius: 0;
  -moz-border-top-right-radius: 0;
  -moz-border-top-left-radius: 0;
  -webkit-border-top-left-radius: 0;
  -webkit-border-top-right-radius: 0;
}
.border-radius (@radius, right) {
  border-bottom-left-radius: 0;
  border-top-left-radius: 0;
  -moz-border-bottom-left-radius: 0;
  -moz-border-top-left-radius: 0;
  -webkit-border-bottom-left-radius: 0;
  -webkit-border-top-left-radius: 0;
}
.box-shadow-inset (@x, @y, @blur, @color) {
  box-shadow: @x @y @blur @color inset;
  -moz-box-shadow: @x @y @blur @color inset;
  -webkit-box-shadow: @x @y @blur @color inset;
}
.code () {
  font-family: 'Bitstream Vera Sans Mono',
               'DejaVu Sans Mono',
               'Monaco',
               Courier,
               monospace !important;
}
.wrap () {
  text-wrap: wrap;
  white-space: pre-wrap;       /* css-3 */
  white-space: -moz-pre-wrap;  /* Mozilla, since 1999 */
  white-space: -pre-wrap;      /* Opera 4-6 */
  white-space: -o-pre-wrap;    /* Opera 7 */
  word-wrap: break-word;       /* Internet Explorer 5.5+ */
}

html { margin: 0 }
body {
  background-color: @darkest;
  margin: 0 auto;
  font-family: Arial, sans-serif;
  font-size: 100%;
  overflow-x: hidden;
}
nav, header, footer, section, article {
  display: block;
}
a {
  color: #b83000;
}
h1 a {
  color: black;
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}
h1, h2, h3, h4 {
  margin: 0;
  font-weight: normal;
}
ul, li {
  list-style-type: none;
}
code { .code; }
code {
  .string, .regexp { color: @dark }
  .keyword { font-weight: bold }
  .comment { color: rgba(0, 0, 0, 0.5) }
  .number { color: @blue }
  .class, .special { color: rgba(0, 50, 100, 0.8) }
}
pre {
  padding: 0 30px;
  .wrap;
}
blockquote {
  font-style: italic;
}
body > footer {
  text-align: left;
  margin-left: 10px;
  font-style: italic;
  font-size: 18px;
  color: #888;
}

#logo {
  margin-top: 30px;
  margin-bottom: 30px;
  display: block;
  width: 199px;
  height: 81px;
  background: url(/images/logo.png) no-repeat;
}
nav {
  margin-left: 15px;
}
nav a, #dropdown li {
  display: inline-block;
  color: white;
  line-height: 42px;
  margin: 0;
  padding: 0px 15px;
  text-shadow: -1px -1px 1px rgba(0, 0, 0, 0.5);
  text-decoration: none;
  border: 2px solid transparent;
  border-width: 0 2px;
  &:hover {
    .dark-red; 
    text-decoration: none;
  }
}
.dark-red {
    @red: @medium;
    border: 2px solid darken(@red, 25%);
    border-left-color: darken(@red, 15%);
    border-right-color: darken(@red, 15%);
    border-bottom: 0;
    border-top: 0;
    background-color: darken(@red, 10%);
}

.content {
  margin: 0 auto;
  width: 980px;
}

#menu {
  position: absolute;
  width: 100%;
  z-index: 3;
  clear: both;
  display: block;
  background-color: @blue;
  height: 42px;
  border-top: 2px solid lighten(@alpha-blue, 20%);
  border-bottom: 2px solid darken(@alpha-blue, 25%);
  .box-shadow(0, 1px, 8px, 0.6);
  -moz-box-shadow: 0 0 0 #000; // Because firefox sucks.

&.docked {
    background-color: hsla(210, 60%, 40%, 0.4);
  }
  &:hover {
    background-color: @blue;
  }

#dropdown {
    margin: 0 0 0 117px;
    padding: 0;
    padding-top: 5px;
    display: none;
    width: 190px;
    border-top: 2px solid @medium;
    color: @highlight;
    border: 2px solid darken(@medium, 25%);
    border-left-color: darken(@medium, 15%);
    border-right-color: darken(@medium, 15%);
    border-top-width: 0;
    background-color: darken(@medium, 10%);
    ul {
      padding: 0px;  
    }
    li {
      font-size: 14px;
      display: block;
      text-align: left;
      padding: 0;
      border: 0;
      a {
        display: block;
        padding: 0px 15px;  
        text-decoration: none;
        color: white;  
        &:hover {
          background-color: darken(@medium, 15%);
          text-decoration: none;
        }
      }
    }
    .border-radius(5px, bottom);
    .box-shadow(0, 6px, 8px, 0.5);
  }
}

#main {
  margin: 0 auto;
  width: 100%;
  background-color: @light-blue;
  border-top: 8px solid darken(@light-blue, 5%);

#intro {
    background-color: lighten(@light-blue, 25%);
    float: left;
    margin-top: -8px;
    margin-right: 5px;

height: 380px;
    position: relative;
    z-index: 2;
    font-family: 'Droid Serif', 'Georgia';
    width: 395px;
    padding: 45px 20px 23px 30px;
    border: 2px dashed darken(@light-blue, 10%);
    .box-shadow(1px, 0px, 6px, 0.5);
    border-bottom: 0;
    border-top: 0;
    #download { color: transparent; border: 0; float: left; display: inline-block; margin: 15px 0 15px -5px; }
    #download img { display: inline-block}
    #download-info {
      code {
        font-size: 13px;  
      }
      color: @blue + #333; display: inline; float: left; margin: 36px 0 0 15px }
  }
  h2 {
    span {
      color: @medium;  
    }
    color: @blue;
    margin: 20px 0;
    font-size: 24px;
    line-height: 1.2em;
  }
  h3 {
    color: @blue;
    line-height: 1.4em;
    margin: 30px 0 15px 0;
    font-size: 1em;
    text-shadow: 0px 0px 0px @lightest;
    span { color: @medium }
  }
  #example {
    p {
      font-size: 18px;
      color: @blue;
      font-weight: bold;
      text-shadow: 0px 1px 1px @lightest;
    }
    pre {
      margin: 0;
      text-shadow: 0 -1px 1px @darkest;
      margin-top: 20px;
      background-color: desaturate(@darkest, 8%);
      border: 0;
      width: 450px;
      color: lighten(@lightest, 2%);
      background-repeat: repeat;
      padding: 15px;
      border: 1px dashed @lightest;
      line-height: 15px;
      .box-shadow(0, 0px, 15px, 0.5);
      .code;
      .border-radius(2px);
      code .attribute { color: hsl(40, 50%, 70%) }
      code .variable  { color: hsl(120, 10%, 50%) }
      code .element   { color: hsl(170, 20%, 50%) }

.page {
  .content {
    width: 870px;
    padding: 45px;
  }
  margin: 0 auto;
  font-family: 'Georgia', serif;
  font-size: 18px;
  line-height: 26px;
  padding: 0 60px;
  code {
    font-size: 16px;  
  }
  pre {
    border-width: 1px;
    border-style: dashed;
    padding: 15px;
    margin: 15px 0;
  }
  h1 {
    text-align: left;
    font-size: 40px;
    margin-top: 15px;
    margin-bottom: 35px;
  }
  p + h1 { margin-top: 60px }
  h2, h3 {
    margin: 30px 0 15px 0;
  }
  p + h2, pre + h2, code + h2 {
    border-top: 6px solid rgba(255, 255, 255, 0.1);
    padding-top: 30px;
  }
  h3 {
    margin: 15px 0;
  }
}

#docs {
  @bg: lighten(@light-blue, 5%);
  border-top: 2px solid lighten(@bg, 5%);
  color: @blue;
  background-color: @light-blue;
  .box-shadow(0, -2px, 5px, 0.2);

h1 {
    font-family: 'Droid Serif', 'Georgia', serif;
    padding-top: 30px;
    padding-left: 45px;
    font-size: 44px;
    text-align: left;
    margin: 30px 0 !important;
    text-shadow: 0px 1px 1px @lightest;
    font-weight: bold;
  }
  .content {
    clear: both;
    border-color: transparent;
    background-color: lighten(@light-blue, 25%);
    .box-shadow(0, 5px, 5px, 0.4);
  }
  pre {
    @background: lighten(@bg, 30%);
    color: lighten(@blue, 10%);
    background-color: @background;
    border-color: lighten(@light-blue, 25%);
    border-width: 2px;
    code .attribute { color: hsl(40, 50%, 30%) }
    code .variable  { color: hsl(120, 10%, 30%) }
    code .element   { color: hsl(170, 20%, 30%) }

code .string, .regexp { color: hsl(75, 50%, 35%) }
    code .class { color: hsl(40, 40%, 30%); font-weight: normal }
    code .id { color: hsl(50, 40%, 30%); font-weight: normal }
    code .comment { color: rgba(0, 0, 0, 0.4) }
    code .number, .color { color: hsl(10, 40%, 30%) }
    code .class, code .mixin, .special { color: hsl(190, 20%, 30%) }
  }
  pre code                    { font-size: 15px  }
  p + h2, pre + h2, code + h2 { border-top-color: rgba(0, 0, 0, 0.1) }
}

td {
  padding-right: 30px;  
}
#synopsis {
  .box-shadow(0, 5px, 5px, 0.2);
}
#synopsis, #about {
  h2 {
    font-size: 30px;  
    padding: 10px 0;
  }
  h1 + h2 {
      margin-top: 15px;  
  }
  h3 { font-size: 22px }

.code-example {
    border-spacing: 0;
    border-width: 1px;
    border-style: dashed;
    padding: 0;
    pre { border: 0; margin: 0 }
    td {
      border: 0;
      margin: 0;
      background-color: desaturate(darken(@darkest, 5%), 20%);
      vertical-align: top;
      padding: 0;
    }
    tr { padding: 0 }
  }
  .css-output {
    td {
      border-left: 0;  
    }
  }
  .less-example {
    //border-right: 1px dotted rgba(255, 255, 255, 0.5) !important;
  }
  .css-output, .less-example {
    width: 390px;
  }
  pre {
    padding: 20px;
    line-height: 20px;
    font-size: 14px;
  }
}
#about, #synopsis, #guide {
  a {
    text-decoration: none;
    color: @light-yellow;
    border-bottom: 1px dashed rgba(255, 255, 255, 0.2);
    &:hover {
      text-decoration: none;
      border-bottom: 1px dashed @light-yellow;
    }
  }
  @bg: desaturate(darken(@darkest, 5%), 20%);
  text-shadow: 0 -1px 1px lighten(@bg, 5%);
  color: @highlight;
  background-color: @bg;
  .content {
    background-color: desaturate(@darkest, 20%);
    clear: both;
    .box-shadow(0, 5px, 5px, 0.4);
  }
  h1, h2, h3 {
    color: @dark-yellow;
  }
  pre {
      code .attribute { color: hsl(40, 50%, 70%) }
      code .variable  { color: hsl(120, 10%, 50%) }
      code .element   { color: hsl(170, 20%, 50%) }

code .string, .regexp { color: hsl(75, 50%, 65%) }
      code .class { color: hsl(40, 40%, 60%); font-weight: normal }
      code .id { color: hsl(50, 40%, 60%); font-weight: normal }
      code .comment { color: rgba(255, 255, 255, 0.2) }
      code .number, .color { color: hsl(10, 40%, 50%) }
      code .class, code .mixin, .special { color: hsl(190, 20%, 50%) }
    background-color: @bg;
    border-color: darken(@light-yellow, 5%);
  }
  code {
    color: darken(@dark-yellow, 5%);
    .string, .regexp { color: desaturate(@light-blue, 15%) }
    .keyword { color: hsl(40, 40%, 60%); font-weight: normal }
    .comment { color: rgba(255, 255, 255, 0.2) }
    .number { color: lighten(@blue, 10%) }
    .class, .special { color: hsl(190, 20%, 50%) }
  }
}
#guide {
  background-color: @darkest;
  .content {
    background-color: transparent;
  }

}

#about {
  background-color: @darkest !important;
  .content {
    background-color: desaturate(lighten(@darkest, 3%), 5%);
  }
}
#synopsis {
  background-color: desaturate(lighten(@darkest, 3%), 5%) !important;
  .content {
    background-color: desaturate(lighten(@darkest, 3%), 5%);
  }
  pre {}
}
#synopsis, #guide {
  .content {
    .box-shadow(0, 0px, 0px, 0.0);
  }
}
#about footer {
  margin-top: 30px;
  padding-top: 30px;
  border-top: 6px solid rgba(0, 0, 0, 0.1);
  text-align: center;
  font-size: 16px;
  color: rgba(255, 255, 255, 0.35);
  #copy { font-size: 12px }
  text-shadow: -1px -1px 1px rgba(0, 0, 0, 0.02);
}

MIME types defined: text/x-less, text/css (if not previously defined).