Bootstrap/less/mixins.less

// Mixins.less
// Snippets of reusable CSS to develop faster and keep code readable
// -----------------------------------------------------------------


// UTILITY MIXINS
// --------------------------------------------------

// Clearfix
// --------
// For clearing floats like a boss h5bp.com/q
.clearfix() {
  *zoom: 1;
  &:before,
  &:after {
    display: table;
    content: "";
  }
  &:after {
    clear: both;
  }
}

// Webkit-style focus
// ------------------
.tab-focus() {
  // Default
  outline: thin dotted;
  // Webkit
  outline: 5px auto -webkit-focus-ring-color;
  outline-offset: -2px;
}

// Center-align a block level element
// ----------------------------------
.center-block() {
  display: block;
  margin-left: auto;
  margin-right: auto;
}

// IE7 inline-block
// ----------------
.ie7-inline-block() {
  *display: inline; /* IE7 inline-block hack */
  *zoom: 1;
}

// IE7 likes to collapse whitespace on either side of the inline-block elements.
// Ems because we're attempting to match the width of a space character. Left
// version is for form buttons, which typically come after other elements, and
// right version is for icons, which come before. Applying both is ok, but it will
// mean that space between those elements will be .6em (~2 space characters) in IE7,
// instead of the 1 space in other browsers.
.ie7-restore-left-whitespace() {
  *margin-left: .3em;

  &:first-child {
    *margin-left: 0;
  }
}

.ie7-restore-right-whitespace() {
  *margin-right: .3em;

  &:last-child {
    *margin-left: 0;
  }
}

// Sizing shortcuts
// -------------------------
.size(@height: 5px, @width: 5px) {
  width: @width;
  height: @height;
}
.square(@size: 5px) {
  .size(@size, @size);
}

// Placeholder text
// -------------------------
.placeholder(@color: @placeholderText) {
  :-moz-placeholder {
    color: @color;
  }
  ::-webkit-input-placeholder {
    color: @color;
  }
}



// FONTS
// --------------------------------------------------

#font {
  #family {
    .serif() {
      font-family: Georgia, "Times New Roman", Times, serif;
    }
    .sans-serif() {
      font-family: "Helvetica Neue", Helvetica, Arial, sans-serif;
    }
    .monospace() {
      font-family: Menlo, Monaco, "Courier New", monospace;
    }
  }
  .shorthand(@size: @baseFontSize, @weight: normal, @lineHeight: @baseLineHeight) {
    font-size: @size;
    font-weight: @weight;
    line-height: @lineHeight;
  }
  .serif(@size: @baseFontSize, @weight: normal, @lineHeight: @baseLineHeight) {
    #font > #family > .serif;
    #font > .shorthand(@size, @weight, @lineHeight);
  }
  .sans-serif(@size: @baseFontSize, @weight: normal, @lineHeight: @baseLineHeight) {
    #font > #family > .sans-serif;
    #font > .shorthand(@size, @weight, @lineHeight);
  }
  .monospace(@size: @baseFontSize, @weight: normal, @lineHeight: @baseLineHeight) {
    #font > #family > .monospace;
    #font > .shorthand(@size, @weight, @lineHeight);
  }
}



// GRID SYSTEM
// --------------------------------------------------

// Site container
// -------------------------
.container-fixed() {
  width: @siteWidth;
  margin-left: auto;
  margin-right: auto;
  .clearfix();
}

// Columns and offseting
// -------------------------
.columns(@columns: 1) {
  width: (@gridColumnWidth * @columns) + (@gridGutterWidth * (@columns - 1));
}
.offset(@columns: 1) {
  margin-left: (@gridColumnWidth * @columns) + (@gridGutterWidth * (@columns - 1)) + (@gridGutterWidth * 2);
}
// Necessary grid styles for every column to make them appear next to each other horizontally
.gridColumn() {
  float: left;
  margin-left: @gridGutterWidth;
}
// makeColumn can be used to mark any element (e.g., .content-primary) as a column without changing markup to .span something
.makeColumn(@columnSpan: 1) {
  .gridColumn();
  .columns(@columnSpan);
}



// CSS3 PROPERTIES
// --------------------------------------------------

// Border Radius
.border-radius(@radius: 5px) {
  -webkit-border-radius: @radius;
     -moz-border-radius: @radius;
          border-radius: @radius;
}

// Drop shadows
.box-shadow(@shadow: 0 1px 3px rgba(0,0,0,.25)) {
  -webkit-box-shadow: @shadow;
     -moz-box-shadow: @shadow;
          box-shadow: @shadow;
}

// Transitions
.transition(@transition) {
  -webkit-transition: @transition;
     -moz-transition: @transition;
      -ms-transition: @transition;
       -o-transition: @transition;
          transition: @transition;
}

// Transformations
.rotate(@degrees) {
  -webkit-transform: rotate(@degrees);
     -moz-transform: rotate(@degrees);
      -ms-transform: rotate(@degrees);
       -o-transform: rotate(@degrees);
          transform: rotate(@degrees);
}
.scale(@ratio) {
  -webkit-transform: scale(@ratio);
     -moz-transform: scale(@ratio);
      -ms-transform: scale(@ratio);
       -o-transform: scale(@ratio);
          transform: scale(@ratio);
}
.translate(@x: 0, @y: 0) {
  -webkit-transform: translate(@x, @y);
     -moz-transform: translate(@x, @y);
      -ms-transform: translate(@x, @y);
       -o-transform: translate(@x, @y);
          transform: translate(@x, @y);
}

// Background clipping
// Heads up: FF 3.6 and under need "padding" instead of "padding-box"
.background-clip(@clip) {
  -webkit-background-clip: @clip;
     -moz-background-clip: @clip;
          background-clip: @clip;
}

// Background sizing
.background-size(@size){
  -webkit-background-size: @size;
     -moz-background-size: @size;
       -o-background-size: @size;
          background-size: @size;
}


// Box sizing
.box-sizing(@boxmodel) {
  -webkit-box-sizing: @boxmodel;
     -moz-box-sizing: @boxmodel;
          box-sizing: @boxmodel;
}

// User select
// For selecting text on the page
.user-select(@select) {
  -webkit-user-select: @select;
     -moz-user-select: @select;
       -o-user-select: @select;
          user-select: @select;
}

// Resize anything
.resizable(@direction: both) {
  resize: @direction; // Options: horizontal, vertical, both
  overflow: auto; // Safari fix
}

// CSS3 Content Columns
.content-columns(@columnCount, @columnGap: @gridColumnGutter) {
  -webkit-column-count: @columnCount;
     -moz-column-count: @columnCount;
          column-count: @columnCount;
  -webkit-column-gap: @columnGap;
     -moz-column-gap: @columnGap;
          column-gap: @columnGap;
}

// Opacity
.opacity(@opacity: 100) {
  opacity: @opacity / 100;
   filter: e(%("alpha(opacity=%d)", @opacity));
}



// BACKGROUNDS
// --------------------------------------------------

// Add an alphatransparency value to any background or border color (via Elyse Holladay)
#translucent {
  .background(@color: @white, @alpha: 1) {
    background-color: hsla(hue(@color), saturation(@color), lightness(@color), @alpha);
  }
  .border(@color: @white, @alpha: 1) {
    border-color: hsla(hue(@color), saturation(@color), lightness(@color), @alpha);
    .background-clip(padding-box);
  }
}

// Gradient Bar Colors for buttons and alerts
.gradientBar(@primaryColor, @secondaryColor) {
  #gradient > .vertical(@primaryColor, @secondaryColor);
  border-color: @secondaryColor @secondaryColor darken(@secondaryColor, 15%);
  border-color: rgba(0,0,0,.1) rgba(0,0,0,.1) fadein(rgba(0,0,0,.1), 15%);
}

// Gradients
#gradient {
  .horizontal(@startColor: #555, @endColor: #333) {
    background-color: @endColor;
    background-image: -moz-linear-gradient(left, @startColor, @endColor); // FF 3.6+
    background-image: -ms-linear-gradient(left, @startColor, @endColor); // IE10
    background-image: -webkit-gradient(linear, 0 0, 100% 0, from(@startColor), to(@endColor)); // Safari 4+, Chrome 2+
    background-image: -webkit-linear-gradient(left, @startColor, @endColor); // Safari 5.1+, Chrome 10+
    background-image: -o-linear-gradient(left, @startColor, @endColor); // Opera 11.10
    background-image: linear-gradient(left, @startColor, @endColor); // Le standard
    background-repeat: repeat-x;
  }
  .vertical(@startColor: #555, @endColor: #333) {
    background-color: mix(@startColor, @endColor, 60%);
    background-image: -moz-linear-gradient(top, @startColor, @endColor); // FF 3.6+
    background-image: -ms-linear-gradient(top, @startColor, @endColor); // IE10
    background-image: -webkit-gradient(linear, 0 0, 0 100%, from(@startColor), to(@endColor)); // Safari 4+, Chrome 2+
    background-image: -webkit-linear-gradient(top, @startColor, @endColor); // Safari 5.1+, Chrome 10+
    background-image: -o-linear-gradient(top, @startColor, @endColor); // Opera 11.10
    background-image: linear-gradient(top, @startColor, @endColor); // The standard
    background-repeat: repeat-x;
  }
  .directional(@startColor: #555, @endColor: #333, @deg: 45deg) {
    background-color: @endColor;
    background-repeat: repeat-x;
    background-image: -moz-linear-gradient(@deg, @startColor, @endColor); // FF 3.6+
    background-image: -ms-linear-gradient(@deg, @startColor, @endColor); // IE10
    background-image: -webkit-linear-gradient(@deg, @startColor, @endColor); // Safari 5.1+, Chrome 10+
    background-image: -o-linear-gradient(@deg, @startColor, @endColor); // Opera 11.10
    background-image: linear-gradient(@deg, @startColor, @endColor); // The standard
  }
  .vertical-three-colors(@startColor: #00b3ee, @midColor: #7a43b6, @colorStop: 50%, @endColor: #c3325f) {
    background-color: mix(@midColor, @endColor, 80%);
    background-image: -webkit-gradient(linear, 0 0, 0 100%, from(@startColor), color-stop(@colorStop, @midColor), to(@endColor));
    background-image: -webkit-linear-gradient(@startColor, @midColor @colorStop, @endColor);
    background-image: -moz-linear-gradient(top, @startColor, @midColor @colorStop, @endColor);
    background-image: -ms-linear-gradient(@startColor, @midColor @colorStop, @endColor);
    background-image: -o-linear-gradient(@startColor, @midColor @colorStop, @endColor);
    background-image: linear-gradient(@startColor, @midColor @colorStop, @endColor);
    background-repeat: no-repeat;
  }
  .radial(@innerColor: #555, @outerColor: #333)  {
    background-color: @outerColor;
    background-image: -webkit-gradient(radial, center center, 0, center center, 460, from(@innerColor), to(@outerColor));
    background-image: -webkit-radial-gradient(circle, @innerColor, @outerColor);
    background-image: -moz-radial-gradient(circle, @innerColor, @outerColor);
    background-image: -ms-radial-gradient(circle, @innerColor, @outerColor);
    background-repeat: no-repeat;
    // Opera cannot do radial gradients yet
  }
  .striped(@color, @angle: -45deg) {
    background-color: @color;
    background-image: -webkit-gradient(linear, 0 100%, 100% 0, color-stop(.25, rgba(255,255,255,.15)), color-stop(.25, transparent), color-stop(.5, transparent), color-stop(.5, rgba(255,255,255,.15)), color-stop(.75, rgba(255,255,255,.15)), color-stop(.75, transparent), to(transparent));
    background-image: -webkit-linear-gradient(@angle, rgba(255,255,255,.15) 25%, transparent 25%, transparent 50%, rgba(255,255,255,.15) 50%, rgba(255,255,255,.15) 75%, transparent 75%, transparent);
    background-image: -moz-linear-gradient(@angle, rgba(255,255,255,.15) 25%, transparent 25%, transparent 50%, rgba(255,255,255,.15) 50%, rgba(255,255,255,.15) 75%, transparent 75%, transparent);
    background-image: -ms-linear-gradient(@angle, rgba(255,255,255,.15) 25%, transparent 25%, transparent 50%, rgba(255,255,255,.15) 50%, rgba(255,255,255,.15) 75%, transparent 75%, transparent);
    background-image: -o-linear-gradient(@angle, rgba(255,255,255,.15) 25%, transparent 25%, transparent 50%, rgba(255,255,255,.15) 50%, rgba(255,255,255,.15) 75%, transparent 75%, transparent);
    background-image: linear-gradient(@angle, rgba(255,255,255,.15) 25%, transparent 25%, transparent 50%, rgba(255,255,255,.15) 50%, rgba(255,255,255,.15) 75%, transparent 75%, transparent);
  }
}


// Mixin for generating button backgrounds
// ---------------------------------------
.buttonBackground(@startColor, @endColor) {
  // gradientBar will set the background to a pleasing blend of these, to support IE<=9
  .gradientBar(@startColor, @endColor);

  // in these cases the gradient won't cover the background, so we override
  &:hover, &:active, &.active, &.disabled, &[disabled] {
    background-color: @endColor;
  }

  // IE 7 + 8 can't handle box-shadow to show active, so we darken a bit ourselves
  &:active,
  &.active {
    background-color: darken(@endColor, 10%) e("\9");
  }
}


// COMPONENT MIXINS
// --------------------------------------------------

// POPOVER ARROWS
// -------------------------
// For tipsies and popovers
#popoverArrow {
  .top(@arrowWidth: 5px) {
    bottom: 0;
    left: 50%;
    margin-left: -@arrowWidth;
    border-left: @arrowWidth solid transparent;
    border-right: @arrowWidth solid transparent;
    border-top: @arrowWidth solid @black;
  }
  .left(@arrowWidth: 5px) {
    top: 50%;
    right: 0;
    margin-top: -@arrowWidth;
    border-top: @arrowWidth solid transparent;
    border-bottom: @arrowWidth solid transparent;
    border-left: @arrowWidth solid @black;
  }
  .bottom(@arrowWidth: 5px) {
    top: 0;
    left: 50%;
    margin-left: -@arrowWidth;
    border-left: @arrowWidth solid transparent;
    border-right: @arrowWidth solid transparent;
    border-bottom: @arrowWidth solid @black;
  }
  .right(@arrowWidth: 5px) {
    top: 50%;
    left: 0;
    margin-top: -@arrowWidth;
    border-top: @arrowWidth solid transparent;
    border-bottom: @arrowWidth solid transparent;
    border-right: @arrowWidth solid @black;
  }
}