balkian.github.com/font-awesome/scss/_core.scss

/* FONT AWESOME CORE
 * -------------------------- */

[class^="icon-"],
[class*=" icon-"] {
  @include icon-FontAwesome();
}

[class^="icon-"]:before,
[class*=" icon-"]:before {
  text-decoration: inherit;
  display: inline-block;
  speak: none;
}

/* makes the font 33% larger relative to the icon container */
.icon-large:before {
  vertical-align: -10%;
  font-size: (4em/3);
}

/* makes sure icons active on rollover in links */
a {
  [class^="icon-"],
  [class*=" icon-"] {
    display: inline;
  }
}

/* increased font size for icon-large */
[class^="icon-"],
[class*=" icon-"] {
  &.icon-fixed-width {
    display: inline-block;
    width: (16em/14);
    text-align: right;
    padding-right: (4em/14);
    &.icon-large {
      width: (20em/14);
    }
  }
}

.icons-ul {
  margin-left: $icons-li-width;
  list-style-type: none;

  > li { position: relative; }

  .icon-li {
    position: absolute;
    left: -$icons-li-width;
    width: $icons-li-width;
    text-align: center;
    line-height: inherit;
  }
}

// allows usage of the hide class directly on font awesome icons
[class^="icon-"],
[class*=" icon-"] {
  &.hide {
    display: none;
  }
}

.icon-muted { color: $iconMuted; }
.icon-light { color: $iconLight; }
.icon-dark { color: $iconDark; }

// Icon Borders
// -------------------------

.icon-border {
  border: solid 1px $borderColor;
  padding: .2em .25em .15em;
  @include border-radius(3px);
}

// Icon Sizes
// -------------------------

.icon-2x {
  font-size: 2em;
  &.icon-border {
    border-width: 2px;
    @include border-radius(4px);
  }
}
.icon-3x {
  font-size: 3em;
  &.icon-border {
    border-width: 3px;
    @include border-radius(5px);
  }
}
.icon-4x {
  font-size: 4em;
  &.icon-border {
    border-width: 4px;
    @include border-radius(6px);
  }
}

.icon-5x {
  font-size: 5em;
  &.icon-border {
    border-width: 5px;
    @include border-radius(7px);
  }
}


// Floats & Margins
// -------------------------

// Quick floats
.pull-right { float: right; }
.pull-left { float: left; }

[class^="icon-"],
[class*=" icon-"] {
  &.pull-left {
    margin-right: .3em;
  }
  &.pull-right {
    margin-left: .3em;
  }
}