modified buttons.less/bootstrap supporting the buttons as mixins

buttons.less

// BUTTON STYLES
// -------------


// Base styles
// --------------------------------------------------

// Core
.btn {
  display: inline-block;
  .ie7-inline-block();
  padding: 4px 10px 4px;
  margin-bottom: 0; // For input.btn
  font-size: @baseFontSize;
  line-height: @baseLineHeight;
  color: @grayDark;
  text-align: center;
  text-shadow: 0 1px 1px rgba(255,255,255,.75);
  vertical-align: middle;
  .buttonBackground(@btnBackground, @btnBackgroundHighlight);
  border: 1px solid @btnBorder;
  border-bottom-color: darken(@btnBorder, 10%);
  .border-radius(4px);
  @shadow: inset 0 1px 0 rgba(255,255,255,.2), 0 1px 2px rgba(0,0,0,.05);
  .box-shadow(@shadow);
  cursor: pointer;

  // Give IE7 some love
  .ie7-restore-left-whitespace();

  // Hover state
  &:hover {
    color: @grayDark;
    text-decoration: none;
    background-color: darken(@white, 10%);
    background-position: 0 -15px;

    // transition is only when going to hover, otherwise the background
    // behind the gradient (there for IE<=9 fallback) gets mismatched
    .transition(background-position .1s linear);
  }

  // Focus state for keyboard and accessibility
  &:focus {
    .tab-focus();
  }

  // Active state
  &.active,
  &:active {
    background-image: none;
    @shadow: inset 0 2px 4px rgba(0,0,0,.15), 0 1px 2px rgba(0,0,0,.05);
    .box-shadow(@shadow);
    background-color: darken(@white, 10%);
    background-color: darken(@white, 15%) e("\9");
    outline: 0;
  }

  // Disabled state
  &.disabled,
  &[disabled] {
    cursor: default;
    background-image: none;
    background-color: darken(@white, 10%);
    .opacity(65);
    .box-shadow(none);
  }
}


// Button Sizes
// --------------------------------------------------

// Large
.btn-large {
  padding: 9px 14px;
  font-size: @baseFontSize + 2px;
  line-height: normal;
  .border-radius(5px);
}
.btn-large [class^="icon-"] {
  margin-top: 1px;
}

// Small
.btn-small {
  padding: 5px 9px;
  font-size: @baseFontSize - 2px;
  line-height: @baseLineHeight - 2px;
}
.btn-small [class^="icon-"] {
  margin-top: -1px;
}

// Mini
.btn-mini {
  padding: 2px 6px;
  font-size: @baseFontSize - 2px;
  line-height: @baseLineHeight - 4px;
}


// Alternate buttons
// --------------------------------------------------

// Set text color
// -------------------------
.btn-primary,
.btn-warning,
.btn-danger,
.btn-success,
.btn-info,
.btn-inverse, {
  text-shadow: 0 -1px 0 rgba(0,0,0,.25);
  color: @white;
  &:hover {
    text-shadow: 0 -1px 0 rgba(0,0,0,.25);
    color: @white;
  }
  
  // Provide *some* extra contrast for those who can get it
  &:active {
    color: rgba(255,255,255,.75);
  }
}

// Set the backgrounds
// -------------------------
.btn-primary {
  .buttonBackground(@btnPrimaryBackground, @btnPrimaryBackgroundHighlight);
}
// Warning appears are orange
.btn-warning {
  .buttonBackground(@btnWarningBackground, @btnWarningBackgroundHighlight);
}
// Danger and error appear as red
.btn-danger {
  .buttonBackground(@btnDangerBackground, @btnDangerBackgroundHighlight);
}
// Success appears as green
.btn-success {
  .buttonBackground(@btnSuccessBackground, @btnSuccessBackgroundHighlight);
}
// Info appears as a neutral blue
.btn-info {
  .buttonBackground(@btnInfoBackground, @btnInfoBackgroundHighlight);
}
// Inverse appears as dark gray
.btn-inverse {
  .buttonBackground(@btnInverseBackground, @btnInverseBackgroundHighlight);
}


// Cross-browser Jank
// --------------------------------------------------

button.btn,
input[type="submit"].btn {

  // Firefox 3.6 only I believe
  &::-moz-focus-inner {
    padding: 0;
    border: 0;
  }

  // IE7 has some default padding on button controls
  *padding-top: 2px;
  *padding-bottom: 2px;
  &.btn-large {
    *padding-top: 7px;
    *padding-bottom: 7px;
  }
  &.btn-small {
    *padding-top: 3px;
    *padding-bottom: 3px;
  }
  &.btn-mini {
    *padding-top: 1px;
    *padding-bottom: 1px;
  }
}