SassFlexbox comes with a bunch of placeholders and mixins to help you use Flexbox without worrying about vendor prefixes. Whenever possible, extend placeholders are provided to allow you to not create so much duplicated code.

// --------------------------------------------------
// Flexbox SASS mixins
// The spec: http://www.w3.org/TR/css3-flexbox
// --------------------------------------------------

// Flexbox display
@mixin flexbox() {
  display: -webkit-box;
  display: -moz-box;
  display: -ms-flexbox;
  display: -webkit-flex;
  display: flex;
}

// The 'flex' shorthand
// - applies to: flex items
// , initial, auto, or none
@mixin flex($values) {
  -webkit-box-flex: $values;
     -moz-box-flex: $values;
      -webkit-flex: $values;
  	  -ms-flex: $values;
  	      flex: $values;
}

// Flex Flow Direction
// - applies to: flex containers
// row | row-reverse | column | column-reverse
@mixin flex-direction($direction) {
  -webkit-flex-direction: $direction;
     -moz-flex-direction: $direction;
      -ms-flex-direction: $direction;
          flex-direction: $direction;
}

// Flex Line Wrapping
// - applies to: flex containers
// nowrap | wrap | wrap-reverse
@mixin flex-wrap($wrap) {
  -webkit-flex-wrap: $wrap;
     -moz-flex-wrap: $wrap;
      -ms-flex-wrap: $wrap;
          flex-wrap: $wrap;
}

// Flex Direction and Wrap
// - applies to: flex containers
//  || 
@mixin flex-flow($flow) {
  -webkit-flex-flow: $flow;
     -moz-flex-flow: $flow;
      -ms-flex-flow: $flow;
          flex-flow: $flow;
}

// Display Order
// - applies to: flex items
// 
@mixin order($val) {
  -webkit-box-ordinal-group: $val;  
     -moz-box-ordinal-group: $val;     
  	     -ms-flex-order: $val;     
  	      -webkit-order: $val;  
  		      order: $val;
}

// Flex grow factor
// - applies to: flex items
// 
@mixin flex-grow($grow) {
  -webkit-flex-grow: $grow;
     -moz-flex-grow: $grow;
      -ms-flex-grow: $grow;
          flex-grow: $grow;
}

// Flex shrink
// - applies to: flex item shrink factor
//  
@mixin flex-shrink($shrink) {
  -webkit-flex-shrink: $shrink;
     -moz-flex-shrink: $shrink;
      -ms-flex-shrink: $shrink;
          flex-shrink: $shrink;
}

// Flex basis
// - the initial main size of the flex item
// - applies to: flex itemsnitial main size of the flex item
//  
@mixin flex-basis($width) {
  -webkit-flex-basis: $width;
     -moz-flex-basis: $width;
      -ms-flex-basis: $width;
          flex-basis: $width;
}

// Axis Alignment
// - applies to: flex containers
// flex-start | flex-end | center | space-between | space-around 
@mixin justify-content($justify) {
  -webkit-justify-content: $justify;
     -moz-justify-content: $justify;
      -ms-justify-content: $justify;
          justify-content: $justify;
            -ms-flex-pack: $justify;
}

// Packing Flex Lines
// - applies to: multi-line flex containers
// flex-start | flex-end | center | space-between | space-around | stretch 
@mixin align-content($align) {
  -webkit-align-content: $align;
     -moz-align-content: $align;
      -ms-align-content: $align;
          align-content: $align;
}

// Cross-axis Alignment
// - applies to: flex containers
// flex-start | flex-end | center | baseline | stretch 
@mixin align-items($align) {
  -webkit-align-items: $align;
     -moz-align-items: $align;
      -ms-align-items: $align;
          align-items: $align;
}

// Cross-axis Alignment
// - applies to: flex items
// auto | flex-start | flex-end | center | baseline | stretch 
@mixin align-self($align) {
  -webkit-align-self: $align;
     -moz-align-self: $align;
      -ms-align-self: $align;
          align-self: $align;
}