What is a Mixin? 2/9 won't work


The instructions were to write the @mixin backface-visibility in main.scss and then @include backface-visibility into .front, .back.
The error message "Did you assign backface visibility to .front in main.scss?" keeps popping up, even though I followed all the instructions correctly.
What did I do wrong?

@mixin backface-visibility {
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  -moz-backface-visibility: hidden;
  -ms-backface-visibility: hidden;
  -o-backface-visibility: hidden;

@mixin stripes($direction, $width-percent, $stripe-color, $stripe-background: #FFF) {
  background: repeating-linear-gradient(
    $stripe-background ($width-percent - 1),
    $stripe-color 1%,
    $stripe-background $width-percent

@mixin transform($transformation) {
  transform: $transformation;
  -webkit-transform: $transformation;
  -moz-transform: $transformation;
  -ms-transform: $transformation;
  -o-transform: $transformation;  

@mixin photo-content {
  object-fit: cover;

.notecard {
  width: 300px;
  height: 180px;
  border: 1px solid black;
  display: inline-block;
  margin: 20px;
  font-family: Roboto, sans-serif;
  box-shadow: 1px 1px 2px 2px rgba(0,0,0,.2);
  	@include transform (rotatey(-180deg));  
  .front, .back {
    width: 100%;
    height: 100%;
    position: absolute;
    @include backface-visibility;
  .front {
  z-index: 3;
  font-size: 20px;

    .word {
      display: block;
      text-align: center;
      position: relative;
      top: 40%;
  .back {
  z-index: 1;
  word-wrap: break-word;
  line-height: 1.6;
    .definition {
      width: 100%;
      height: 100%;
      .photo {
        width: 60%;
        margin: 0px auto;


Just try the problem in a different browser everything looks fine so it's probably just a bug. Scroll through the forums and you'll see it's a recurring problem


A site that teaches about web development but doesn't work in major browsers. Priceless.

Using Safari - Version 9.1.3 (9537.86.7.8) doesn't work
Using Firefox - 47.0.1 does


Its not working for me! and i opened a new browser and it wont work! heres the browser i use:
Microsoft Edge doesn't work
Google Chrome doesn't work


This topic was automatically closed 7 days after the last reply. New replies are no longer allowed.