title: how to let backface-visibilty works in code here?
body: <p>i have this code here ,but my problem is when the page loads the memory game images all appears (they are not hidden) and i want them to be hidden so when i click on them it flippes to show the image and i think the problem is in css code here (.deck .card .open) backface-visibility is not working also animation-name: flipInY; is not working too
  Thanks in advance</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>html {
    box-sizing: border-box;
  }
  
  html,
  body {
    width: 100%;
    height: 140%;
    margin: 0;
    padding: 0;
  }
  
  body {
    display: flex;
    flex-direction: row;
    flex-wrap: nowrap;
    justify-content: center;
    align-items: center;
  }
  
  .deck .card {
    width: 21%;
    margin: 2%;
    height: 130px;
    position: relative;
    perspective: 800px;
    background: #141214;
    ;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    box-shadow: 5px 2px 20px 0 rgba(46, 61, 73, 0.5);
  }
  
  .table {
    background: rgb(165, 181, 252);
    display: flex;
    flex-direction: row;
    flex-wrap: wrap;
    width: 200%;
    margin: 0 auto;
    border-radius: 4px;
    box-shadow: 8px 9px 26px 0 rgba(14, 133, 231, 0.5);
  }
  
  .deck {
    width: 100%;
    height: 80%;
    display: flex;
    transform-style: preserve-3d;
    transition: transform 1s;
    flex-wrap: wrap;
    align-items: center;
  }
  
  .card img {
    margin: 0;
    display: block;
    position: absolute;
    width: 60p%;
    height: 60%;
    transform-style: preserve-3d;
  }
  
  .deck .card.open {
    transform-style: preserve-3d;
    background: #02b3e4;
    cursor: default;
    animation-name: flipInY;
    -webkit-backface-visibility: visible !important;
    backface-visibility: visible !important;
    animation-duration: .75s;
  }
  
  .deck .card.show {
    font-size: 33px;
  }
  
  .deck .card.match {
    cursor: default;
    background: #E5F720;
    font-size: 33px;
    animation-name: rubberBand;
    -webkit-backface-visibility: visible !important;
    backface-visibility: visible !important;
    animation-duration: .75s;
  }
  
  .deck .card.unmatched {
    animation-name: pulse;
    -webkit-backface-visibility: visible !important;
    backface-visibility: visible !important;
    animation-duration: .75s;
    background: #e2043b;
  }
  
  .deck .card.disabled {
    pointer-events: none;
    opacity: 0.9;
  }
  
  .score-panel {
    text-align: left;
    margin-bottom: 10px;
  }
  
  .score-panel .stars {
    margin: 0;
    padding: 0;
    display: inline-block;
    margin: 0 5px 0 0;
  }
  
  .score-panel .stars li {
    list-style: none;
    display: inline-block;
  }
  
  .score-panel .restart {
    float: right;
    cursor: pointer;
  }
  
  .fa-star {
    color: #FFD700;
  }
  
  .timer {
    display: inline-block;
    margin: 0 1rem;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;section&gt;
    &lt;div class="restart" onclick=startGame()&gt;
      &lt;i class="fa fa-repeat"&gt;&lt;/i&gt;
    &lt;/div&gt;
  &lt;/section&gt;
  &lt;section class="table"&gt;
  
    &lt;ul class="deck" id="card-deck"&gt;
      &lt;li class="card" type="diamond"&gt;
        &lt;img src="img/1.png"&gt;
      &lt;/li&gt;
      &lt;li class="card" type="plane"&gt;
        &lt;img src="img/2.png"&gt;
      &lt;/li&gt;
      &lt;li class="card match" type="anchor"&gt;
        &lt;img src="img/3.png"&gt;
      &lt;/li&gt;
      &lt;li class="card" type="bolt"&gt;
        &lt;img src="img/4.png"&gt;
      &lt;/li&gt;
      &lt;li class="card" type="cube"&gt;
        &lt;img src="img/5.png"&gt;
      &lt;/li&gt;
      &lt;li class="card match" type="anchor"&gt;
        &lt;img src="img/3.png"&gt;
      &lt;/li&gt;
      &lt;li class="card" type="leaf"&gt;
        &lt;img src="img/6.png"&gt;
      &lt;/li&gt;
      &lt;li class="card" type="bicycle"&gt;
        &lt;img src="img/7.png"&gt;
      &lt;/li&gt;
      &lt;li class="card" type="diamond"&gt;
        &lt;img src="img/1.png"&gt;
      &lt;/li&gt;
      &lt;li class="card" type="bomb"&gt;
        &lt;img src="img/8.png"&gt;
      &lt;/li&gt;
      &lt;li class="card" type="leaf"&gt;
        &lt;img src="img/6.png"&gt;
      &lt;/li&gt;
      &lt;li class="card" type="bomb"&gt;
        &lt;img src="img/8.png"&gt;
      &lt;/li&gt;
      &lt;li class="card open show" type="bolt"&gt;
        &lt;img src="img/4.png"&gt;
      &lt;/li&gt;
      &lt;li class="card" type="bicycle"&gt;
        &lt;img src="img/7.png"&gt;
      &lt;/li&gt;
      &lt;li class="card" type="plane"&gt;
        &lt;img src="img/2.png"&gt;
      &lt;/li&gt;
      &lt;li class="card" type="cube"&gt;
        &lt;img src="img/5.png"&gt;
      &lt;/li&gt;
    &lt;/ul&gt;
  &lt;/section&gt;</code></pre>
  </div>
  </div>
  </p>