Не работает всплывающее меню, толи дело в скрипте, ибо кнопки не открываются, то ли в css что-то не так

  jQuery(function($) {
  var zindex = 10;
  
  $("div.card").click(function(e){

    var isShowing = false;
    
    if ($(this).hasClass("show")) {
      isShowing = true
    }

    if ($("div.cards").hasClass("showing")) {
      // a card is already in view
      $("div.card.show")
        .removeClass("show");

      if (isShowing) {
        // this card was showing - reset the grid
        $("div.cards")
          .removeClass("showing");
      } else {
        // this card isn't showing - get in with it
        $(this)
          .css({zIndex: zindex})
          .addClass("show");

      }

      zindex++;

    } else {
      // no cards in view
      $("div.cards")
        .addClass("showing");
      $(this)
        .css({zIndex:zindex})
        .addClass("show");

      zindex++;
    }
    
  });
  });

@import url(https://fonts.googleapis.com/css?family=Source+Sans+Pro:400,200,300,600,700,900);
body {
background: #dce1df;
color: #4f585e;
font-family: 'Source Sans Pro', sans-serif;
text-rendering: optimizeLegibility;
}
a.btn {
background: #0096a0;
border-radius: 4px;
box-shadow: 0 2px 0px 0 rgba(0,0,0,0.25);
color: #ffffff;
display: inline-block;
padding: 6px 30px 8px;
position: relative;
text-decoration: none;
transition: all 0.1s 0s ease-out;
}
.no-touch a.btn:hover {
background: #00a2ad;
box-shadow: 0px 8px 2px 0 rgba(0,0,0,0.075);
transform: translateY(-2px);
transition: all 0.25s 0s ease-out;
}
.no-touch a.btn:active, a.btn:active {
background: #008a93;
box-shadow: 0 1px 0px 0 rgba(255,255,255,0.25);
transform: translate3d(0,1px,0);
transition: all 0.025s 0s ease-out;
}
div.cards {
margin: 80px auto;
max-width: 960px;
text-align: center;
}
div.card {
background: #ffffff;
display: inline-block;
margin: 8px;
max-width: 300px;
perspective: 1000;
position: relative;
text-align: left;
transition: all 0.3s 0s ease-in;
z-index: 1;
}
div.card img {
max-width: 300px;
}
div.card div.card-title {
background: #ffffff;
padding: 6px 15px 10px;
position: relative;
z-index: 0;
}
div.card div.card-title a.toggle-info {
border-radius: 32px;
height: 32px;
padding: 0;
position: absolute;
right: 15px;
top: 10px;
width: 32px;
}
div.card div.card-title a.toggle-info span {
background: #ffffff;
display: block;
height: 2px;
position: absolute;
top: 16px;
transition: all 0.15s 0s ease-out;
width: 12px;
}
div.card div.card-title a.toggle-info span.left {
right: 14px;
transform: rotate(45deg);
}
div.card div.card-title a.toggle-info span.right {
left: 14px;
transform: rotate(-45deg);
}
div.card div.card-title h2 {
font-size: 24px;
font-weight: 700;
letter-spacing: -0.05em;
margin: 0;
padding: 0;
}
div.card div.card-title h2 small {
display: block;
font-size: 18px;
font-weight: 600;
letter-spacing: -0.025em;
}
div.card div.card-description {
padding: 0 15px 10px;
position: relative;
font-size: 14px;
}
div.card div.card-actions {
box-shadow: 0 2px 0px 0 rgba(0,0,0,0.075);
padding: 10px 15px 20px;
text-align: center;
}
div.card div.card-flap {
background: #d9d9d9;
position: absolute;
width: 100%;
transform-origin: top;
transform: rotateX(-90deg);
}
div.card div.flap1 {
transition: all 0.3s 0.3s ease-out;
z-index: -1;
}
div.card div.flap2 {
transition: all 0.3s 0s ease-out;
z-index: -2;
}
div.cards.showing div.card {
cursor: pointer;
opacity: 0.6;
transform: scale(0.88);
}
.no-touch div.cards.showing div.card:hover {
opacity: 0.94;
transform: scale(0.92);
}
div.card.show {
opacity: 1 !important;
transform: scale(1) !important;
}
div.card.show div.card-title a.toggle-info {
background: #ff6666 !important;
}
div.card.show div.card-title a.toggle-info span {
top: 15px;
}
div.card.show div.card-title a.toggle-info span.left {
right: 10px;
}
div.card.show div.card-title a.toggle-info span.right {
left: 10px;
}
div.card.show div.card-flap {
background: #ffffff;
transform: rotateX(0deg);
}
div.card.show div.flap1 {
transition: all 0.3s 0s ease-out;
}
div.card.show div.flap2 {
transition: all 0.3s 0.2s ease-out;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    
    
    <link rel="stylesheet" href="../assets/css/price.css">
    <!-- <link rel="stylesheet" href="https://cdn.jsdelivr.net/npm/bootstrap@5.2.3/dist/css/bootstrap.min.css"> -->
    <title>Molekula</title>
</head>
<body>
<!-- header -->
    <header>
        
    </header> 
    <!-- main -->
    <main>
      <div class="cards">

        <div class="card">
          <div class="card__image-holder">
            <img class="card__image" src="https://source.unsplash.com/300x225/?wave" alt="wave" />
          </div>
          <div class="card-title">
            <a href="#" class="toggle-info btn">
              <span class="left"></span>
              <span class="right"></span>
            </a>
            <h2>
                Card title
                <small>Image from unsplash.com</small>
            </h2>
          </div>
          <div class="card-flap flap1">
            <div class="card-description">
              This grid is an attempt to make something nice that works on touch devices. Ignoring hover states when they're not available etc.
            </div>
            <div class="card-flap flap2">
              <div class="card-actions">
                <a href="#" class="btn">Read more</a>
              </div>
            </div>
          </div>
        </div>
      
        <div class="card">
          <div class="card__image-holder">
            <img class="card__image" src="https://source.unsplash.com/300x225/?beach" alt="beach" />
          </div>
          <div class="card-title">
            <a href="#" class="toggle-info btn">
              <span class="left"></span>
              <span class="right"></span>
            </a>
            <h2>
                Card title
                <small>Image from unsplash.com</small>
            </h2>
          </div>
          <div class="card-flap flap1">
            <div class="card-description">
              This grid is an attempt to make something nice that works on touch devices. Ignoring hover states when they're not available etc.
            </div>
            <div class="card-flap flap2">
              <div class="card-actions">
                <a href="#" class="btn">Read more</a>
              </div>
            </div>
          </div>
        </div>
      
        <div class="card">
          <div class="card__image-holder">
            <img class="card__image" src="https://source.unsplash.com/300x225/?mountain" alt="mountain" />
          </div>
          <div class="card-title">
            <a href="#" class="toggle-info btn">
              <span class="left"></span>
              <span class="right"></span>
            </a>
            <h2>
                Card title
                <small>Image from unsplash.com</small>
            </h2>
          </div>
          <div class="card-flap flap1">
            <div class="card-description">
              This grid is an attempt to make something nice that works on touch devices. Ignoring hover states when they're not available etc.
            </div>
            <div class="card-flap flap2">
              <div class="card-actions">
                <a href="#" class="btn">Read more</a>
              </div>
            </div>
          </div>
        </div>
      
        <div class="card">
          <div class="card__image-holder">
            <img class="card__image" src="https://source.unsplash.com/300x225/?field" alt="field" />
          </div>
          <div class="card-title">
            <a href="#" class="toggle-info btn">
              <span class="left"></span>
              <span class="right"></span>
            </a>
            <h2>
                Card title
                <small>Image from unsplash.com</small>
            </h2>
          </div>
          <div class="card-flap flap1">
            <div class="card-description">
              This grid is an attempt to make something nice that works on touch devices. Ignoring hover states when they're not available etc.
            </div>
            <div class="card-flap flap2">
              <div class="card-actions">
                <a href="#" class="btn">Read more</a>
              </div>
            </div>
          </div>
        </div>
      
        <div class="card">
          <div class="card__image-holder">
            <img class="card__image" src="https://source.unsplash.com/300x225/?water" alt="water" />
          </div>
          <div class="card-title">
            <a href="#" class="toggle-info btn">
              <span class="left"></span>
              <span class="right"></span>
            </a>
            <h2>
                Card title
                <small>Image from unsplash.com</small>
            </h2>
          </div>
          <div class="card-flap flap1">
            <div class="card-description">
              This grid is an attempt to make something nice that works on touch devices. Ignoring hover states when they're not available etc.
            </div>
            <div class="card-flap flap2">
              <div class="card-actions">
                <a href="#" class="btn">Read more</a>
              </div>
            </div>
          </div>
        </div>
      
        <div class="card">
          <div class="card__image-holder">
            <img class="card__image" src="https://source.unsplash.com/300x225/?river" alt="river" />
          </div>
          <div class="card-title">
            <a href="#" class="toggle-info btn">
              <span class="left"></span>
              <span class="right"></span>
            </a>
            <h2>
                Card title
                <small>Image from unsplash.com</small>
            </h2>
          </div>
          <div class="card-flap flap1">
            <div class="card-description">
              This grid is an attempt to make something nice that works on touch devices. Ignoring hover states when they're not available etc.
            </div>
            <div class="card-flap flap2">
              <div class="card-actions">
                <a href="#" class="btn">Read more</a>
              </div>
            </div>
          </div>
        </div>
      
        <div class="card">
          <div class="card__image-holder">
            <img class="card__image" src="https://source.unsplash.com/300x225/?kite" alt="kite" />
          </div>
          <div class="card-title">
            <a href="#" class="toggle-info btn">
              <span class="left"></span>
              <span class="right"></span>
            </a>
            <h2>
                Card title
                <small>Image from unsplash.com</small>
            </h2>
          </div>
          <div class="card-flap flap1">
            <div class="card-description">
              This grid is an attempt to make something nice that works on touch devices. Ignoring hover states when they're not available etc.
            </div>
            <div class="card-flap flap2">
              <div class="card-actions">
                <a href="#" class="btn">Read more</a>
              </div>
            </div>
          </div>
        </div>
        
        <div class="card">
          <div class="card__image-holder">
            <img class="card__image" src="https://source.unsplash.com/300x225/?underwater" alt="underwater" />
          </div>
          <div class="card-title">
            <a href="#" class="toggle-info btn">
              <span class="left"></span>
              <span class="right"></span>
            </a>
            <h2>
                Card title
                <small>Image from unsplash.com</small>
            </h2>
          </div>
          <div class="card-flap flap1">
            <div class="card-description">
              This grid is an attempt to make something nice that works on touch devices. Ignoring hover states when they're not available etc.
            </div>
            <div class="card-flap flap2">
              <div class="card-actions">
                <a href="#" class="btn">Read more</a>
              </div>
            </div>
          </div>
        </div>
      
        <div class="card">
          <div class="card__image-holder">
            <img class="card__image" src="https://source.unsplash.com/300x225/?desert" alt="desert" />
          </div>
          <div class="card-title">
            <a href="#" class="toggle-info btn">
              <span class="left"></span>
              <span class="right"></span>
            </a>
            <h2>
                Card title
                <small>Image from unsplash.com</small>
            </h2>
          </div>
          <div class="card-flap flap1">
            <div class="card-description">
              This grid is an attempt to make something nice that works on touch devices. Ignoring hover states when they're not available etc.
            </div>
            <div class="card-flap flap2">
              <div class="card-actions">
                <a href="#" class="btn">Read more</a>
              </div>
            </div>
          </div>
        </div>
      
      </div>
      
    </main>
    <footer>
        
    </footer>
    <script src="../assets/js/price.js"></script>
</body>
</html>