 width: 10rem;
      height: 5rem;
      margin: auto;
      border: none;
      flex-grow: 0;
      flex-shrink: 0;
      box-shadow: inset 0 0 0 2px rgba(255, 255, 255, .2);
    }
  </style>
</head>
<body>
  <div id="test-wrapper">
    <section class="demo normal">
      <h1>Normal</h1>
      <div class="demo-line">
        <span></span><span></span><span></span><span></span><span></span><span></span><span></span><span></span><span></span><span></span><span></span>
      </div>
    </section>

    <sectio