title: What is the cause of this change in label style immediately after touching, in iOS 13.3.1?
body: <p>The following code presents three options as labels for a radio button group.</p>
  
  <p>When clicking a label, the <code>background-color</code> should transition.</p>
  
  <p>It works as expected in Chrome and Safari 13.0.4 on OSX 10.15.2, but in iOS 13.3.1 a style (the label darkens) is briefly applied to the label immediately after touching.</p>
  
  <p>Why might this be? Perhaps a touch-related pseudo class is being activated briefly and the browser stylesheet is causing the appearance of flicker.</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>input[type="radio"] {
    display: none;
  }
  
  label {
    font-family: sans-serif;
    padding: 10px;
    margin: 10px;
    display: block;
    cursor: pointer;
    border-radius: 5px;
  }
  
  input[type="radio"]+label {
    background-color: rgba(0,220,220,0);
    transition: background-color 1.5s ease-in 0s;
  }
  
  input[type="radio"]:checked+label {
    background-color: rgba(0,220,220,1);
  }
  
  #time {
    width: 100%;
    font-family: sans-serif;
    font-size: 2em;
    text-align: center;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;input type="radio" name="group1" id="london" checked&gt;
  &lt;label for="london"&gt;London&lt;/label&gt;
  &lt;input type="radio" name="group1" id="amsterdam"&gt;
  &lt;label for="amsterdam"&gt;Amsterdam&lt;/label&gt;
  &lt;input type="radio" name="group1" id="new-york"&gt;
  &lt;label for="new-york"&gt;New York&lt;/label&gt;
  &lt;div id="time"&gt;&lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>