title: WKWebView page height issue on iPhone X
body: <p>I find that if I use WKWebView with </p>
  
  <pre><code>viewport-fit=cover
  </code></pre>
  
  <p>and </p>
  
  <pre><code>body :{height:100%}
  </code></pre>
  
  <p>the height of html body still can not reach the bottom of iPhone X and is equal to the height of safeArea, However, the background-color can cover the fullscreen.</p>
  
  <p><a href="https://ue.qzone.qq.com/touch/proj-qzone-app/test.html" rel="noreferrer">https://ue.qzone.qq.com/touch/proj-qzone-app/test.html</a></p>
  
  <p>I load this page in a fullscreen WKWebView to reproduce the problem.</p>