title: what is the usage of -webkit-fill-available?
body: <p>PIC-1</p>
  <p>this is what I've ( pic-1 )</p>
  <p><a href="https://i.stack.imgur.com/u5dFD.png" rel="noreferrer"><img src="https://i.stack.imgur.com/u5dFD.png" alt="this is what I've ( pic-1 )" /></a></p>
  <p>PIC-2</p>
  <p>this is what I need ( pic-2 )</p>
  <p><a href="https://i.stack.imgur.com/kPqcl.png" rel="noreferrer"><img src="https://i.stack.imgur.com/kPqcl.png" alt="this is what I need ( pic-2 )" /></a></p>
  <p>in the pic-2 I added</p>
  <pre><code>width: -webkit-fill-available;
  </code></pre>
  <p>I got what I expect. But I don't know how it's working.</p>