HTML

iframe to fit screen in flutter

body, html {width: 100%; height: 100%; margin: 0; padding: 0}
.row-container {display: flex; width: 100%; height: 100%; flex-direction: column; background-color: blue; overflow: hidden;}
.first-row {background-color: lime; }
.second-row { flex-grow: 1; border: none; margin: 0; padding: 0; }

iframe to fit screen in flutter

<div class="row-container">
  <div class="first-row">
    <p>Some text</p>
    <p>And some more text</p>
  </div>
  <iframe src="https://jsfiddle.net/about" class="second-row"></iframe>
</div>
 Run code snippet