<!DOCTYPE HTML>
<html>
<head>
<style>
#grid_container {
  display: grid;
  align-items:end;
}

#inner {
  width: 100%;
  background-color: green;
}
</style>
</head>
<body>
<div id="grid_container">
  <div>
    <canvas id="inner" width="100" height="100"></img>
  </div>
</div>

<script>
  let container = document.getElementById('grid_container');
  window.getComputedStyle(container).width;
  container.style.width = '150px';
</script>
</body>
</html>
