JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://getfirebug.com/firebug-lite-debug.js"></script>
<div class="outer">
  <div class="select">
    <div class="inner"></div>
      </div>
       <div class="inner"></div>
</div>

JavaScript

var select = document.querySelector('.select');
var inner = select.querySelectorAll('.outer .inner');
console.log(inner.length); // 1, not 0!

var inner1 = select.querySelectorAll(':scope .inner');
console.log(inner1.length); // 1, not 0!