Check if div-container has more than one div-inner no jQuery

I need a if else function that checks if div_container has more than one div_inner inside of it with Javascript only.

Here's my example code:

var inner = document.querySelector('.inner')
var container = document.querySelector('.container').innerHTML;
if(container > '1') {
  container.classList.add('test');
}
else {
  // do nothing
}
.test {
  color: red;
}
<div class="container">
  <div class="inner">Test</div>
</div>
<div class=“container”>

<div class=“inner”>Test</div>

<div class=“inner”>Test</div>

</div>

I only want to use Javascript. No jQuery at all.

#jquery #javascript