title: getBoundingClientRect().width not returning correct width
body: <p>I am trying to get the width of an element, but the value is always less than the actual width. This is my code so far:</p>
  
  <pre><code>this.rightSectionElement = this.$('.sections').eq(1).get(0);
  this.rightSectionOffset = this.rightSectionElement.getBoundingClientRect().width;
  </code></pre>
  
  <p>Where the CSS on the element in question is this:</p>
  
  <pre><code>nav{
      position: relative;
      width: 100%;
      height: 100%;
      @include inline-flex();
      flex-wrap: nowrap;
      justify-content: space-between;
      z-index: 1;
  
      .sections{
                @include flex-value(0 1 auto);
                height: 100%;
                width: auto;
                display: block;
  ...
  </code></pre>
  
  <p>Does this method not play very well with elements arranged by flexbox?</p>