title: Prevent double border from responsive columns
body: <p>Imagine you are using Bootstrap 4 and printing some cells. Cell numbers are unpredictable.</p>
  
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-css lang-css prettyprint-override"><code>.cell {
    border: 1px solid black;
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;link href="https://stackpath.bootstrapcdn.com/bootstrap/4.3.1/css/bootstrap.min.css" rel="stylesheet"&gt;
  
  &lt;div class="row no-gutters"&gt;
    &lt;div class="cell col-6 col-sm-4 col-md-3 col-lg-2"&gt;cell&lt;/div&gt;
    &lt;div class="cell col-6 col-sm-4 col-md-3 col-lg-2"&gt;cell&lt;/div&gt;
    &lt;div class="cell col-6 col-sm-4 col-md-3 col-lg-2"&gt;cell&lt;/div&gt;
    &lt;div class="cell col-6 col-sm-4 col-md-3 col-lg-2"&gt;cell&lt;/div&gt;
    &lt;div class="cell col-6 col-sm-4 col-md-3 col-lg-2"&gt;cell&lt;/div&gt;
    &lt;div class="cell col-6 col-sm-4 col-md-3 col-lg-2"&gt;cell&lt;/div&gt;
    &lt;div class="cell col-6 col-sm-4 col-md-3 col-lg-2"&gt;cell&lt;/div&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>When you run code, you see "double" borders. If I use nth-child selector, <strong>I have to calculate every breakpoint</strong>, because on specific breakpoint it shows different cells per row. How you solve it?</p>