title: How '+' and '&' works in CSS pseudo?
body: <p>I have following code</p>
  
  <pre><code>.check-tag__input:focus + &amp; {
          outline: none;
          background-color: #bbb;
      }
  
      .check-tag__input:checked + &amp; {
          background-color: #BADA55;
          color: #fff;
      }
  </code></pre>
  
  <p>What use of + and &amp; in this?</p>