title: how to make ANY hovered color darker/lighter that the original
body: <p>i want to make it so that when you hover over an element, it's always darker or lighter than it initially was. regardless of the color</p>
  
  <p>something like this but universal</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>.darker{
  Background:red;
  width:100px;
  height:100px
  }
  
  .darker:hover{
  Background:#b20000
  }
  .lighter {
  Background:blue;
  width:100px;
  height:100px
  }
  
  .lighter:hover{
  Background:#adccff
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;div class='darker'&gt;&lt;/div&gt;
  &lt;div class='lighter'&gt;&lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>