title: CSS brightnesss filter blurs text
body: <p>Using <code>filter: brightness(x)</code> on an element leads to the text inside being blurred under Chrome and Firefox. Is this desired behavior? If not, can this be fixed? Here's a fiddle demonstrating the issue:</p>
  
  <p><a href="https://jsfiddle.net/dye2n0xv/" rel="noreferrer">https://jsfiddle.net/dye2n0xv/</a></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>button {
    border: none;
    background: linear-gradient(#53a423, #2f6c04);
    color: #fff;
    font-weight: bold;
    padding: 10px;
  }
  
  button:hover {
    filter: brightness(100%);
  }</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;button&gt;
  Some button label
  &lt;/button&gt;</code></pre>
  </div>
  </div>
  </p>
  
  <p>Just hover the mouse over the button and pay attention to the text. Of course, the example with 100% is stupid, in my use-case I need something like 125%, but I wanted to make sure it's not the browser trying to display a whiter white than white, that's why I went with 100% which should theoretically not alter the element at all.</p>