--description--

For this challenge, you'll change the opacity of an animated element so it gradually fades as it reaches the right side of the screen.

In the displayed animation, the round element with the gradient background moves to the right by the 50% mark of the animation per the @keyframes rule.

--instructions--

Target the element with the id of ball and add the opacity property set to 0.1 at 50%, so the element fades as it moves to the right.

--hints--

The keyframes rule for fade should set the opacity property to 0.1 at 50%.

assert(
  code.match(
    /@keyframes fade\s*?{\s*?50%\s*?{\s*?(?:left:\s*?60%;\s*?opacity:\s*?0?\.1;|opacity:\s*?0?\.1;\s*?left:\s*?60%;)/gi
  )
);

--seed--

--seed-contents--

<style>

  #ball {
    width: 70px;
    height: 70px;
    margin: 50px auto;
    position: fixed;
    left: 20%;
    border-radius: 50%;
    background: linear-gradient(
      35deg,
      #ccffff,
      #ffcccc
    );
    animation-name: fade;
    animation-duration: 3s;
  }

  @keyframes fade {
    50% {
      left: 60%;

    }
  }

</style>

<div id="ball"></div>

--solutions--

<style>
  #ball {
    width: 70px;
    height: 70px;
    margin: 50px auto;
    position: fixed;
    left: 20%;
    border-radius: 50%;
    background: linear-gradient(
      35deg,
      #ccffff,
      #ffcccc
    );
    animation-name: fade;
    animation-duration: 3s;
  }

  @keyframes fade {
    50% {
      left: 60%;
      opacity: 0.1;
    }
  }
</style>
<div id="ball"></div>