<div class="thing">
  <h2>a little title</h2>
  <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Cupiditate ab tenetur at delectus aspernatur similique modi, est, debitis sit voluptate dolorem eligendi odio laborum magni nesciunt? Aliquam omnis molestiae at.</p>
</div>

<h1 class="heading"> Hover Me 👆</h1>
.thing {
  padding: 1rem;
  width: 420px;
  box-shadow: 0 15px 30px 0 rgba(0,0,0,0.11),
    0 5px 15px 0 rgba(0,0,0,0.08);
  background-color: #ffffff;
  border-radius: 0.5rem;
  
  border-left: 0 solid #00ff99;
  transition: border-left 300ms ease-in-out, padding-left 300ms ease-in-out;
}

.thing:hover {
  padding-left: 0.5rem;
  border-left: 0.5rem solid #00ff99;
}

.thing > :first-child {
  margin-top: 0;
}

.thing > :last-child {
  margin-bottom: 0;
}

.heading {
  color: #fff;
}

body {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  width: 100vw;
  height: 100vh;
  background-color: #0099ff;
}

External CSS

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External JavaScript

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