<div>
    <a class="hidden" href="#">Skip to content</a>
<div>
<div id="content"> ..... </div>

body {
  margin: 0;
}

* {
 box-sizing: border-box;
}

div {
  height: 50px;
  background: #E84C3D;
}

.hidden {
  padding: 8px;
  position: absolute;
  background: #E77E23;
  left: 50%;
  height: 30px;
  transform: translateY(-100%);
  transition: transform 0.3s;
}

a:focus {
  transform: translateY(0%);
}

a {
  color: #333;
  text-decoration: none;
}