Collapsable Banner

A banner that collapses when a "button" is toggled

by Nate

HTML

<aside class="container">
  <input type="checkbox" id="box" />
  <label id="toggle" for="box"></label>

  <a href="" id="collapsible">
    This will collapse!
  </a>
</aside>

CSS

* {
  margin: 0;
  padding: 0;
}

.container {
  display: block;
  color: white;
  text-align: center;
  position: fixed;
  top: 20px;
  right: 20px;
  font-size: 2em;
}

#box {
  display: none;
}

#toggle, #collapsible {
  display: block;
  color: white;
  text-decoration: none;
}

#toggle {
  float: left;
  background: green;
  padding: 0 10px;
}

#collapsible {
  background: red;
  float: right;
  transition: padding 2s;
  white-space: nowrap;
  padding: 0 10px;
}

#box ~ #toggle:after {
  content: "/>";
}

#box:checked ~ #toggle:after {
  content: "<";
}

#box:checked ~ #collapsible {
  width: 0;
  padding: 0;
  overflow: hidden;
}