<h1>Popup Please</h1>

<a href="#popup1" class="btn">Reveal Popup</a>
<div id="popup1" class="popup">
  <a href="#" class="close">&times;</a>
  <h2>The Popup Has Arrived</h2>
  <p>This popup can be closed by clicking the fancy <b>×</b> in the top right corner or by clicking outside the popup box!</p>
</div>
<a href="#" class="close-popup"></a>

*,
*:before,
*:after {
  box-sizing: border-box;
}

html, body {
  padding: 0;
  margin: 0;
  width: 100%;
  height: 100%;
}
body {
  text-align: center;

  background-image: linear-gradient(120deg, #a6c0fe 0%, #f68084 100%);
  background-size: cover;
  background-repeat: no-repeat;
}
h1,h2,a,p {
  font-family: helvetica, sans-serif;
}
h1 {
  font-size: 3em;
  text-align: center;
  color: #00898E;
  margin: 0;
  padding: 30vh 0 1em;
}
h2 {
  text-align: center;
  white-space: nowrap;
  color: #00898E;
}
a {
  text-decoration: none;
  color: #fff;
}
p {
  text-align: left;
}
.btn {
  display: inline-block;
  padding: 10px 20px;
  border: 2px solid #00898E;
  border-radius: 10px;
  transition: background .3s;
}
.btn:hover {
  background: #00898E;
}
.popup {
  position: fixed;
  padding: 10px;
  max-width: 500px;
  border-radius: 10px;
  top: 50%;
  left: 50%;
  transform: translate(-50%,-50%);
  background: rgba(255,255,255,.9);
  visibility: hidden;
  opacity: 0;
  /* "delay" the visibility transition */
  -webkit-transition: opacity .5s, visibility 0s linear .5s;
  transition: opacity .5s, visibility 0s linear .5s;
  z-index: 1;
}
.popup:target {
  visibility: visible;
  opacity: 1;
  /* cancel visibility transition delay */
  -webkit-transition-delay: 0s;
  transition-delay: 0s;
}
.popup-close {
  position: absolute;
  padding: 10px;
  max-width: 500px;
  border-radius: 10px;
  top: 50%;
  left: 50%;
  transform: translate(-50%,-50%);
  background: rgba(255,255,255,.9);
}
.popup .close {
  position: absolute;
  right: 5px;
  top: 5px;
  padding: 5px;
  color: #000;
  transition: color .3s;
  font-size: 2em;
  line-height: .6em;
  font-weight: bold;
}
.popup .close:hover {
  color: #00E5EE;
}

.close-popup {
  background: rgba(0,0,0,.7);
  cursor: default;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  opacity: 0;
  visibility: hidden;
  /* "delay" the visibility transition */
  -webkit-transition: opacity .5s, visibility 0s linear .5s;
  transition: opacity .5s, visibility 0s linear .5s;
}
.popup:target + .close-popup{  
  opacity: 1;
  visibility: visible;
  /* cancel visibility transition delay */
  -webkit-transition-delay: 0s;
  transition-delay: 0s;
}

// ¯\_(ツ)_/¯

/*
 My own version of https://codepen.io/imprakash/pen/GgNMXO
*/