<h4>Scroll to see the sticky element <em>sticking</em></h4>
<div class="extra"></div>
<br />
<div id="wrapper">
  <div id="sticky">
    sticky
  </div>
</div>
<br />
<div class="extra"></div>

#sticky {
  position: sticky;
  position: -webkit-sticky;
  background: #f83d23;
  width: 100px;
  height: 100px;
  top: 70px;
  display: flex;
  justify-content: center;
  align-items: center;
  box-shadow: 0 0 6px #000;
  color: #fff;
}
.extra,
#wrapper {
  width: 75%;
  margin: auto;
  background-color: #ccc;
}
#wrapper {
  height: 800px;
}
.extra {
  height: 100px;
}
body {
  font-family: georgia;
  height: 1000px;
}
h4 {
  text-align: center;
}
@media (min-height: 768px) {
  #wrapper{
    height: 2000px;
  }
}