html,
body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  margin: 0;
  background: #eee;
}
h1 {
  position: absolute;
  left: 20px;
  font-family: sans-serif;
}
.circle {
  width: 40px;
  height: 40px;
  background: blue;
  position: absolute;
  border-radius: 50%;
  opacity: 0.4;
}