html, body {
  margin: 0;
  padding: 0;
  width: 100%;
  height: 100%;
}

body {
  background-color: #e3e3e3;
}

nav {
  display: block;
  position: fixed;
  top: 0;
  left: 0;
  margin: 0;
  padding: 0;
  height: 100%;
  z-index: 999;
  
  background-color: #ea4444;
}

nav ul {
  margin: 0;
  padding: 0;
}

nav ul span {
  display: block;
  position: absolute;
  
  background-color: #fff;
}

nav ul li {
  display: block;
  list-style: none;
}

nav ul li a {
  display: block;
  padding: 20px 60px;
  
  color: #fff;
  font-family: sans-serif;
  font-size: 1.1em;
  text-decoration: none;
}

#container {
  display: block;
  position: absolute;
  top: 0;
  left: 10%;
  right: 0;
  bottom: 0;
  margin: auto;
  padding: 10px;
  width: 300px;
  height: 300px;
  
  color: #171717;
  font-family: sans-serif;
  text-align: center;
  
  background-color: #efefef;
  border-radius: 50%;
  box-shadow: 0px 0px 10px rgba(0,0,0,0.5);
}

#container:after {
  content: "";
  display: block;
  position: absolute;
  top: -15px;
  left: -15px;
  width: 350px;
  height: 350px;
  z-index: -1;
  
  background-color: #ea4444;
  border-radius: 50%;
  box-shadow: inset 0px 0px 10px rgba(0,0,0,0.5);
}

#container h1 {
  display: inline-block;
  margin: 0;
  margin-top: -20px;
  padding: 0;
  padding-top: 50%;
  
  color: #ea4444;
  font-size: 1.5em;
}