body{
  padding: 0 20px;
  font-size: 20px;
}
div {
  display: flex;
  align-items: flex-start;
}

h1 {
  margin: 0;
}

header {
  width: 100%;
  text-align: center;
  background: #1ABC9C;
}

main {
  width: 65%;
  padding: 0 5%;
  background: #95A5A6;
}

aside {
  width: 15%;
  background: #34495E;
  padding: 0 5%;
  text-align: center;
  position: sticky;
  top: 0;  
}

ul {
  list-style: none;
  padding: 0;
}

li {
  height: 60px;
}

footer {
  width: 100%;
  height: 300px;
  background: #555;
  position: relative;
  bottom: 0;
}