body {
  margin: 0;
  padding: 0;
  font-family: Arial, sans-serif;
}

#header {
  background-color: #333;
  color: #fff;
  padding: 20px;
  border-bottom: 2px solid #000;
}

#header h1 {
  margin: 0;
}

#nav {
  background-color: #000;
  overflow: hidden;
  border-bottom: 2px solid #000;
}

#nav ul {
  list-style-type: none;
  margin: 0;
  padding: 0;
}

#nav li {
  float: left;
}

#nav a {
  display: block;
  color: #fff;
  text-align: center;
  padding: 14px 16px;
  text-decoration: none;
}

#nav a:hover {
  background-color: #444;
}

#content {
  margin: 20px;
  display: flex;
  justify-content: space-between;
  text-align: center;
}

#main {
  width: 70%;
  background-color: aliceblue;
}

#side {
  width: 30%;
}

#footer {
  background-color: #333;
  color: #fff;
  text-align: center;
  padding: 10px;
  border-top: 2px solid #000;
}