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

body {
  font-family: Arial, sans-serif;
  background: #eee;
  color: rgb(17, 132, 240); /* important! */
}

header {
  background: rgba(17, 132, 240, 0.3); /* nice transparent header overlay */
  padding: 20px;
  text-align: center;
}

nav a {
  color: #1184F0;
  margin: 0 10px;
  text-decoration: none;
}

nav a:hover {
  color: #eee;
}

section {
  padding: 40px;
  margin: 20px;
  border-radius: 8px;
  background: rgba(17, 132, 240, 0.2); /* light transparent card effect */
}