body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  margin: 0;
  background-color: #0f0f0f;
  color: #f1f1f1;
  line-height: 1.7;
}
header, footer {
  background-color: #1a1a1a;
  padding: 1.2em 2em;
  text-align: center;
}
header h1 {
  margin: 0;
  font-size: 2em;
  color: #00ffc3;
}
nav {
  margin-top: 0.5em;
}
nav a {
  color: #ccc;
  margin: 0 1em;
  text-decoration: none;
  font-weight: 600;
}
nav a:hover {
  color: #00ffc3;
}
.container {
  padding: 2em;
  max-width: 960px;
  margin: auto;
}
footer {
  margin-top: 3em;
  font-size: 0.9em;
  color: #aaa;
}