body {
  font-family: "Segoe UI", Arial, sans-serif;
  background-color: #fafafa;
  color: #333;
  margin: 0;
  padding: 0 20px 40px;
  line-height: 1.6;
}
header, footer {
  text-align: center;
  padding: 15px;
}
header h1 {
  color: #222;
  margin-bottom: 10px;
}
nav {
  text-align: center;
  margin-bottom: 20px;
}
nav a {
  color: #0078d7;
  text-decoration: none;
  margin: 0 5px;
}
nav a:hover {
  text-decoration: underline;
}
main {
  max-width: 900px;
  margin: 0 auto;
  background: #fff;
  padding: 25px;
  border-radius: 12px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}
h2 {
  color: #222;
  margin-top: 25px;
}
footer {
  font-size: 0.9em;
  color: #777;
  margin-top: 40px;
}