body {
  font-family: Arial, sans-serif;
  line-height: 1.6;
  margin: 0;
  padding: 0;
  background: #f5f5f5;
  color: #333;
}

header, footer {
  background: #2c3e50;
  color: white;
  padding: 15px;
  text-align: center;
}

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

nav ul li {
  display: inline;
  margin: 0 10px;
}

nav a {
  color: #fff;
  text-decoration: none;
}

main {
  max-width: 900px;
  margin: 20px auto;
  background: #fff;
  padding: 20px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

h1, h2 {
  color: #2c3e50;
}

img {
  border-radius: 50%;
  margin-top: 10px;
}

@media (max-width: 600px) {
  nav ul li {
    display: block;
    margin: 5px 0;
  }
}

pre {
  background: #2c3e50;
  color: #f8f8f2;
  padding: 10px;
  border-radius: 5px;
  overflow-x: auto;
}