<!-- File: styles.css -->
body {
  font-family: 'Roboto', sans-serif;
  font-size: 15px;
  color: #333;
  line-height: 1.6;
  margin: 0;
  padding: 0;
}

header {
  background: #fafafa;
  padding: 1.5rem;
  text-align: center;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
header h1 {
  margin: 0;
  font-size: 2rem;
  font-weight: 700;
}
header p {
  margin-top: 0.5rem;
  font-size: 1rem;
  color: #555;
}

nav {
  background: #2c3e50;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
nav ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
}
nav a {
  display: block;
  padding: 0.75rem 1.25rem;
  color: #ecf0f1;
  text-decoration: none;
  font-weight: 500;
  transition: background 0.3s;
}
nav a.active,
nav a:hover {
  background: #34495e;
  border-radius: 4px;
}

section {
  max-width: 900px;
  margin: 1.5rem auto;
  padding: 0 1rem;
}
section h2 {
  font-size: 1.5rem;
  margin-bottom: 0.75rem;
  border-bottom: 1px solid #ddd;
  padding-bottom: 0.25rem;
  font-weight: 500;
}

ul, ol {
  margin-left: 1.5rem;
}
li {
  margin-bottom: 0.5rem;
}

footer {
  background: #fafafa;
  text-align: center;
  padding: 0.75rem;
  font-size: 0.75rem;
  color: #777;
  box-shadow: 0 -2px 4px rgba(0,0,0,0.05);
}

@media (max-width: 600px) {
  nav ul {
    flex-direction: column;
  }
  header h1 {
    font-size: 1.75rem;
  }
  section h2 {
    font-size: 1.25rem;
  }
}