body {
  margin: 0;
  font-family: 'Inter', sans-serif;
  background-color: #f9f9f9;
  color: #333;
  line-height: 1.6;
}

.container {
  width: 90%;
  max-width: 800px;
  margin: 0 auto;
  padding: 20px;
}

header {
  background: #007bff;
  color: white;
  padding: 40px 0 20px;
  text-align: center;
  border-bottom: 1px solid #ccc;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.05);
}

header h1 {
  margin: 0 0 10px;
  font-size: 2.2em;
}

header p {
  font-size: 1em;
  margin: 0;
}

.nav {
  display: flex;
  justify-content: center;
  gap: 30px;
  background-color: #ffffff;
  padding: 12px 0;
  border-bottom: 1px solid #e0e0e0;
}

.nav a {
  text-decoration: none;
  color: #007bff;
  font-weight: 600;
  transition: color 0.2s;
}

.nav a:hover {
  text-decoration: underline;
  color: #0056b3;
}

main section {
  margin-top: 40px;
  background: #fff;
  padding: 30px;
  border-radius: 10px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

main h2 {
  color: #007bff;
  font-size: 1.5em;
  margin-bottom: 20px;
}

ol {
  padding-left: 20px;
}

footer {
  margin-top: 60px;
  text-align: center;
  font-size: 0.9em;
  color: #777;
  padding-bottom: 20px;
}

@media (max-width: 600px) {
  .nav {
    flex-direction: column;
    gap: 10px;
  }

  main section {
    padding: 20px;
  }

  header h1 {
    font-size: 1.6em;
  }
}