body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  line-height: 1.5;
  background: #fafafa;
}
nav a {
  text-decoration: none;
  color: #333;
  font-weight: bold;
}
nav a:hover {
  color: #007BFF;
}
.container {
  max-width: 600px;
  margin: 2em auto;
  padding: 1em;
  background: #fff;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
  border-radius: 8px;
}
input, button {
  font-size: 1em;
  padding: 0.5em;
  margin: 0.5em 0;
  border: 1px solid #ccc;
  border-radius: 4px;
}
button {
  background: #007BFF;
  color: #fff;
  cursor: pointer;
  border: none;
}
button:hover {
  background: #0056b3;
}
pre {
  background: #f0f0f0;
  padding: 1em;
  border-radius: 4px;
  overflow-x: auto;
}