body {
  font-family: Arial, sans-serif;
  max-width: 800px;
  margin: auto;
  padding: 20px;
  line-height: 1.6;
}
h1, h2 {
  color: #333;
}
code {
  background: #f4f4f4;
  padding: 2px 5px;
  border-radius: 3px;
}
pre {
  background: #f4f4f4;
  padding: 10px;
  overflow-x: auto;
  border-radius: 5px;
}
label, select {
  margin-right: 10px;
}
.hidden {
  display: none;
}