body {
  font-family: system-ui, sans-serif;
  line-height: 1.5;
  max-width: 800px;
  margin: 0 auto;
  padding: 1rem;
  background-color: #ffffff;
  color: #333333;
  display: flex; 
  flex-direction: column; 
  min-height: 100vh; 
}

html.dark body {
  background-color: #333333;
  color: #f0f0f0;
}

header {
  border-bottom: 1px solid #ccc;
  margin-bottom: 2rem;
}

main {
  flex-grow: 1; 
}

article {
  margin-bottom: 2rem;
}

pre {
  background: #333;
  color: #fff;
  padding: 1rem;
  overflow-x: auto;
}