body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  line-height: 1.6;
  color: #333;
  padding: 20px;
  max-width: 800px;
  margin: 0 auto;
}
h1, h2, h3 { color: #1a1a1a; }
img {
  max-width: 100%;
  border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}
iframe {
  width: 100%;
  aspect-ratio: 16/9;
  border: none;
  border-radius: 8px;
}