body {
  font-family: Arial, sans-serif;
  margin: 0;
  background: #f5f5f5;
}

header, section, footer {
  padding: 20px;
  text-align: center;
}

.hero {
  background: #111;
  color: white;
}

.btn {
  display: inline-block;
  padding: 10px 20px;
  margin: 10px;
  background: #0070f3;
  color: white;
  text-decoration: none;
  border-radius: 4px;
}

.btn.secondary {
  background: #555;
}

input, select, textarea {
  width: 100%;
  max-width: 400px;
  margin: 6px auto;
  padding: 8px;
  display: block;
}

iframe {
  width: 100%;
  max-width: 600px;
  height: 300px;
  border: 0;
}
``