body {
  font-family: Arial, sans-serif;
  background: #f5f5f5;
  color: #333;
  margin: 0; padding: 0;
}
header, footer {
  background: #222; color: #fff; padding: 1em; text-align: center;
}
main { padding: 2em; max-width: 800px; margin: auto; background: #fff; border-radius: 10px; box-shadow: 0 2px 8px rgba(0,0,0,0.1); }
h1 { color: #c00; }
button, input[type=submit] {
  background: #c00; color: #fff; border: none; padding: 10px 20px; border-radius: 5px; cursor: pointer;
}
button:hover, input[type=submit]:hover { background: #900; }
a { color: #c00; text-decoration: none; }
a:hover { text-decoration: underline; }