static/style.css

body {
  font-family: Arial, sans-serif;
  background: #111;
  color: #eee;
  text-align: center;
  padding: 40px;
}

.container {
  background: #222;
  padding: 30px;
  border-radius: 10px;
  display: inline-block;
}

input, select, button {
  margin: 10px;
  padding: 10px;
  font-size: 1em;
}