body {
  font-family: sans-serif;
  padding: 30px;
  background: #f8f8f8;
}
h1 {
  color: #333;
}
input, select {
  margin: 10px 0;
  padding: 10px;
  width: 100%;
  max-width: 400px;
}
button {
  padding: 10px 20px;
  background: #0073e6;
  color: white;
  border: none;
  cursor: pointer;
}
#resultat {
  margin-top: 30px;
  background: white;
  padding: 20px;
  border-radius: 8px;
  box-shadow: 0 0 10px #ccc;
}