* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #f2f4f7;
  color: #222;
}

.conteneur {
  max-width: 500px;
  margin: 40px auto;
  padding: 25px;
  background: white;
  border-radius: 15px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.12);
}

h1 {
  text-align: center;
  margin-bottom: 10px;
}

.info {
  text-align: center;
  color: #555;
}

.timer {
  text-align: center;
  margin: 20px 0;
  padding: 12px;
  border-radius: 10px;
  background: #eef2ff;
}

label {
  display: block;
  margin-top: 15px;
  margin-bottom: 6px;
  font-weight: bold;
}

select,
input,
button {
  width: 100%;
  padding: 12px;
  border-radius: 8px;
  font-size: 16px;
}

select,
input {
  border: 1px solid #bbb;
  background: white;
}

button {
  margin-top: 22px;
  border: 0;
  background: #2563eb;
  color: white;
  cursor: pointer;
  font-weight: bold;
}

button:hover {
  background: #1d4ed8;
}

button:disabled {
  background: #999;
  cursor: not-allowed;
}

.message {
  margin-top: 18px;
  padding: 12px;
  border-radius: 8px;
  text-align: center;
  display: none;
}

.succes {
  display: block;
  background: #dcfce7;
  color: #166534;
}

.erreur {
  display: block;
  background: #fee2e2;
  color: #991b1b;
}

.demo {
  margin-top: 25px;
  font-size: 12px;
  color: #777;
  text-align: center;
}