body {
  font-family: Arial, sans-serif;
  background: #f4f7fb;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  margin: 0;
}

.payment-box {
  background: white;
  padding: 30px;
  width: 360px;
  border-radius: 14px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.1);
  text-align: center;
}

.payment-box h2 {
  margin-bottom: 20px;
  color: #222;
}

.payment-box input {
  width: 100%;
  padding: 12px;
  margin: 8px 0;
  border: 1px solid #ddd;
  border-radius: 8px;
  box-sizing: border-box;
}

.payment-box button {
  width: 100%;
  padding: 12px;
  background: #0b72ff;
  color: white;
  border: none;
  border-radius: 8px;
  margin-top: 12px;
  cursor: pointer;
  font-size: 16px;
}

.payment-box button:hover {
  background: #005bd1;
}

#message {
  margin-top: 15px;
}