body {
  font-family: Arial, sans-serif;
  background: #f0f0f0;
  margin: 0;
  padding: 20px;
}

.container {
  max-width: 400px;
  margin: 50px auto;
  text-align: center;
  background: white;
  padding: 40px;
  border-radius: 15px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}

h1 { color: #4a90e2; }
#valor { font-size: 4rem; margin: 20px 0; }
button {
  font-size: 1.2rem;
  padding: 10px 20px;
  margin: 5px;
  background: #4a90e2;
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
}
#status { margin-top: 30px; font-weight: bold; }