* { box-sizing: border-box; margin: 0; padding: 0; }

[hidden] { display: none !important; }

html, body {
  height: 100%;
  background: #fff;
  color: #111;
  font-family: -apple-system, "Segoe UI", Roboto, sans-serif;
  font-size: 20px;
}

#app {
  max-width: 480px;
  margin: 0 auto;
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  gap: 18px;
  text-align: center;
}

.paso {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

button.grande {
  font-size: 1.4rem;
  padding: 20px;
  border: none;
  border-radius: 14px;
  background: #1a1a1a;
  color: #fff;
  cursor: pointer;
  width: 100%;
}

button:active { opacity: .7; }
button:disabled { opacity: .5; }

.estado { font-size: 1.2rem; }

.error { color: #b00020; font-weight: bold; }

input[type="number"] {
  font-size: 2.2rem;
  text-align: center;
  padding: 14px;
  width: 100%;
  border: 2px solid #1a1a1a;
  border-radius: 14px;
}

#qr-resultado {
  width: 100%;
  max-width: 400px;
  margin: 0 auto;
  image-rendering: pixelated;
}