body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 10px 0 0 0;   /* padding arriba */
  display: flex;
  justify-content: center; /* centrado horizontal */
  background: #c2c2c2;
  /*height: 80vh; */         /* alto del contenedor */
  overflow-y: hidden;     /* sin scroll vertical */
}



.contenedor {
  background: white;
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.12);
  max-width: 420px;
  width: 80%;
  text-align: center;
}

h1 {
  font-size: 1.2rem;
  margin-bottom: 5px;
}

h2 {
  font-size: 1rem;
  margin-bottom: 5px;
}


form {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

input[type="number"] {
  padding: 10px;
  border: 1px solid #ccc;
  border-radius: 8px;
  font-size: 1rem;
  width: 100%;
  box-sizing: border-box;
}

.resultado {
  padding: 10px;
  background: #f1f1f6;
  border: 1px solid #ccc;
  border-radius: 8px;
  height: 30px;              /* igual altura que input */
  line-height: 20px;
  font-size: 1rem;
  display: flex;
  align-items: center;
  justify-content: flex-start; /* alinear a la izquierda */
  font-weight: bold;
  box-sizing: border-box;
}


button {
  padding: 12px;
  background: #16a085;
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 1rem;
  cursor: pointer;
  margin-top: 6px;
}

button:hover {
  background: #205248;
}

button[type="button"] {
  background: #777;
}

button[type="button"]:hover {
  background: #555;
}

@media (min-width: 900px) {
  .contenedor {
    max-width: 520px;
  }
}