body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  background-color: #f5f5f5;
  color: #333;
  margin: 0;
  padding: 0;
}

header, footer {
  background-color: #16a085;
  color: #fff;
  text-align: center;
  padding: 1rem;
}

main {
  max-width: 700px;
  margin: 2rem auto;
  padding: 0 1rem;
}

.seccion {
  margin-bottom: 3rem;
  text-align: center;
}

button {
  padding: 0.7rem 1.5rem;
  font-size: 1rem;
  margin-top: 1rem;
  margin-bottom: 1rem;
  background-color: #16a085;
  color: #fff;
  border: none;
  cursor: pointer;
  border-radius: 6px;
  transition: background-color 0.3s;
}

button:hover {
  background-color: #0e7760;
  box-shadow: 0px 4px 12px rgba(0, 0, 0, 0.4);
}

.inputs {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: center;
  margin-top: 1rem;
}

.inputs input {
  padding: 0.5rem;
  font-size: 1rem;
  width: 45%;
}

.botones-opciones {
  margin-top: 1rem;
}

.resultado {
  font-size: 2rem;
  font-weight: bold;
  margin-top: 1rem;
  min-height: 2.5rem;
  transition: opacity 0.4s ease;
}

.fade {
  animation: fadeIn 0.4s ease-in-out;
}

@keyframes fadeIn {
  from { opacity: 0; transform: scale(0.95); }
  to { opacity: 1; transform: scale(1); }
}

hr {
  margin: 4rem 0;
  border: none;
  border-top: 1px solid #ccc;
}

@media screen and (max-width: 600px) {
  .inputs input {
    width: 100%;
  }
}