body {
  margin: 0
}

.contenedor {
  border: 2px solid black;
  box-shadow: 10px 10px 5px 0px rgba(0, 0, 0, 0.75);
  width: 50%;
  text-align: center;
  margin: 50px auto;
  padding: 25px 50px 50px 50px;
}

button {
  width: auto;
  height: 40px;
  text-decoration: none;
  padding: 10px;
  font-weight: 600;
  font-size: 20px;
  color: #ffffff;
  background-color: #1883ba;
  border-radius: 6px;
  border: 2px solid #0016b0;
  transition: 0.3s;
  margin: 5px;
}

button:hover {
  color: white;
  background-color: green;
  cursor: pointer;
}

.row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
}

@media (max-width: 768px) {
  .row {
    flex-direction: column;
  }
}