.menu-principal {
  display: flex;
  justify-content: center;
  gap: 2rem;
  background: #003366;
  padding: 1rem;
  position: sticky;
  top: 0;
  z-index: 10;
}

.menu-principal a {
  color: white;
  text-decoration: none;
  font-weight: bold;
  font-size: 1.1rem;
  transition: all 0.3s;
}

.menu-principal a:hover {
  color: white;
}

header {
  text-align: center;
  padding: 1rem 0;
}

footer {
  text-align: center;
  padding: 1rem 0;
  background: #003366;
  color: white;
}

@media (max-width: 600px) {
  .menu-principal {
    flex-direction: column;
    align-items: stretch;
    gap: 0.5rem;
  }

  .menu-principal a {
    padding: 0.5rem;
    text-align: center;
    background: rgba(255,255,255,0.1);
    border-radius: 5px;
  }
}