body {
  margin: 0;
  font-family: Arial, sans-serif;
}

/* ----- NAV ----- */
.nav {
  background: #2f3e2f;
  color: white;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 30px;
}

.nav ul {
  list-style: none;
  display: flex;
  gap: 15px;
  margin: 0;
}

.nav a {
  color: white;
  text-decoration: none;
}

/* ----- GRID CENTRAL ----- */
.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  padding: 30px;
}

.card {
  border: 1px solid #ccc;
  padding: 20px;
  text-align: center;
}

/* ----- FOOTER ----- */
.footer {
  background: #2f3e2f;
  color: white;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  padding: 20px;
  text-align: center;
}

/* ===== MEDIANO ===== */
@media (max-width: 900px) {
  .grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .footer {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ===== PEQUEÑO ===== */
@media (max-width: 600px) {
  .grid {
    grid-template-columns: 1fr;
  }

  .footer {
    grid-template-columns: 1fr;
  }

  .nav {
    flex-direction: column;
  }

  .nav ul {
    flex-direction: column;
    align-items: center;
  }
}