/* Fuente moderna */
body {
  font-family: "Segoe UI", Roboto, Arial, sans-serif;
  margin: 0;
  background: #fdfdfd;
  color: #333;
  line-height: 1.6;
}

/* Hero principal */
.hero {
  position: relative;
  background: url("https://picsum.photos/1600/600?blur") no-repeat center center/cover;
  height: 90vh;
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
}
.hero .overlay {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: rgba(0, 51, 102, 0.6);
}
.hero-content {
  position: relative;
  z-index: 2;
}
.hero h1 {
  font-size: 3rem;
  margin-bottom: 10px;
}
.hero p {
  font-size: 1.2rem;
  margin-bottom: 20px;
}

/* Navegación */
nav ul {
  list-style: none;
  padding: 0;
  display: flex;
  justify-content: center;
  gap: 20px;
}
nav ul li a {
  color: white;
  text-decoration: none;
  font-weight: bold;
  transition: color 0.3s;
}
nav ul li a:hover {
  color: #ffcc00;
}

/* Tarjetas */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 25px;
  padding: 40px;
}
.card {
  background: white;
  padding: 25px;
  border-radius: 12px;
  box-shadow: 0 5px 20px rgba(0,0,0,0.1);
  transition: transform 0.3s, box-shadow 0.3s;
}
.card:hover {
  transform: translateY(-8px);
  box-shadow: 0 10px 30px rgba(0,0,0,0.15);
}
.card h2 {
  margin-top: 0;
  color: #003366;
}
.card p {
  color: #555;
}

/* Botón */
.btn {
  display: inline-block;
  margin-top: 15px;
  padding: 10px 20px;
  background: #003366;
  color: white;
  border-radius: 8px;
  text-decoration: none;
  transition: background 0.3s;
}
.btn:hover {
  background: #0055aa;
}

/* Subpáginas */
.sub-hero {
  background: #003366;
  color: white;
  text-align: center;
  padding: 30px;
}
.sub-hero h1 {
  margin: 0 0 15px 0;
}
.sub-hero nav ul {
  justify-content: center;
}
.sub-hero nav ul li a {
  color: #ffcc00;
}

/* Contenido */
.content {
  padding: 40px;
  max-width: 800px;
  margin: auto;
}
.content h2 {
  color: #003366;
}

/* Footer */
footer {
  background: #003366;
  color: white;
  text-align: center;
  padding: 15px;
  margin-top: 40px;
}

/* Responsivo */
@media (max-width: 768px) {
  .hero h1 {
    font-size: 2rem;
  }
  .cards {
    grid-template-columns: 1fr;
  }
}