:root {
  --brand: #1e40af;
  --accent: #6366f1;
  --bg: #f8fafc;
  --ink: #0f172a;
  --muted: #5c8ecf;
  --panel: #5c8ecf;
  --line: #e2e8f0;
  --best: #facc15;
  --price: #0f766e;
  --fuente: 'Inter', sans-serif;
}

body {
  margin: 0;
  font-family: var(--fuente);
  background-color: var(--bg);
  color: var(--ink);
}

header {
  background-color: var(--bg);
  border-bottom: 1px solid var(--line);
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  position: sticky;
  top: 0;
  z-index: 1000;
}

.logo img {
  height: 40px;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--brand);
  cursor: pointer;
}

.menu-principal {
  list-style: none;
  display: flex;
  gap: 1rem;
  margin: 0;
  padding: 0;
}

.menu-principal a {
  text-decoration: none;
  color: var(--brand);
  font-weight: 600;
  transition: color 0.3s ease;
}

.menu-principal a:hover {
  color: var(--accent);
}

@media (max-width: 768px) {
  .menu-principal {
    flex-direction: column;
    position: absolute;
    top: 70px;
    right: 0;
    background-color: var(--bg);
    width: 200px;
    padding: 1rem;
    box-shadow: 0 2px 6px rgba(0,0,0,0.1);
    display: none;
  }

  .menu-principal.active {
    display: flex;
  }

  .menu-toggle {
    display: block;
  }
}

.banner {
  background: linear-gradient(to right, var(--brand), var(--accent));
  color: var(--bg);
  padding: 4rem 2rem;
  text-align: center;
}

.btn-acceso {
  background-color: var(--accent);
  color: var(--bg);
  border: none;
  padding: 0.8rem 1.5rem;
  font-size: 1rem;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.3s ease;
}

.btn-acceso:hover {
  background-color: var(--brand);
}

.seccion {
  padding: 3rem 2rem;
  max-width: 1200px;
  margin: auto;
}

.filtros {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
  justify-content: center;
}

.filtro {
  background-color: var(--bg);
  border: 1px solid var(--muted);
  color: var(--brand);
  padding: 0.4rem 1rem;
  border-radius: 20px;
  cursor: pointer;
  font-weight: 600;
  transition: all 0.3s ease;
}

.filtro.activo {
  background-color: var(--brand);
  color: var(--bg);
}

.cursos {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
}

.curso {
  background-color: var(--panel);
  color: var(--ink);
  border-radius: 10px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.1);
  padding: 1rem;
  text-align: center;
  transition: all 0.4s ease;
  position: relative;
}

.curso img {
  width: 100%;
  height: auto;
  border-radius: 8px;
  margin-bottom: 1rem;
}

.etiqueta {
  position: absolute;
  top: 10px;
  left: 10px;
  background-color: var(--best);
  color: var(--ink);
  padding: 0.2rem 0.6rem;
  font-size: 0.75rem;
  border-radius: 4px;
  font-weight: bold;
}

.precio {
  font-weight: bold;
  color: var(--price);
  margin-bottom: 0.5rem;
}

.rating {
  color: var(--best);
  font-size: 1.2rem;
}

footer {
  background-color: var(--ink);
  color: var(--bg);
  padding: 2rem;
  text-align: center;
}

/* Ajustes para pantallas pequeñas */
@media (max-width: 480px) {
  .banner h1 {
    font-size: 1.5rem;
  }

  .banner p {
    font-size: 1rem;
  }

  .btn-acceso {
    font-size: 0.9rem;
    padding: 0.6rem 1.2rem;
  }

  .curso h3 {
    font-size: 1rem;
  }

  .curso .precio,
  .curso .rating {
    font-size: 0.9rem;
  }
}