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

/* Fondo celeste institucional detrás del logo y menú */
.fondo-logo {
  background-color: #5c8ecf;
}

.fondo-logo .nav-link {
  color: #f8fafc;
}

.fondo-logo .nav-link.active {
  color: #ffffff; /* ← antes era #facc15 (amarillo) */
}

body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif;
  background-color: var(--bg);
  color: var(--ink);
  margin: 0;
  padding: 0;
}

.navbar-brand {
  font-weight: 800;
  color: var(--brand);
  letter-spacing: .2px;
}

.hero {
  background-color: var(--brand);
  color: #fff;
  padding: 56px 0;
}

.hero .lead {
  opacity: .95;
}

.category-box {
  background: var(--panel);
  border-radius: 12px;
  padding: 20px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.06);
  border: 1px solid var(--line);
  position: sticky;
  top: 16px;
}

.category-title {
  font-weight: 800;
  color: var(--brand);
  font-size: 1.05rem;
  margin-bottom: 14px;
}

.course-list {
  list-style: none;
  padding-left: 0;
  margin: 0;
}

.course-list li {
  padding: 10px 12px;
  border: 1px solid var(--line);
  background-color: #fff;
  border-radius: 10px;
  margin-bottom: 8px;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: background .15s, border-color .15s;
}

.course-list li:hover {
  background-color: #eef2ff;
  border-color: #c7d2fe;
}

.course-list li.active {
  outline: 2px solid var(--accent);
  background: #eef2ff;
}

.pill {
  font-size: .72rem;
  padding: 2px 8px;
  border-radius: 999px;
  background: #e2e8f0;
  color: #334155;
  font-weight: 600;
}

.section-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
}

.section-head h4 {
  margin: 0;
  font-weight: 800;
  color: var(--ink);
  font-size: 1.25rem;
}

.course-box {
  background: #fff;
  border-radius: 12px;
  padding: 18px;
  box-shadow: 0 4px 12px rgba(0,0,0,0.06);
  height: 100%;
  border: 1px solid var(--line);
}

.course-title {
  font-weight: 700;
  color: var(--brand);
  font-size: 1rem;
}

.course-meta {
  font-size: 0.9rem;
  color: var(--muted);
}

.badge-best {
  background-color: var(--best);
  color: #1e293b;
  font-weight: 700;
  border-radius: 6px;
  padding: 3px 8px;
  font-size: 0.72rem;
}

.price {
  font-weight: 800;
  color: var(--price);
}

.old-price {
  text-decoration: line-through;
  color: #94a3b8;
  font-size: 0.9rem;
}

.rating {
  font-size: 0.85rem;
  color: var(--muted);
}

.footer {
  background-color: #1e40af;
  color: #f8fafc;
  padding: 20px 0;
  text-align: center;
  margin-top: 60px;
}

/* Adaptación responsiva para tablets y móviles */
@media (max-width: 991.98px) {
  .category-box {
    position: static;
    margin-bottom: 20px;
  }

  .section-head {
    flex-direction: column;
    align-items: flex-start;
  }

  .navbar-nav {
    margin-top: 10px;
  }

  .navbar-collapse {
    background-color: #5c8ecf;
    padding: 10px;
    border-radius: 0 0 12px 12px;
  }

  .navbar-nav .nav-link {
    padding: 8px 12px;
    font-size: 1rem;
  }
}