.rg {
  max-width: 980px;
  margin: 0 auto;
  padding: 2rem 1rem 3rem;
}
.rg__volver {
  color: var(--t-accent);
  text-decoration: none;
  font-size: .9rem;
  display: inline-block;
  margin-bottom: 1rem;
}
.rg__volver:hover { text-decoration: underline; }

.rg h1 { color: var(--t-text); margin-bottom: .4rem; }
.rg__intro { color: var(--t-muted); line-height: 1.6; margin-bottom: 1.25rem; max-width: 620px; }

.rg__filtros { display: flex; gap: .5rem; flex-wrap: wrap; margin-bottom: 2rem; }
.rg__filtro {
  border: 1px solid var(--t-line);
  border-radius: 999px;
  padding: .4rem .9rem;
  font-size: .85rem;
  font-weight: 600;
  color: var(--t-text);
  text-decoration: none;
  min-height: 36px;
  display: inline-flex;
  align-items: center;
}
.rg__filtro:hover { border-color: var(--t-accent); color: var(--t-accent); }
.rg__filtro--activo { background: var(--t-accent); border-color: var(--t-accent); color: #fff; }

.rg__bloque { margin-bottom: 2.25rem; }
.rg__nivel-titulo { color: var(--t-accent); font-size: 1.1rem; margin-bottom: 1rem; }

.rg__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1rem;
}
.rg__tarjeta {
  background: var(--t-panel);
  border: 1px solid var(--t-line);
  border-radius: 14px;
  padding: 1.25rem;
  transition: transform .16s ease, box-shadow .16s ease, border-color .16s ease;
}
.rg__tarjeta:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(0,0,0,.07);
  border-color: var(--t-accent-mid, var(--t-accent));
}
.rg__tarjeta h3 { font-size: 1rem; color: var(--t-text); margin: 0 0 .6rem; }
.rg__explicacion { color: var(--t-muted); font-size: .9rem; line-height: 1.55; margin: 0 0 .8rem; }
.rg__ejemplo {
  background: var(--t-bg);
  border-radius: 10px;
  padding: .6rem .8rem;
}
.rg__ejemplo-en { display: block; color: var(--t-text); font-size: .88rem; }
.rg__ejemplo-es { display: block; color: var(--t-muted); font-size: .8rem; margin-top: .2rem; }

.rg__vacio { color: var(--t-muted); }

@media (prefers-reduced-motion: reduce) {
  .rg__tarjeta { transition: none; }
  .rg__tarjeta:hover { transform: none; }
}

@media (max-width: 480px) {
  .rg { padding: 1.25rem .75rem 2rem; }
  .rg__grid { grid-template-columns: 1fr; }
}