/* ===== FOOTER ===== */
.footer {
  background-color: #0e0f2e;
  color: #999;
}

/* Copyright */
.copyright {
  background: #0e0f2e;
  color: #fff;
  padding: 25px 0;
  position: relative;
  z-index: 1;
  font-weight: 600;
  font-size: 13px;
  text-align: center;
}

/* Botón “Back to Top” */
.btn-back-top {
  width: 50px;
  height: 50px;
  border-radius: 50%;
  background: transparent;
  border: 2px solid rgba(255, 255, 255, 0.6);
  color: #ffffff;
  font-size: 20px;
  cursor: pointer;
  transition: all 0.3s ease;
  backdrop-filter: blur(6px);
  box-shadow: 0 0 10px rgba(255, 255, 255, 0.1);
}

.btn-back-top:hover {
  background: rgba(255, 255, 255, 0.15);
  border-color: #ffffff;
  transform: translateY(-5px);
  box-shadow: 0 0 20px rgba(255, 255, 255, 0.25);
}

/* Posición del botón */
#back-to-top {
  position: fixed;
  bottom: 25px;
  right: 25px;
  z-index: 100;
  display: none; /* oculto hasta hacer scroll */
}

/* Adaptación para pantallas pequeñas */
@media (max-width: 767px) {
  .btn-back-top {
    width: 42px;
    height: 42px;
    font-size: 18px;
  }
}