.hidden {
  display: none !important;
}

#loader-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(255, 255, 255, 0.8);
  display: none; /* Oculto por defecto */
  justify-content: center;
  align-items: center;
  z-index: 9999;
}

.spinner {
  width: 50px;
  height: 40px;
  text-align: center;
  font-size: 10px;
}

.spinner > div {
  background-color: #333;
  height: 100%;
  width: 6px;
  display: inline-block;
  -webkit-animation: sk-stretchdelay 1.2s infinite ease-in-out;
  animation: sk-stretchdelay 1.2s infinite ease-in-out;
}

.spinner .rect2 { animation-delay: -1.1s; }
.spinner .rect3 { animation-delay: -1.0s; }
.spinner .rect4 { animation-delay: -0.9s; }
.spinner .rect5 { animation-delay: -0.8s; }

@-webkit-keyframes sk-stretchdelay {
  0%, 40%, 100% { -webkit-transform: scaleY(0.4) }  
  20% { -webkit-transform: scaleY(1.0) }
}

@keyframes sk-stretchdelay {
  0%, 40%, 100% { transform: scaleY(0.4); }
  20% { transform: scaleY(1.0); }
}