#popup_gallery {
  display: none;          
  opacity: 0;             
  position: fixed;
  z-index: 9999;
  top: 0; left: 0;
  width: 100%; height: 100%;
  background: rgba(0, 0, 0, 0.95);
  text-align: center;
  transition: opacity 0.3s ease;
}

#popup_gallery.show {
  display: block;
  opacity: 1;
}

#popup_gallery img {
  max-width: 90%;
  max-height: 90%;
  margin: auto;
  position: absolute;
  top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  border-radius: 8px;
  box-shadow: 0 0 20px rgba(0,0,0,0.8);
  transition: opacity 0.3s ease;
}

#popup_gallery .close {
  position: absolute;
  top: 20px;
  right: 35px;
  color: #fff;
  font-size: 40px;
  font-weight: bold;
  cursor: pointer;
  transition: color 0.3s;
}
#popup_gallery .close:hover {
  color: #e99900;
}

#popup_gallery .prev,
#popup_gallery .next {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  color: #fff;
  font-size: 60px;
  font-weight: bold;
  cursor: pointer;
  user-select: none;
  padding: 10px;
  transition: color 0.3s;
}
#popup_gallery .prev { left: 20px; }
#popup_gallery .next { right: 20px; }

#popup_gallery .prev:hover,
#popup_gallery .next:hover {
  color: #e99900;
}