#popup-ad, #popup-preview div {
  position: fixed;
  z-index: 9999;
  background: #fff;
  border: 2px solid #333;
  border-radius: 10px;
  box-shadow: 0 5px 20px rgba(0,0,0,0.3);
  padding: 10px;
  display: flex;
  justify-content: center;
  align-items: center;
}
#popup-ad img, #popup-preview img {
  max-width: 250px;
  border-radius: 8px;
}
.popup-close {
  position: absolute;
  top: 3px;
  right: 8px;
  cursor: pointer;
  font-weight: bold;
}

.popup-top-left { top: 20px; left: 20px; }
.popup-top-right { top: 20px; right: 20px; }
.popup-bottom-left { bottom: 20px; left: 20px; }
.popup-bottom-right { bottom: 20px; right: 20px; }
.popup-center { top: 50%; left: 50%; transform: translate(-50%, -50%); }