.popin {
  display: none;
  position: fixed!important;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 1000;
  background: #fff;
  padding: 20px;
  max-width: 800px;
  width: 90%;
  max-height: 90vh;       /* hauteur max */
  overflow-y: auto;       /* scroll interne */
  box-shadow: 0 4px 20px rgba(0,0,0,0.3);
  border-radius: 8px;
  z-index:999;
}

.popin-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0,0,0,0.5);
  z-index: 998;
}

.popin-close {
  position: absolute;
  top: 10px;
  right: 10px;
  background: none;
  border: none;
  font-size: 20px;
  cursor: pointer;
}