perkeep/server/camlistored/newui/blob_item_container.css

.cam-blobitemcontainer {
  outline: 0;  /* Do not show an outline when container has focus. */
  border-width: 2px;
  border-color: rgba(0, 0, 0, 0);
  border-style: dashed;
}
.cam-blobitemcontainer-dropactive {
  border-color: #acf;
}