.activity-fav-star {
  position: absolute;
  top: 8px;
  right: 8px;
  width: 26px;
  height: 26px;
  border-radius: 50%;
  background: rgba(0, 0, 0, 0.55);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  cursor: pointer;
  z-index: 2;
  transition: background 0.15s ease;
}
.activity-fav-star:hover { background: rgba(0, 0, 0, 0.75); }
.activity-fav-star.active { color: #facc15; }