.popup-close {
  position: absolute;
  top: -54px;
  right: 6px;
  width: 36px;
  height: 36px;
  border: none;
  background: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(6px);
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.25s ease;
}

.popup-close::before,
.popup-close::after {
  content: "";
  position: absolute;
  width: 18px;
  height: 2px;
  background-color: #fff;
  border-radius: 1px;
  transition: background 0.25s ease, transform 0.25s ease;
}

.popup-close::before {
  transform: rotate(45deg);
}

.popup-close::after {
  transform: rotate(-45deg);
}

.popup-close:hover {
  background: rgba(96, 165, 163, 0.9); /* твой фирменный #60a5a3 */
  transform: rotate(90deg);
}

.popup-close:hover::before,
.popup-close:hover::after {
  background-color: #fff;
}