.custom-checkbox {
  position: relative;
  width: 50px;
  height: 50px;
  border-radius: 6px;
  background-color: #d1e0f2; 
  cursor: pointer;
  transition: background-color 0.3s ease;
  display: inline-block;
  overflow: hidden;
}

.custom-checkbox input[type="checkbox"] {
  opacity: 0;
  width: 0;
  height: 0;
  position: absolute;
}

.custom-checkbox .checkmark {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  color: white;
  font-size: 24px;
  line-height: 1;
  font-weight: bold;
  display: none;
  pointer-events: none;
}

.custom-checkbox input[type="checkbox"]:checked ~ .checkmark {
  display: block;
}

.custom-checkbox:has(input[type="checkbox"]:checked) {
  background-color: #000F6E; /* Тёмно-синий */
}