* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}
button {
  cursor: pointer;
}
.modal {
  position: absolute;
  inset: 0;
  display: none;
}

.modal .overlay {
  position: absolute;
  inset: 0;
  background: #33333370;
}

.modal .modal-inner {
  width: 80%;
  margin: 0 auto;
  padding: 20px;
  position: absolute;
  top: 5%;
  left: 0;
  right: 0;
  background: #fff;
  border: 1px solid #33333330;
  z-index: 1;
}

.modal .modal-inner .modal-header {
  margin-bottom: 16px;
  border-bottom: 1px solid #333;
}

.modal .modal-inner .modal-header h2 {
  display: inline-block;
  padding-bottom: 12px;
}

.modal .modal-inner .modal-header .close-btn {
  padding: 4px;
  float: right;
  font-size: 16px;
  font-weight: 500;
  cursor: pointer;
}
.modal .modal-inner .modal-header .close-btn:hover {
  color: red;
  outline: 1px solid #ddd;
}

.modal .modal-inner .modal-header .close-btn::after {
  content: "";
  display: block;
  clear: both;
}

input:checked ~ .modal {
  display: block;
}