body {
  font-family: sans-serif;
}

.modal-ok, .modal-close {
  float: right;
  margin-left: 10px;
}
  
.modal {
  display: none;
  align-items: center;
  justify-content: center;
  position: fixed;
  z-index: 1;
  width: 100%;
  height: 100%;
}
.modal[open] {
  display: flex;
}
.modal-inner {
  background-color: #604040;
  max-width: 600px;
  padding: 10px;
  margin: auto;
  border: 2px solid #805050;
  border-radius: 12px;
}
.modal-header {
  *background-color: green;
  height: 60px;
  display: flex;
  align-items: center;
  justify-content: center;
  *border-bottom: 2px solid #808080;
}
#modal-overlay {
  width: 100%;
  height: 100%;
  position: fixed;
  top: 0;
  left: 0;
  z-index: 0;
  background-color: black;
  opacity: 0.5;  
}