.overlayError {
  
  position: fixed; top:0; left:0; width:100%; height:100%;
  background-color: rgba(0,0,0,.4); 
  display:none; 
  justify-content:center; 
  align-items:center;
  z-index:1000;
}

.overlay-content {
  width:400px; height:auto; background:white; border-radius:10px; padding:40px;
  box-shadow:0 4px 20px rgba(0,0,0,.3); text-align:center;
  display:flex; flex-direction:column; justify-content:center;
}
.overlay-content h1 { font-size:2em; color:#004080; margin-bottom:20px; }
.overlay-content p { font-size:1.2em; color:#333; margin-bottom:30px; }
.gelezen-button { background:#004080; color:white; border:none; padding:12px 24px; border-radius:6px; cursor:pointer; font-size:16px; transition: background .3s ease; }
.gelezen-button:hover { background:#0066cc; }