<img class="thumbnail " src="/UploadFiles/2023-10/111.png" />

<style>

.thumbnail {

cursor: pointer;

}

#overlay {

display: none;

position: fixed;

top: 0;

left: 0;

width: 100%;

height: 100%;

background-color: rgba(0,0,0,0.7);

text-align: center;

}

#overlay img {

margin-top: 20%;

max-width: 100%;

max-height: 100%;

}

</style>

<div id="overlay"><img /></div>

<img class="thumbnail " src="/UploadFiles/2023-10/111.png" />

<script>

function showOverlay(imageUrl) {

var overlay = document.getElementById('overlay');

var image = overlay.querySelector('img');

image.src = imageUrl;

overlay.style.display = 'block';

}

function hideOverlay() {

document.getElementById('overlay').style.display = 'none';

}

</script>