<div class="modal-wrapper">
<div class="modal-window">
.........
</div>
<div class="overlay"></div>
</div>
<style>
.modal-wrapper {
position:fixed;
display:flex;
width:100%;
height:100%;
justify-content:center;
align-items:center;
background:rgba(0,0,0,.7);
z-index:100;
}
.overlay {
position:absolute;
width:100%;
height:100%;
z-index:1;
}
.modal-window {
width:300px;
height:500px;
z-index:2;
}
</style>
for (let i = 0; i < slider_btn.length; i++) {
slider_btn[i].addEventListener("click", function() {
slid(i);
})
}