#modal {
position:fixed;
left:50%;
top:50%;
transform:translate(-50%, -50%);
border:solid 1px #000;
display:none;
background-color:#fff;
}
#overlay {
position:fixed;
left:0;
top:0;
width:100vw;
height:100vh;
display:none;
background-color:#000;
opacity:0.5;
}
function openModal() {
$("#overlay").css({"display":"block"});
$("#modal").css({"display":"block"});
}