[CSS] popup window with dimmed background

.blackout {
background-color:#000;
opacity:.7;
filter:alpha(opacity=70);
height:100%;
width:100%;
position:fixed;
top:0;
left:0;
z-index:100;
display:none;
cursor:pointer;
}



출처 :
http://displayhelloworld.blogspot.kr/2013/01/pop-out-window-with-dim-background.html