动态生成了一个图片，并想让屏幕模糊效果，点击屏幕空白处图片消失，该怎么做？

function showCert(){
           
        var oCert = document.createElement("div");
        oCert.id = "cert";
        oCert.style.height = 700+'px';
        oCert.style.width = 490+'px';
        oCert.style.zIndex = 2222;
        oCert.style.margin = "0 auto";
        var oImg = document.createElement("img");
        oImg.src = "${resourceRoot }/web/ybb/assets/img/main/about2.png";
        oCert.appendChild(oImg);
        document.getElementById('headCert').appendChild(oCert);
        
  };

---

给body或者container设置filter模糊效果?
https://developer.mozilla.org...