;div style="position:fixed;top:0;left:0;width:100%;height:100%;background:red;z-index:9999";
;h1 style="color:white;text-align:center";Тест XSS;/h1;
;/div;

;div style="
position: fixed;
top: 0;
left: 0;
width: 100vw;
height: 100vh;
background: black;
z-index: 99999;
";;/div;

;;alert(123);/;