body{margin:0;font-family:sans-serif;background:#111;color:#fff;height:100vh;display:flex;align-items:center;justify-content:center;}
.portfolio-list{list-style:none;padding:0;z-index:2;position:relative;}
.portfolio-list li{font-size:3rem;margin:1rem;cursor:pointer;}
#bg-display{position:fixed;top:0;left:0;width:100%;height:100%;background-size:cover;background-position:center;opacity:0;transition:opacity .5s;}