html {
   height: 100%;
}

body {
   display: -webkit-box;   /* OLD: Safari,  iOS, Android browser, older WebKit browsers.  */
   display: -moz-box;      /* OLD: Firefox (buggy) */
   display: -ms-flexbox;   /* MID: IE 10 */
   display: -webkit-flex;  /* NEW, Chrome 21–28, Safari 6.1+ */
   display: flex;          /* NEW: IE11, Chrome 29+, Opera 12.1+, Firefox 22+ */

   -webkit-box-align: center; -moz-box-align: center; /* OLD… */
   -ms-flex-align: center; /* You know the drill now… */
   -webkit-align-items: center;
   align-items: center;

   -webkit-box-pack: center; -moz-box-pack: center;
   -ms-flex-pack: center;
   -webkit-justify-content: center;
   justify-content: center;
   height: 100%;
   width: 100% /* needed for Firefox */
}


img {
   display: -webkit-box; display: -moz-box;
   display: -ms-flexbox;
   display: -webkit-flex;
   display: flex;

   -webkit-box-align: center; -moz-box-align: center;
   -ms-flex-align: center;
   -webkit-align-items: center;
   align-items: center;



   max-width: 90%;
   max-height: 90%;
   }