.outer {

         overflow-x: hidden;

         overflow-y: auto;

         text-align: center;

         position: fixed;

         top: 0;

         left: 0;

         bottom: 0;

         right: 0;

    }

    .outer:after {

         content: "\a0 ";

         position: relative;

         display: inline-block;

         vertical-align: middle;

         top: 0px;

         left: 0px;

         width: 0px;

         height: 100%;

    }

    .inner {

         display: inline-block;

         vertical-align: middle;

         width: 70%;

         min-height: 100px;

         background: red;

    }