/* when hiding the thing */
/* when hiding the thing */

.tengahke {
                display: block;
                position: absolute;
                top: 50%;
                left: 50%;
                transform: translate(-50%, -50%);
                -webkit-transform: translate(-50%, -50%); /* Safari and Chrome */
                -moz-transform: translate(-50%, -50%); /* Firefox */
                -ms-transform: translate(-50%, -50%); /* IE 9 */
                -o-transform: translate(-50%, -50%);

}