DIV在整個頁面居中

.content {
    width: 428px;
    height: 528px;
    border: 1px solid red;
    position: absolute;
    top: 50%;
    left: 50%;
    border-radius: 12px;
    transform: translate(-50%, -50%);
    -webkit-transform: translate(-50%, -50%);
    -moz-transform: translate(-50%, -50%);            
}