<style>
.block_chuadangnhap.inpop {
    -webkit-transition: max-height 2s;
    -moz-transition: max-height 2s;
    -o-transition: max-height 2s;
    transition: max-height 2s;
    max-height: 91%;
    border-top: 3px solid #8fc839;
    overflow: scroll;
}
</style>