.hidden-wrapper {
    -moz-transform-origin: 0 0;
    -webkit-transform-origin: 0 0;
    -o-transform-origin: 0 0;
    -ms-transform-origin: 0 0;
    transform-origin: 0 0;
    border:1px solid transparent;
}
.hidden-wrapper.off {
    -webkit-transition: all 400ms cubic-bezier(0,1,0,1);
    -moz-transition: all 400ms cubic-bezier(0,1,0,1);
    -ms-transition: all 400ms cubic-bezier(0,1,0,1);
    -o-transition: all 400ms cubic-bezier(0,1,0,1);
    transition: all 400ms cubic-bezier(0,1,0,1);
    max-height: 0;
    opacity: 0;
    overflow: hidden;
}
.hidden-wrapper:not(.off) {
    -webkit-transition: all 600ms ease-in;
    -moz-transition: all 600ms ease-in;
    -ms-transition: all 600ms ease-in;
    -o-transition: all 600ms ease-in;
    transition: all 600ms ease-in;
    max-height: 100000px;
    opacity: 1;
}