changing the text hover

hello

thanks for this amazing plugin.

i have an issue which i need urgent help with.

i want the data box to be invisible by default and when i hover on it by mouse i want the the data box to appear.

i have tried many things with css but i think im writing something wrong!

this was my last attempt.

div.cactus_masonry_databox div.cm_title
{
	display:none;
}

div.cactus_masonry_databox div.cm_title:hover
{
	display:block;
}

https://ww.wp.xz.cn/plugins/masonry-post-gallery/