Title hover on mobile version os the site

Hello,

On this page : https://www.maisonhesper.com/foodportfolio I have a title on "hover" 

But it seams that this over is not display on the mobile version of the site. I tried to change the design on the mobile version for it yo be dispplayed below the image on mobile, but then when i change the design in the mobile it also changes it on the desktop.

What can I do ? Thanks

You can use this code to Website > Website Tools > Custom CSS

@media screen and (max-width:767px) {
a.grid-item {
    height: unset !important;
    padding-bottom: 0 !important;
}
.portfolio-text {
    position: relative !important;
    opacity: 1 !important;
}
    h3.portfolio-title {
        color: #000 !important;
    }
}