Hi there,
this will be a feature of the future GB Pro plugin, for the free version add this CSS:
.gb-zoom .gb-grid-column > .gb-container:before {
transform: scale(1);
transition: transform 0.3s ease-in-out;
}
.gb-zoom .gb-grid-column:hover > .gb-container:before {
transform: scale(1.2);
transition: transform 0.3s ease-in-out;
}
Then select the Grid Container ( thats the outer block containing all your grid items) and give it a CSS Class of gb-zoom