center a modal dialog on resize

[greghila]

I need to center a modal dialog when is displayed and when windows is resized.

How can I achieve that?

[greghila]

I got some css

.ui-dialog {
width: 50%;
position: fixed;
top: 50%;
left: 50%;
transform: translate(50%, -50%);
}

which does the trick but somehow when the window is resized, the dialog moves to the right side and stays there rather than staying on the center.