When the catalog panel is docked at one side of your screen, you can make it narrower or wider by simply clicking and dragging its edges. If you have moved the catalog panel away from the edge, so it is free-floating, you can resize it by clicking and dragging its corners.
To resize the catalog panel if it is docked:
Position your pointer over the panel's left outside edge. (If you have moved the catalog panel to the left side of the screen, position your pointer over the right edge.) Watch for the Resize cursor to appear.
Click and drag the edge of the panel to stretch it in the desired direction.
Release your mouse button.
To resize the catalog panel if it is free-floating:
Position your pointer over one of the panel’s corners.
Click and drag to stretch the panel.
Release your mouse button.