How to set your scale tool
to enlarge all aspects of your art proportionally.
Double-click the Scale tool in Illustrator (you'll find it in the toolbar, nested with the Rotate, Reflect, and Shear tools). Double-click on the Scale tool to open its options palette. Click the checkboxes for Scale Corners and Scale Strokes & Effects. Click on OK to close the palette. Select and watch it enlarge perfectly!