1. Settings: Tools--Options--Environment--Font and Color: Font Size: 12; Background Color: Silver
2. Line numbers are required: vs2015 displays line numbers by default, vs2012 does not display line numbers, its settings: Tools - Options - Style Editor - Select the language you use below, and check it in the right pane Check it off.
3. Temporarily adjust the editing text size: hold down the Ctrl key + scroll the mouse wheel.