The main window should not allowed to be resized to under about a width of about 530 to 550 pixels, or height of less than 360 to 380 pixels. Less than those values and the widgets get over each other (tested on macOS).
Also, if the grid values won't have a longer length, it would be nice to specify a standard maximum width - when the user maximizes the window, it will show everything it has to show without taking too much space.
The same treatment should be also applied to the preferences window, which suffers the same issues.
The main window should not allowed to be resized to under about a width of about 530 to 550 pixels, or height of less than 360 to 380 pixels. Less than those values and the widgets get over each other (tested on macOS).
Also, if the grid values won't have a longer length, it would be nice to specify a standard maximum width - when the user maximizes the window, it will show everything it has to show without taking too much space.
The same treatment should be also applied to the preferences window, which suffers the same issues.