Suddenly my gmail screen became small, 1/2 of the normal. I cannot see the subject of the emails I am receiving. Like the page is cut half. Ot the top right corner the tool(-) to make the screen small it is there and it is working. The other one, that allows me to make it big the full screen size, is not working. I can now only exit or make it really small but active. Can you help me to have the default again?