It is possible to control font size using your browser.

With the Firefox browser pressing the Control key (CTRL) and the Plus key (+) enlarges the font size. Pressing the Control key (CTRL) and the Minus key (-) reduces the font size.

With the Internet Explorer browser click on View on the menu bar at the top of the screen. Then click on Text Size and select the desired font size. The CTRL key trick mentioned above also works with Internet Explorer 8.