I made this style for myself to have chat out of the way when it is not needed, but available when I want it. It defaults to having chat hidden and replaced by a partially shaded cyan rectangle on the bottom left of the window, above the pause button. When the rectangle is hovered over, it will show a reasonably large chat window, without negatively affecting the video.

Do note that I made this for myself and to be compatible with the other style I made and use, the Hitbox TV Video Expander @ http://freestyler.ws/style/93545/hitbox-tv-video-expander I actually cannot even get this style to work without that one.