An image says more than a thousand words so... I have a horizontal Panel with 3 elements in it. The first Panel should be aligned to the left side and have a fixed width. The last Panel should be aligned to the right side and have a fixed width. The middel Panel should fill the remaining space in the center . I tried a long time but unfortunately I can't get it to work. I have a hard time beleiving that something so simple is hard (or maybe even impossible?) in unitys UI System. I know that this can be accomplished when setting all the values explicitly, but that won't allow me to easily change the padding, resize the first or last block, ... so I would like to know what the correct way of doing this is.