Cell contents have all moved to the right of the cell

While working on a spreadsheet with a cell selected, I accidentally hit the Update in Text/Table Style 1 (I have a trackpad). I only know because there was an Update box and now it's no longer there. ALL the cell contents have shifted to the right within the cell (both numbers and text). However, there is a huge space on the left which just cannot be used. The spreadsheet has 7 tabs and in ALL of them this has occurred too.

In the screenshot below, text is centre aligned and numbers are right aligned. But as one can see, whether inputting numbers or text, a good portion of the cell is just unusable.

I have never messed with Styles, and if this has to do with Style, what is to be done?