You can reduce the size of any snippet block from the default 100% available width to a custom width, and align center, left, right either by drag-drop or by settings in the Style Editor popup.
You can set a specific width for your snippet block by setting the max-width value in the Style Editor Popup. To access the Style Editor, click the red COG icon that shows top-left above the snippet block.
You can resize a column by hovering near the edge of the column.
This will bring up a resize toolbar, clicking this will increase the size of the column, reducing the size of the column next to it to fit.