There are certain issues when formatting content to look best across all browser widths. You would naturally use line-breaks (pressing SHIFT + ENTER) on desktop widths to format the text— to make it easier to read. But that doesn't work on mobile. It looks awful when the text wants to naturally flow within its parent container.
In Squarespace, instead of forcing line breaks in your text, just insert SPACER BLOCKS on both sides of your paragraph. They disappear on mobile widths, making them INCREDIBLY AWESOME for tweaks like this.
In the video, I've added a full-wide Spacer Block to "cut the text apart". Then I drag/drop a few more, and make adjustments to center everything.
Squarespace docs on Spacer Blocks (that totally rhymes)