You can change the % accordingly. Right now it is set to 50% in your store. Keep in mind that the text is aligned to the left by default. If you want to center the text and images in the post you will have to add the following (it can go in the above style tag):
Library Selections is a list of wines that are generally admired and in demand by consumers who want to drink wine already aged to perfection. Most wines in this category will be at least 15 years old, be from iconic regions, iconic producers and highly rated vintages.