Here’s a quick tutorial to show you how to center your page tabs in Blogger. This technique only works if you’re using the “Pages” gadget.
Note: Please backup your template before making any changes.
Here’s an example of what we’ll be doing in this tutorial. This template shows how your page tabs will look centered.

1. In your Dashboard click on Template.

2. Click on Customize.

3. In the template designer, click on Advanced and then Add CSS and add the following code to the box:
.PageList {text-align:center !important;} .PageList li {display:inline !important; float:none !important;}

4. Be sure to press enter after you paste the code. Finally click on Apply to Blog in the upper right hand corner and you’re done.