How to resize the header of every category.

Which is the css code ?

Sorry, I don't understand what exactly you want to achieve. Please explain more.

If you want to change the font, case, size, spacing for text or color within a placeholder, select the text, click the home tab, and then in the font group and then you can go further by clicking the option you are looking for.

CSS is a Cascading Style Sheets that is mainly used for describing presentation semantics.The specifications of CSS are maintained by World Wide Web Consortium (W3C).

Web Design

if you want few different header in all over the website so you have to make some master pages as per requirement.

check this link hope your problem will solve
http://www.webdesignerdepot.com/2013/03/how-to-create-a-resizing-menu-bar/

If you wanna save these complicated steps and find a easy way, you can google imaging sdk and you will find many useful tools, or google how toresize image to get instructive articles. Good luck:) I think image processing programmes can enable to quickly resize pictures . i have use imaging sdk which can original layouts hyperlinks, Images and tables retained in word ,text, image, Epub, html.but i forgot download the wedsite ,go to google. By the way , pay attention to your system platform, select the suitable one . I use an imaging sdk driver found on the internet . Install it and it becomes a selectable processing option.Then you can resize your images in any program at all, including Adobe Acrobat .zoom in or zoom out on your own will.  Just open the images, select resize ,and follow the setps given in the sdk, the task will be finished in several seconds. if you haven't found a good choice , you can have a try. best wishes.