CSS code within pages

[GLagrow]

I use an organizations hosting account where they do not allow us to add directories or sub folders within our account. So no chance of using /filemenu. I can put source code within our page only. Will CSS code work within these pages?

Follow up: If I am able to persuade them to create the folder, my intent is to create menus for several of my upscale vendors that I sell the most and each has a business page. As I make new menus and modify the contents from time to time, will I have to have hosting support upload new files each time?