How to load the css stylesheets ‘dynamically’ ?

[eluser]saby[/eluser]
Hi
I need some explications
This is my view's structure
Layout.php who included
Header.php
Menu.php
content
Footer.php

In the root, an assets folder with subfolders : css, javascript …

My question:
How to load the css stylesheets ‘dynamically’, i mean
for exemple :
when my content = contact.php, load contact.css
then
when my content = services.php, load services.css

I search since this morning, I tried many things, but i am lost.
thanks a lot