I don't understand? Yes you can use CSS with HTML and XHTML. if memory serves correct subsilver.css is a theme for phpBB?
Yes,and it's widely used for php forums therefore,i ask that question,so style sheets can be used with HTML without any effects on SEO(search engines optimization)
Yes, CSS doesn't affect SEO. CSS is just that, a way to style your website... like backgrounds, colors, fonts, font-sizes, etc
If you download CSS, your site will look like a carbon copy of the site that you downloaded it from. CSS isn't just an add-on that you plug inside your webpage or something. CSS defines how your whole webpage looks like. But if you mean free designs/templates, then yeah there are plenty, like www.oswd.org
if you copy paste the css of some other site into your site it wont work like a carbon copy of the site from which you copied , infact it wont work cause the css file used on other file will have different parameters than used in yours.. ofcourse you can get the carbon copy if you modify it little bit. but thats not legal you need to take permission of the owner of the site
So,if i want to use a one like SUBsilver.css,should i learn everything about CSS and make a unique one for my websites? I'm using subsilver.css only for borders In fact,i want to use CSS for borders to organize my websites,is this legal or not?
yeah as long as you make the complete css yourself tyhen its fine.. taking css or site from someone else and saying its made by you is illigeal
no,i will never say that this template is made by me.. so,Should i add a back link to designer of subsilv.css,which i use borders only thanks