From Newbie: I see so many css codings in stylesheet-file, I am wondering which codings controls which page? Is there any particular list of codings order or pattern that it must be written in that sequence only from top to bottom, I mean? Its e-commerce website.
I don't think it matters what order it's written in, but you need to keep it organized. Also, css codings don't control pages, they control tags like <div>, <span>, and other attributes like font sizes, colors, etc.
The order doesn't matter unless you have 2 items that affect the same thing. For example you have this: #container { width:500px; } Code (markup): and then somewhere BELOW it, you have another one like this: #container { width:800px; } Code (markup): So basically both have different widths, although the LAST one will be applied, not the first one. So it'll use 800px. That's the only thing you should be aware of.
usually, it's good to use comment in any kind of file(css, php or js)..to know which part belong to which module or page
I could sit here typing out stuff about divs and classes, but better you just go get the best impression from the pro's http://www.w3schools.com/css/
Alternatively, you could read the actual specifications of HTML and CSS from W3.org (w3schools is not in anyway related to w3.org.) http://www.w3.org/TR/html4/ http://www.w3.org/TR/CSS1