Question 6 :
What is a Style Sheet?
Style sheets are the way that standards-compliant Web designers define the layout, look-and-feel, and design of their pages. They are called Cascading Style Sheets or CSS. With style sheets, a designer can define many aspects of a Web page:
Style sheets give you a lot of power to define how your pages will look. And another great thing about them is that style sheets make it really easy to update your pages when you want to make a new design. Simply load in a new style sheet onto your pages and you're done.
Question 7 :
Which browsers support CSS?
It depends on your definition of "support." If you are interested in those browsers which makes some attempt at supporting CSS, no matter how partial or bug-ridden, then the list is:
* Internet Explorer 3.0 and above
* Navigator 4.0 and above
* Opera 3.6 and above
* XPublish by Media Design inÂ·Progress
If instead you're interested in those browsers which are known to do a credible job of bug-free and mostly completel support for CSS1, then the list narrows somewhat dramatically:
* Internet Explorer 5.0 for Macintosh and above
* Internet Exporer 5.5 for Windows and above
* Netscape Navigator 6.0 and above
* Opera 4.0 and above
While none of these browser can be claimed to have a perfect implementation of CSS1, they are all quite good and can be relied upon to operate in a consistent fashion for most of CSS1.
Question 8 :
Which set of definitions, HTML attributes or CSS properties, take precedence?
CSS properties take precedence over HTML attributes. If both are specified, HTML attributes will be displayed in browsers without CSS support but won't have any effect in browsers with CSS support.
Question 9 :
Why call the subtended angle a "pixel", instead of something else (e.g. "subangle")?
In most cases, a CSS pixel will be equal to a device pixel. But, as you point out, the definition of a CSS pixel will sometimes be different. For example, on a laser printer, one CSS pixel can be equal to 3x3 device pixels to avoid printing illegibly small text and images. I don't recall anyone ever proposing another name for it. Subangle? Personally, I think most people would prefer the pragmatic "px" to the non-intuitive "sa".
Question 10 :
Why was the decision made to make padding apply outside of the width of a 'box', rather than inside, which would seem to make more sense?
It makes sense in some situations, but not in others. For example, when a child element is set to width: 100%, I don't think it should cover the padding of its parent. The box-sizing property in CSS3 addresses this issue. Ideally, the issue should have been addressed earlier, though.