CSS Secrets

Footnotes

2 Backgrounds & Borders

* Prime numbers are integers that can’t be divided by any other number besides 1 and themselves. For example, the first 10 prime numbers are 2, 3, 5, 7, 11, 13, 17, 19, 23, 29. On the other hand, relatively prime is a relation between numbers, not an attribute of a single number. Relatively prime numbers have no common divisors, but may have many divisors in general (e.g., 10 and 27 are relatively prime, but neither is prime). Of course, a prime number is relatively prime with any other number.

5 Typography

* This assumes we’re dealing with code snippets. In the general case, it can also break when there are inline elements that force a larger line height, such as images or inline content with a larger font-size.

6 User Experience

* In usability, an affordance is a property of a control that visibly hints how we can interact with it. For example, a button’s 3D appearance hints that it can be pushed, and a doorknob’s appearance that it can be pulled or turned. For more info, check out en.wikipedia.org/wiki/Affordance. There is some debate among usability professionals as to whether mouse cursor changes are an affordance or visual feedback.

* From the CSS 2.1 specification: “[A replaced element is] an element whose content is outside the scope of the CSS formatting model, such as an image, embedded document, or applet.” Replaced elements cannot have generated content applied to them, though some browsers allow it.

7 Structure & Layout

* In CSS spec ...