Being Aware of Initial Values in Your CSS

Technically speaking, the initial value of any given property needs to be declared only if that value is overriding a previously-defined value that’s not the initial value. But initial values are often present even when they’re not necessary.
For example, suppose I have a block-level element that I want to take up the full width of its parent. I want it to sit on its own “line”, so to speak, in the layout, so I add the following CSS:
If you’ve been writing CSS for some time, then you’ve certainly done something similar to the following, and likely multiple times in a single stylesheet:
In most cases, you should not use a leading or trailing space in an HTML attribute value. For example, if you add a leading or trailing space to an ID attribute, you wouldn’t be able to hook into that value in CSS using the ID selector (not that you use IDs as selectors, right?):
As you probably know, there are a number of HTML attributes that are considered global because they can be applied to any HTML element. Common examples include
There are two things here that you’re probably already aware of. First, HTML includes an
This just in: Web developers are easily swayed by tentacled sea creatures. But wait, I’m getting ahead of myself. I’ll get back to that in a moment.
One thing that’s common in development blog posts and documentation is the use of HTML’s
A common UI pattern for a range slider is to allow the user to move the slider and display the value of it somewhere on the page, changing the displayed value as the user moves the slider.
Back in 2008, Paul Irish posted a modest list of RSS feeds for front-end developers to follow. Since that original post, he’s updated the list multiple times, and his list is now on GitHub growing to over 200 feeds.