Errata

(covered in later in this book).
change to:
(covered later in this book)

Wrong:
@media (min-resolution: 960dpi) {...}

Correct (for consistency with the previous line):
@media (min-resolution: 96dpi) {...}

Concerning the following sentence:

"For example, say you’re drafting a document that discusses ways of handling plutonium."

The examples involving the text with plutonium started much earlier in this chapter (p. 30). It seems that content rearrangement happened along the way, and suddenly, the example about the plutonium text is being introduced as if it was just mentioned.

Note from the Author or Editor:
Agreed. Changes submitted via Atlas.

The paragraph begins with "Again, that's in langauges ..."

"langauges" should of course be "languages"

"... to be absolute URLS, ..." --> "... to be absolute URLs, ..." (lowercase "s" in URLs)

The note begins "Styled visited links enables visitors to know ..."

Instead of "enables", it should be "enable": "Styled visited links enable visitors to know ... "

(Unless, of course, one had an alternative wording in mind, like "The feature "styled visited links" enables ...", but then in my opinion that should be articulated explicitly.)

The paragraph contains

'[...] which are not checked with input[type="checkbox]:not(:checked).'

The closing double quote after 'checkbox' is missing:

input[type="checkbox"]:not(:checked)

Note from the Author or Editor:
Correction made via Atlas.

This is just a tiny stylistic improvement. It says:

textarea:read-only { opacity: 0.75;}

The space that follows the opening brace is inconsistent with how other rules are formatted. Hence it should be

textarea:read-only {opacity: 0.75;}

(without the space)

Note from the Author or Editor:
Correction made via Atlas.

Another tiny stylistic remark. The "!important" keyword is split across pages 102/103. The exclamation mark "!" appears as the last character on page 102, while "important" is on the next page. Perhaps unicode U+2060 (word joiner) can be used to avoid this?

Note from the Author or Editor:
Agreed. Please do whatever one does to prevent this!

It states that inherit is covered in the previous chapter; it's not, it's covered in the next chapter.

Note from the Author or Editor:
Change the sentence:

Another way to get the same result is to use the value `inherit`, covered in the previous chapter.

to:

Another way to get the same result is to use the value `inherit`, covered in the next chapter.

... is matched by four of the rules - :link, Lfocus, :hover and :active ...

Lfocus shoud be :focus

Note from the Author or Editor:
This is definitely a typo.

Lfocus should be changed to :fous

"If a display's resolution is set to 1024 pixels wide by 768 pixels tall, its screen size is exactly 10 2/3 inches wide by 8 inches tall, and the screen it is filled entirely by the display pixels, then each pixel will be 1/96 of an inch wide and tall."

I think the "it" in "... and the screen *it* is filled ..." is superfluous.

"The permitted operators are [...] multiplcation [...]."

This should of course read "multiplication".

The text reads:

"If you declare three values, the rules are the same as for four, except the last offset is
set to be zero (no offset). Thus right 20px top is the same as right 20px top 0 ."

Instead of saying "[...], except the last offset [...]" I would suggest using "[...], except the missing offset [...]" as using a value structured thusly: right top 20px; is perfectly valid based on the position values rules specified in the standard. I tested my value in both Firefox and Chrome with success.

Note from the Author or Editor:
Corrections made via Atlas.

The paragraph above "How Weights Work" (starting with "What's really happening") includes an unfortunate hyphenation of "TimesBold":

[...] Time-
sBold [...]

Note from the Author or Editor:
Agreed, but that’s outside my scope of power. Whatever one does to prevent such things, please do!

The paragraph beginning with "As you can see" has a phrase reading "[...] and then evaluate to the next-heaviest face, [...]". I believe that should have been "next-heavier".

Note from the Author or Editor:
Sure, why not. Correction made via Atlas.

I don't think you mean "Figure 5-12"; I think you mean Figure 5-15.

The sentence inside the figure lacks a word:

Actual: "If there one thing"
Expected: "If there is one thing"

Note from the Author or Editor:
Corrected figure submitted 2019-06-17.

The sentence starting with "Much as with ..." uses inconsistent formatting:

"font-weight descriptor": "font-weight" is formatted monospace
"font-stretch descriptor": "font-stretch" is not formatted monospace. It should be monospace, too.

Typo in "Similarly, a font family that lacks an italic face an have one [..]"

"an have one" should be "can have one"

There's a typo in "You can block it for the whole document with html (font-synthesis: none;}"

The opening parenthesis "(" should be an opening brace "{".

Note from the Author or Editor:
Corrected via Atlas.

The first CSS comment in the four declarations at the end of the page reads "/*no problem here */", where, for stylistic and consistency reasons, there should be a space between the opening comment tag "/*" and "no".

Note from the Author or Editor:
I mean, yes, that would be consistent, although what was presented is not invalid—but I updated it in Atlas anyway.

The last word on the line beginning with "The distance between lines" is lowercase, it should be uppercase (since it starts a new sentence).
Actual: 'note that "height" here is with respect to ...'
Expected: 'Note that "height" ...'

Note from the Author or Editor:
Corrected via Atlas.

The figure contains "some text which is not tall", whereas the related markup reads "some text that is not tall".

Note from the Author or Editor:
Change the code block to use the text “some text which is not tall”.

There is an unnecessary line break in the markup, the word "beneath" stands by itself in a new line, followed by a line break and "it as well.</p>" (cf. figure 6-31)

Note from the Author or Editor:
I would say, bring the text "it as well.</p>" up to the previous line in the text block.

Change "first" with "last".

Sentence starts with:
The first of these attribute selectors ...

Though based on examples from Table 15-1 this should be:
The last of these attribute selectors...

Note from the Author or Editor:
The reader is correct.

Sentence "If there are two, the third is copied form the first..." should read "If there are two, the third is copied from the first..."

Sentence "There, we can see an element that's bee floated to the left..." should read "There, we can see an element that's been floated to the left..."

"the image is attached ot the local" should read "the image is attached to the local"

Also, should the next word in the sentence be "content" rather than "context"?

2nd sentence should have "that" instead of "than".

So "This means than orange, green and blue will be evenly distributed between the explicitly defined positions to either side." should read "This means that orange, green and blue will be evenly distributed between the explicitly defined positions to either side."

in other words, if an element has an explicitly
should be:
In other words, if an element has an explicitly
("I" needs to be capitalized.)

In the 3rd paragraph,
“In cases…minxmax() can be quite useful.”
"minxmax()" should be "minmax()".

The index entry for "box-shadow" only points to pages 886 and 887. The main section for those starts on page 485, which, I think, the index should (also, primarily) refer to.

Note from the Author or Editor:
The index is wrong. I don’t know how that is fixed, but it should be!