When a paragraph is split over two pages in paged media, the widowsCSS property defines the minimum number of lines that must be left at the top of the second page. In typography, a widow is the last line of a paragraph appearing alone at the top of a new page. Setting the widows property allows the prevention of single-line widows.
The will-changeCSS property provides a way for authors to hint browsers about the kind of changes to be expected on an element, so that the browser can set up appropriate optimizations ahead of time before the element is actually changed. These kind of optimizations can increase the responsiveness of a page by doing potentially expensive work ahead of time before they are actually required.
The border-collapse CSS property determines whether a table's borders are separated or collapsed. In the separated model, adjacent cells each have their own distinct borders. In the collapsed model, adjacent table cells share borders.
CSS Grid layout contains design features targeted at web application developers. The CSS grid can be used to achieve many different layouts. It excels at dividing a page into major regions, or defining the relationship in terms of size, position, and layer, between parts of a control built from HTML primitives.
The font-variant-ligatures CSS property controls which ligatures and contextual forms are used in textual content of the elements it applies to. This leads to more harmonized forms in the resulting text.
Historically, the CSS :visited selector has been a way for sites to query the user's history, by using getComputedStyle() or other techniques to walk through the user's history to figure out what sites the user has visited. This can be done quickly, and makes it possible not only to determine where the user has been on the web, but can also be used to guess a lot of information about a user's identity.
The :-moz-lwtheme-brighttextpseudo-class matches in chrome documents when :-moz-lwtheme is true and a lightweight theme with a bright text color is selected.