The cascade is a fundamental feature of CSS. It is an algorithm defining how to combine properties values originating from different sources. It lies at the core of CSS as stressed by its name: Cascading Style Sheets.
A CSSlayout mode, sometimes abbreviated as layout, is an algorithm determining the position and the size of boxes based on the way they interact with their sibling and ancestor boxes. There are several of them:
The resolved value of a CSS property is the value returned by getComputedStyle(). For most properties, it is the computed value, but for a few legacy properties (including width and height), it is instead the used value. See the specification link below for more per-property details.
CSS offers a number of powerful features that can be tricky to use, or have a number of parameters, so that it's helpful to be able to visualize them while you work on them. This page offers links to a number of useful tools that will help you build the CSS to style your content using these features.
An at-rule is a CSS statement beginning with an at sign, '@' (U+0040 COMMERCIAL AT), followed by an identifier and includes everything up to the next semi-colon, ';' (U+003B SEMICOLON), or the next CSS block, whichever comes first.
When a URL points at a specific piece of a document, it can be difficult to ascertain. Find out how you can use some simple CSS to draw attention to the target of a URL and improve the user's experience.
CSS3 is the latest evolution of the Cascading Style Sheets language and aims at extending CSS2.1. It brings a lot of long-awaited novelties, like rounded corners, shadows, gradients, transitions or animations, as well as new layouts like multi-columns, flexible box or grid layouts. Experimental parts are vendor-prefixed and should either be avoided in production environments, or used with extreme caution as both their syntax and semantics can change in the future.
Set the direction CSS property to match the direction of the text: rtl for languages written from right-to-left (like Hebrew or Arabic) text and ltr for other scripts. This is typically done as part of the document (e.g., using the dir attribute in HTML) rather than through direct use of CSS.