The progress() CSS function returns a ratio for the relative position of one value between two other values, clamped between 0 and 1. You can use it to interpolate a value for other calculations.

The sibling-count() and sibling-index() CSS functions return integers that are useful to style elements based on their positions among siblings or on the number of siblings, for example as part of a calc() expression.

The field-sizing CSS property allows form controls such as <textarea> to be sized based on their content.

The @scope CSS at-rule sets the scope for a group of rules.

The font-family: math CSS declaration uses the browser default font face for displaying mathematical expressions.

The content-visibility CSS property delays rendering an element, including layout and painting, until it is needed.

The abs() and sign() CSS functions compute the absolute value or the sign of the input.

The from keyword for color functions (color(), hsl(), oklch(), etc.) creates a new color based on a given color by modifying the values of the input color. Also known as relative color syntax (RCS).

The backdrop-filter CSS property applies graphical effects such as blurring or color shifting to the area behind an element.

The @starting-style CSS at-rule sets the starting values for properties that are transitioning when the target element's style is first updated.

The / notation in content CSS property values adds alternative text to generated content. For example, the content: url('upvote-icon.svg') / 'Upvote' declaration adds accessible 'Upvote' text to the SVG icon. Also known as alternate text.

The round(), mod(), and rem() CSS functions compute rounded values and the remainder after division.

The light-dark() CSS function accepts two colors and uses one depending on the current color scheme.

The writing-mode CSS property orients form elements (such as radio buttons, progress bars, or select menus) vertically when the writing mode is vertical-lr or vertical-rl. The direction CSS property sets whether inputs flow from top to bottom or bottom to top.

The paint-order CSS property sets the z-order of strokes, fills, and (in SVG content) markers. For example, paint-order: markers stroke fill; draws the markers, then stroke on top of markers, then fill on top of both markers and stroke.