The backdrop-filter property provides for effects like blurring or color shifting the area behind an element, which can then be seen through that element by adjusting the element's transparency/opacity.
The CSS repeating-linear-gradient function creates an <image> consisting of repeating gradients. It works similarly to the basic linear gradients as described by linear-gradient(), and takes the same arguments. However, it automatically repeats the color stops infinitely in both directions. The color stops' positions shift by multiples of the length of a basic linear gradient (the difference between the last color stops' position and the first).
The <transform-function> CSS data type denotes a function applied to an element's representation in order to modify it. Usually such transform may be expressed by matrices and the resulting images can be determined using matrix multiplication on each point.