CSS Rendering Engine (1/2)

...continued from HTML Rendering Engine

CSS parsing is more strict ( but bear in mind CSS is not truly a "language", it is simply a set of markup rules.)

CSS Parsing

The CSS parse tree is converted into the CSSOM.

CSSOM

Speculative parsing happens in a separate thread.

Order of Parsing

The DOM and the CSSOM are combined to form the Render Tree. (The Render Tree is constructed asynchronously).

Render Tree Construction

Render Tree and DOM tree are similar, but not 1:1.

Render and DOM trees

Continued in CSS Rendering Engine. 2/2