1. A server-side for a headend, comprising: one or more processors; one or more computer storage media storing computer-executable instructions that, when executed, cause one or more processors to: compute style rules for a plurality of elements of video content in an original markup language to define pseudo-classes which preserve a dynamic layout, presentation, rendering, and user interface interaction of a plurality of elements of the content; parse the video content in an original markup language into a Document Object Model (DOM) tree based on the style rules and the pseudo-classes that includes layout, rendering, user interface (UI) interaction, and dynamic aspects of the video content; and transcode the DOM tree via a selected client-specific routine that is specific to a particular client and a markup-specific routine that is specific to a content model into a serialized byte-stream of the video content, the serialized byte-stream of video content including the style rules and a list of the pseudo-classes to preserve preserving the layout, rendering, UI interaction, and dynamic aspects of the video content of the video content on the predetermined client in the original markup language; and a network interface coupled to the one or more processors to communicate the serialized byte-stream.