19. The computer-readable storage medium of claim 16 , being further encoded with instructions that, when executed, cause the at least one processor of the computing device to output, for display, a graphical indication of the rendered respective portion of the content.
16. A computer-readable storage medium encoded with instructions that, when executed, cause at least one processor of a computing device to: detect a change to a power mode of the computing device; responsive to detecting the change to the power mode, process, from among a set of elements within a page of content that each specify a respective portion of the content in accordance with a markup language, the page of content to identify one or more elements of the set of elements that each have at least one respective attribute designated to be modified in response to the change to the power mode; modify, based on the change to the power mode, at least a portion of the at least one respective attribute of each of the identified one or more elements to associate the respective portion of the content specified by each of the identified one or more elements with a set of presentation properties; and render, for display in accordance with the set of presentation properties, the respective portion of the content specified by each of the identified one or more elements.