1. A method comprising: detecting, by a computing device, a change to a power mode of the computing device; responsive to detecting the change to the power mode, processing, by the computing device and 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; modifying, by the computing device and 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 rendering, by the computing device and 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.
7. The method of claim 1 , further comprising: responsive to determining that an activity timer associated with the computing device has lapsed, transitioning, by the computing device, to a sleep mode associated with the computing device, wherein the change to the power mode is detected in response to the transition to the sleep mode.