CSS is designed primarily to enable the separation of document content (written in HTML or a similar markup language) from document presentation, including elements such as the layout, colors, and fonts.[2] This separation can improve content accessibility, provide more flexibility and control in the specification of presentation characteristics, enable multiple pages to share formatting, and reduce complexity and repetition in the structural content (such as by allowing for tableless web design). CSS can also allow the same markup page to be presented in different styles for different rendering methods, such as on-screen, in print, by voice (when read out by a speech-based browser or screen reader) and on Braille-based, tactile devices. It can also be used to allow the web page to display differently depending on the screen size or device on which it is being viewed. While the author of a document typically links that document to a CSS file, readers can use a different style sheet, perhaps one on their own computer, to override the one the author has specified.
A study of Charité Hospital in Berlin by Lorenzo et al., published in The European Heart Journal, showed adding milk to tea causes the casein to bind to the molecules in tea that cause the arteries to relax, especially a catechin molecule called EGCG, although a more recent study by Reddy et al. (2005) suggests the addition of milk to tea does not alter the antioxidant activity in vivo,[29] and the cardiovascular effect remains controversial.[30][31] A study published in the journal Free Radical Biology and Medicine found that consuming 200 mL of whole milk (vs. water control beverage) abolished the 6.1% increase in plasma reducing and chain-breaking antioxidant potential that resulted from consuming 200 g of blueberries, and reduced the peak plasma concentrations of caffeic and ferulic acids, "as well as the overall absorption (AUC) of caffeic acid."[32] The authors did not specifically associate this with the milk's casein content, however. Reviewing previous studies on the impact of milk on absorption of polyphenols, the authors say, "It is a matter of fact that the discrepancy of the results in humans is remarkable, with half the reports suggesting a lack of effect and the other half suggesting an inhibitory effect of milk."[32]