Calmer surfaces, clearer buttons

Backgrounds, borders and menus are now near-neutral grey, so the blue you see marks something: the action to take, the item you've selected, or a link. Buttons follow one order: a solid fill for the main action, a soft grey fill or a thin outline for a secondary action, and no fill at all until you hover over a quiet one. Nothing uses a shadow to stand out any more - shadows are saved for things that float above the page, like menus and popups.