Shoot to kill; CSS selector intent — CSS Wizardry—CSS, Web Standards, Typography, and Grids by Harry Roberts

One type of CSS in particular makes me cringe every time I see it; poor selector intent. Poor selector intent means carpet bombed selectors whose key selector has way too broad a reach; a selector like .header ul{} as opposed to one like .main-nav{}, .widget h2{} instead of .widget-title, article > p:first-child{} as opposed to .intro{}. Selectors whose intent isn't specific enough.  [...]

http://csswizardry.com/2012/07/shoot-to-kill-css-selector-intent/