attribute attribute, spacepval, dash-val, value Attribute Select based on attribute Dash-val Select hyphen separated instances of a value Space-val Select space separated instances of a value Value Select based on value Select based on attributes or list of attributes or value of an attribute. class .big {color:blue } Type selectors target every instance of an element, class selectors select any HTML element that has a class attribute. descendant div > em, "p em" Child div > em { color: blue; } Descendants p em {color: blue; } following h2 + h3 {margin: -1em; } Select all occurrences of h3 which are places after h2. id #navigation { width: 12em; color: #333; }#navigation Select any HTML element that has an ID attribute, regardless of their position in the document tree preceding p ~ ul Selects every UL element that are preceded by a P element.

psuedoclasses active, first-child, focus, hover, lang, link, visited Active First-child Focus Hover Lang Link Visited psuedoelements after, before, first-letter, first-line After Before First-letter First-line type em {color: blue; } Type selectors will select any HTML element on a page that matches the selector, regardless of their position in the document tree. For example: em {color: blue; } This rule will select any <em> element on the page and color it blue. universal * {color: blue; } Universal selector. usage Affect-other The button and the light problem Class and type Combining class and type selectors Conflicts Handled badly. Zero permitted. Id or class When to use id, when to use class. Inheritence How inheritance works, why and when it doesn't. Less class Think before you class Mutiple classes How to specify multiple CSS classes