1. selector + Declaration: Attribute + value eg: h1 {color: red; font-size: 14px;} color: p {color: # ff0000;} p {color: # f00;} p {color: rgb (100%, 0, 0);} p {color: rgb (0%, 0%,);} Word time: p {font-family: "sans serif";} 2. selector group h1, h2, h3 {color: green;} 3. inherited body {font-family: Verdana, sans-serif ;} if the browser does not support inheritance: body {font-family: Verdana, sans-serif;} p, td, ul {font-family: Verdana, sans-serif;}, get rid of inheritance: body {font-family: Verdana, sans-serif;} p {font-family: Times, "Times New Roman", Serif;} 4. derived selector li strong {font-style: italic; font-weight: normal ;} this format <li> <strong> strong in li </strong> </li> 5. id selector # red {color: red ;}# green {color: green;} use: <p id = "red"> red </p> <p id = "green"> green </p> id is unique on a page. Do you want to know why? Haha !!! Id selector and derived selector: apply only to p # sidebar p {font-style: italic; text-align: right; margin-top: 0.5em;} Whose id is in sidebar ;} independent selector: # sidebar {border: 1px dotted #000; padding: 10px;} 6. class selector. center {text-align: center} usage: