The first part
1. Class names are case-sensitive:. Special and. Special are different.
2.: Focus is centered in a place by clicking or jumping on a grid
3,:: Selection no single colon, selected text "
But not supported in IE8 and Firefox,
Use à::-moz-selection{}
】
4: Not () only one ": Not (): Not ()" In a selector, cannot use the derived selector ": not (Div p)"
5, ^ with what beginning, $ with what end, * contains what
6, p* refers to elements inside the P element
Part II
1. Rgba is not supported in IE8 and earlier versions, so you can use:
Color:rgb (155,100,50);//Support IE8
Color:rgba (155,100,50,.5);
2, Keyword:xx-small (9)/x-small (/small)/medium (/large)/x-large (32)
3. When the bottom margin of an element is used with the top margin of the next element, the margin is not added, but the largest margin is used
4, Border-radius: If you want to set into an oval, then 40px/20px
Fourth part
Response type:
1, <title> above plus <meta name= "viewport" content= "Width=device-width"/>
2, IE8 and earlier versions do not support media queries
So add:
<!--[If LTE IE 8]>
<script src= "Js/respond.min.js"/>
<! [endif]-->
Positioning:
1. Do not set float and position:absolute and fixed in one element at the same time
Memorandum of the CSS3 scroll