Documentation_html/css_WEB-ITnose with a little bit of div css page layout

1. When using display:none to hide an element, the original position of the element will not be retained, but using visibility:hidden will not.

2. Using margin:auto can make a The element is displayed in the center

3. When the width of the element exceeds the width of the browser, a horizontal scroll bar will appear in the browser. At this time, max-width can be used instead of width. max-width can adapt to the browser width and supports IE7 and Other mainstream browsers

4. When calculating the width of the element, the length of the border and the padding will also be calculated. This will be more troublesome. Use the following code to solve this problem. Problem

*{   -webkit-box-sizing:border-box;       -moz-box-sizing:border-box;                box-sizing:border-box;   }

But this only supports IE8 and other mainstream browsers

5. Several values ​​of the postion attribute

Name

Function

static

Default value, that is, not positioned

relative

Used together with the top, left, bottom, and right attributes to deviate the element from its normal position, other elements will not fill the gap left by it

fixed

名称	作用
static	默热值，即未被positioned
relative	配合top,left,bottom,right属性一起使用，使元素偏离正常位置，其他元素不会来填补它离开所剩下的空缺
fixed	也配合top,left,bottom,right属性一起使用，使元素相对于当前浏览器视窗来定位，改变浏览器视窗的大小， 不会改变元素相对于视窗的位置
absolute	该属性与fixed属性类似，但它不是相对于视窗，而是相对于离它最近的被positioned的属性（指position值不是static的元素）

is also used together with the top, left, bottom, and right attributes to position the element relative to the current browser window and change the size of the browser window. ,

Does not change the position of the element relative to the viewport

absolute

This attribute is similar to the fixed attribute, but it Not relative to the view window, but relative to the nearest positioned attribute (referring to the element whose position value is not static)