CSS you have never experienced--[Beef Brisket News Release System]_html/css_WEB-ITnose

1. Background:

With the development of the Internet, the requirements for personalization of web pages are also constantly increasing. HTML, HyperTextMarkupLanguage, Hypertext Markup Language, is originally an explanatory text, but users need more tags and attributes, and then they keep adding HTML tags and attributes, causing confusion in web page content and style, and making it difficult to maintain. Therefore, it was at this time that CSS came out, realizing the separation of web page content and style, greatly improving the efficiency of writing and modifying pages!

2. What is CSS?

CSS (CasCading Style Sheets), cascading style sheets, means that styles and content are stacked one on top of the other like hamburgers, sandwiched~

3. What is a CSS selector? ?

To use CSS to achieve one-to-one (ID), one-to-many (class), or many-to-one (tag) control of elements in an HTML page, you need to use CSS selector. The ID selector is like an ID card, one for each person, and is more targeted; the class selector is very commonly used in easyUI. For example, if the class in the control in easyUI is set to easyUI-datagrid, the table style can be well unified. Personally, I feel that if you are building a large system with many subsystems, the class selector has a good ability to unify the world; the label selector, whether it is your head (head) or your arms and legs (body), is within the control range of the label~

Types and priorities of CSS selectors:

ID selector>class selector>HTML tag selector

Let’s use a small DEMO to verify the priority of the selector:

1. First create a CSS style sheet on the client, the code is as follows,

/**创建人：王美*创建时间：2015年2月23日16:14:53*//*css样式*//*标签选择器*/body {    color:#f0f;/*粉红色*/}/*类选择器*/.menu {    color:#f00; /*红色*/}.title {  /*新闻标题样式*/   color:#00f; /*蓝色*/}/*ID选择器*/#special {    font-weight:bold ;/*粗体*/    color:#0f0;/*绿色*/}

2. Create an HTML page:

<!--		创建人：王美		创建时间：2015-02-23 15:56:31--><meta http-equiv="Content-Type" content="text/html; charset=utf-8">    <title>css测试</title>    <link href="css/StyleSheet.css" rel="stylesheet">    <span id="special" class="menu">栏目四</span>    <span class="menu">栏目五</span>    <span class="menu">栏目六</span>    <span class="title">这是<span> 一</span>条新闻标题</span>    434434343434346464

3. Display the result after running:

4. To sum up, the ID of
column four

is special, the class is menu, the color of special in css is green, the font color of menu is red, and column four is green, proving the priority ID selector> class selector; in the body HTML tag, the one with class is red, and the default bodyHTML tag format is pink, proving the priority class selector> HTML tag selector

4. Summary

Abstraction drives programming progress.