英文css教程:Introduction CSS

所属分类: 网页制作 / CSS 阅读数: 1100
收藏 0 赞 0 分享

CSS actually means Cascading Style Sheets. Styles are used to define how HTML elements are displayed. They are usually stored in STYLE SHEETS and were first seen included in HTML 4.0, with the purpose of solving a problem that appeared. These are bas
Few people really know what CSS really is. That is why we need to discuss this in the following set of tutorials that we will hand out as fast as possible. We will cover basic, medium and advanced CSS in a set of CSS Tutorials that you will surely enjoy utilizing. Remember that you do need basic knowledge about HTML/XHTML in order to work with CSS. This is highly important and if you do not know HTML then you should first focus on that and then on learning from CSS Tutorials.
What is CSS?
CSS actually means Cascading Style Sheets. Styles are used to define how HTML elements are displayed. They are usually stored in STYLE SHEETS and were first seen included in HTML 4.0, with the purpose of solving a problem that appeared. These are basically external, in the sense that they are not actually included in your HTML coding. External Style Sheets are used in order to SAVE YOU WORK. CSS files are utilized to store them and you need to understand that we have the advantage of using multiple style definitions that will eventually cascade in just one.
Why did CSS appear?
As already mentioned, CSS was developed in order to solve a problem with HTML. Regular HTML tags have been built to define the actual content of one document. We were faced with simple HTML tags like <h1>, <table>, <p> etc. There was no need to use formatting tags because the actual document was taken care of by your browser. As time passed we were faced with browsers adding HTML attributes and tags. This complicated everything and eventually led to difficulty in creating web sites. The statement is extremely true when talking about sites that showed a separation between the actual presentation and the content. As a result of this problem STYLES were added to HTML 4.0 by W3C. Now we can clearly notice that all of the main web browsers out there support CSS.
Time Saved through CSS
Style sheets will save you time because they will define how some or all HTML elements are displayed. The most basic examples of HTML elements’ appearance that can be controlled stands in the color tag and font tag, which appeared in HTML 3.2. In most cases the web master/designer/admin will store all styles in .css files. These are basically the External Style Sheets mentioned above. The actual time saving comes from the fact that you will just need to edit on .css file instead of many of your web pages. For instance, let us think that you will want to change the color of the links on all of your html files. You would normally do this by doing modifications on every single file. Through the use of CSS you will just need to modify ONE FILE. You will be able to define one style for each web element that you want. Then the style can be applied to as many html files as needed. A global change is done in just one file.
What is the deal with Multiple Styles Cascading in One?
We did notice that there is a little problem with understanding this concept so we do need to add it to our CSS tutorial introduction. All style sheets will allow you to define info about style and the info can be given in various ways. You can specify styles in External Style Sheets, in an HTML element inside the web page or in one HTML element. There is a posibility to have more than one style defined for 1 HTML element. In this case we are faced with order cascading. Every style present will be read by the browser and cascade into one new styles sheet, which we can consider virtual. This is done by obeying a simple list of order defined by priority. The way you see an element will be given by the element with the highest priority. The order is:
1.Inline Style (defined inside the HTML element)
2.Internal Style Sheet (defined inside a tag)
3.External Style Sheet
4.Browser default settings.
更多精彩内容其他人还在看

CSS样式分离之再分离达到精简与重用

无论是CSS的分离还是js的分离,其主要作用之一就是精简与重用,CSS本身就代表着精简与重用,CSS样式分离,我一般指的是“以单独的CSS文件将CSS样式分离出来”,此处的重用多针对不同页面的重用,就是说,一个样式文件,可以多个页面使用,这对于一些公共样式的重构是很有
收藏 0 赞 0 分享

CSS属性behavior的语法使用说明

在进行CSS网页布局的时候,我们经遇到刷新要保留表单里内容的时候,习惯的做法使用cookie,但是那样做实在是很麻烦,css中的behavior就为我们很好的解决了这个问题。今天jb51.net就向大家介绍CSS属性behavior的语法
收藏 0 赞 0 分享

网页制作中的水平居中和垂直居中解决方法集合

 在定义网页的CSS样式的时候,我们或许并不怎么用到垂直居中。
收藏 0 赞 0 分享

最常见IE的Bug及其fix修复方法

Internet Explorer – Web程序员的毒药。在IE上开发时间中有超过60%的时间是花在和IE的bug进行搏斗,让你的开发生产率严重下降。下面是一个教程,告诉你9个IE上最常见的BUG以及如何解决它们。
收藏 0 赞 0 分享

CSS常用浏览器兼容调整小结

用CSS+DIV来写网站代码的好处显而易见,这里不多说了,但由于不同浏览器对CSS的解释不统一,造成不同浏览器下页面错位的现象十分常见……
收藏 0 赞 0 分享

css firefox火狐浏览器下的兼容性问题

css firefox火狐浏览器下的兼容性问题
收藏 0 赞 0 分享

DIV+CSS 浏览器兼容性小结

在网站设计的时候,应该注意css样式兼容不同浏览器问题,特别是对完全使用DIV CSS设计的网,就应该更注意IE6 IE7 FF对CSS样式的兼容,不然,你的网乱可能出去不想出现的效果!
收藏 0 赞 0 分享

div+css 布局常识 8问

CSSer与其他IT职位一样,在找工作的时候,都会面临着面试官提出的问题,或者给出的试卷。今天jb51.net收集了常见的8条面试题目,希望对您有所帮助。
收藏 0 赞 0 分享

CSS用四种方式实现布局

CSS用四种方式实现布局
收藏 0 赞 0 分享

css 解决表格边框不显示的问题

在 IE6 中,当表格单元格中的数据为空时,边框是不显示的,在IE8中是会显示的,怎样解决这个不兼容的问题呢。
收藏 0 赞 0 分享
查看更多