HTML principle: Put the content in HTML and do not rely on CSS

Content should be placed in HTML instead of CSS. This is an important principle of HTML. The following example clearly demonstrates this problem:

When CSS is available, the page content is normal.

When a page is unavailable and can only be accessed through https, CSS becomes invalid because the CSS of the page is http. At this time, the page content is lost, because the table on this page depends on the CSS image.

 

HTML compliant with W3C standards is like this: text is used for content, text-indent:-3000px is used to offset the text to invisible places, and background image is used for replacement, so that when CSS is unavailable, the text is displayed. HTML and CSS code compliant with W3C standards download: http://files.cnblogs.com/sink_cup/report.7z

When CSS is available, the text offset shows the background image. The effect is as follows:

When CSS is disabled, the text is displayed. The effect is as follows: