Detailed discussion on the use of CSS style sheets: link/embed_CSS/HTML

In Ajie’s w3cn, he said:

Quoted content
In the past, we usually used style sheets in two ways:
Page inline method: that is, writing the style sheet directly in the head area of ​​the page code. Similar to this:

External calling method: Write the style sheet in a separate .css file, and then call it with code similar to the following in the head area of ​​the page.

In a design that complies with web standards , we use the external calling method, and the benefits are self-evident. You can change the style of the page without modifying the page, only modifying the .css file. If all pages call the same style sheet file, then changing one style sheet file can change the styles of all files.

It can be seen that Ajie highly recommends using . To add to Ajie's words, the advantage of using is not only that it is convenient to modify the style sheet, but also that it will speed up the user's browsing speed. The first time a user opens a page linked to a style sheet, the style sheet will be automatically downloaded to the local cache. When the user opens another page, and if this page is also linked to the same style sheet, the relevant files will be read from the cache, which will speed up browsing.

But I have also encountered this situation: Sometimes when the network is not smooth, after the page is opened, the linked style sheet does not load successfully. The consequences of this situation are not only that the color, size and other styles of the text on the page cannot be displayed, but what is even more troublesome is that the layout of the entire page may be messed up!

For example, once when I opened Macromedia.com, the company network was not smooth, maybe because there were many people in the bt bar. . . The result page appears without a style sheet at all, and the familiar layout is no longer visible. All content is arranged from top to bottom, just like browsing a website on a mobile phone. Although all the content can still be seen, I had to spend some time getting familiar with this new layout, and there was a feeling of unsmoothness when browsing.

When I was making the homepage of Kingsoft Online (the previous version is no longer visible), I embedded all the styles into the area of ​​the page. The homepage is the most visited page of a website and must ensure high reliability. Moreover, only the homepage style sheet is embedded, and other pages still use , so it will not increase too much workload when modifying the style.

When I was working on amaoagou’s homepage over the weekend, I further planned the style: I embedded layout-related styles such as #head and #left into the inside of the page, and other styles were linked.

To summarize:

* Method 1: The homepage is completely embedded, and other pages are linked. Advantages: This ensures that the homepage can still be displayed correctly even if the network condition is poor. Disadvantages: When modifying the style, you need to modify the external style sheet and the embedded style sheet on the homepage.
* Method 2: Write the styles responsible for layout separately from other styles. The homepage embeds the layout style and links to other styles; other pages use links to both sets of styles. Advantages: When modifying the style, the workload is smaller than the first method. When the network condition is not good, the appearance of the homepage cannot be completely guaranteed, but at least the layout will not be messy.
* If the page produced does not meet the standards, such as a small topic on the company's products, the leader requires it to be produced with a table to ensure the speed of the topic online. Styles used on every page: links. For a style that will only be used on this one page, but will be used many times: embed . For styles that will only be used on this page and only once: embed the or simply write style="..." directly.