Common things to note about DIV CSS_html/css_WEB-ITnose

When we use CSS DIV to reconstruct our html pages, we usually find that some are one of the commonly used terms in website standards (or "WEB standards"), usually for explanation The difference from the table positioning method in the HTML web design language is that in the XHTML website design standards, table positioning technology is no longer used, but CSS div is used to achieve various positioning. It's easy to make some mistakes when using DIV CSS coding. This article lists some common mistakes:

1. Check whether there are spelling errors in HTML elements (such as:

,
) and attributes (such as: class=""), and whether you forget to end Tags (such as:
)
Since Xhtml has strict syntax, if browsers such as Firefox find syntax errors in Xhtml, the page will not be displayed normally. Even experienced users often get the nesting of divs wrong. You can use Dreamweaver's verification function to check for errors.

　2. Check whether the CSS is correct

　Check whether there are any spelling errors, whether you forgot the ending }, etc. You can use CleanCSS to check CSS for spelling errors. CleanCSS is a tool to reduce weight for CSS, but it can also check for spelling errors.

　3. Determine where the error occurred

If the error affects the overall layout, you can delete the div blocks one by one until the display returns to normal after deleting a certain div block, then you can determine where the error occurred. Location.

4. Use the border attribute to determine the layout characteristics of the error element

Using the float attribute for layout may cause errors if you are not careful. At this time, add the border attribute to the element to determine the element boundary, and the cause of the error will be revealed.

5. The parent element of a float element cannot specify the clear attribute

If you use the clear attribute on the parent element of a float element under MacIE, the layout of the surrounding float elements will be confused. This is a famous bug of MacIE. If you don't know it, you will take detours.

6. Float elements must specify the width attribute

Many browsers have bugs when displaying float elements without specified width. So regardless of the content of the float element, the width attribute must be specified for it. In addition, try to use em instead of px as the unit when specifying elements.

7. Float elements cannot specify attributes such as margin and padding

IE has a bug when displaying float elements with margin and padding specified. Therefore, do not specify margin and padding attributes on float elements (you can nest a div inside the float element to set margin and padding). You can also use hacks to specify special values ​​for IE.

8. The sum of the widths of float elements must be less than 100%

If the sum of the widths of float elements is exactly 100%, some ancient browsers will not display properly. Therefore, please ensure that the sum of the widths is less than 99%.

9. Have you reset the default style?

Different browsers have different interpretations of certain attributes such as margin, padding, etc. Therefore, it is best to set all margin and padding to 0, list style to none, etc. before development.

　10. Did you forget to write the DTD?

If the display results of different browsers are still different no matter how you adjust it, then you can check whether you forgot to write the following line of DTD at the beginning of the page: