1. Check whether there are spelling errors in HTML elements and whether the closing tag is forgotten.
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 for spelling errors, forgotten } at the end, 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, and you can determine where the error occurred.
4. Use the border attribute to determine the layout characteristics of the error element
Using float attribute layout can 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.
Under MacIE, if you use the clear attribute on the parent element of a float element, the layout of the surrounding float elements will be chaotic. This is a famous bug of MacIE. If you don't know it, you will take detours.
6. The float element must specify the width attribute
Many browsers have bugs when displaying float elements with unspecified 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 extraordinary 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 it properly. Therefore, please ensure that the sum of the widths is less than 99%.
9. Have you reset the default style?
Some attributes, such as margin, padding, etc., will be interpreted differently by different browsers. Therefore, it is best to set all margin and padding to 0, list style to none, etc. before development.
10. Have you forgotten to write a DTD?
If the display results of different browsers are still different no matter how you adjust them, you can check whether you forgot to write the following line of DTD at the beginning of the page:
＜!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"＞