An extra blank line is added after the html page is imported into the PHP file using include.

The method used for searching on the Internet works.
The footer and header files introduced with include have an extra blank line on the top, which affects the appearance. Put the imported file directly.
Later thought, previously has been using Gb2312 encoding, this use of Utf-8, it is likely to be related to this.
Most of them may be due to css padding settings, but I am not. It was found that it was caused by the Unicode signature (bom. Specific modification method: Open footer or header, click "modify" in Dreamweaver, select "Page attribute", "title/encoding", and include the unicode signature (bom).

Author: wang02011