CSS positioning problems.

When preparing the webpage, I thought that after setting the parent's position as relative, the float in the CSS OF THE FIRST Div can be completely left empty, by default, the first div is placed on the left.

I found out today that this idea is wrong, and left or right must be written for every Div float of the child generation. Otherwise, the following Div cannot be located.

Finally, I understood why my bot_right cannot be followed by bot_left. Call. Cheers for my solution to this childish problem.

In a word, when locating a DIV, you must write all the rewritten content, float: Left; position: relative; and so on.