When tables are nested, why can't the tables inside be aligned at the top? _html/css_WEB-ITnose

There is a table nested in td. How to align the td inside the table with the th outside the table?

Reply to the discussion (solution)

Just go to the code. ..

margin:auto ??

can be aligned. I guess there is too much content in other cells in the row where the td is located. The row is raised, so the table inside Using 100% will not fill up the
. The actual situation requires looking at the code

*{margin:0;padding:0;}

In addition, add valign="top" to the tr of the td in the line where the embedded table is located