Table width is always at 100%

[Trap]

Hi,

I am enhancing an website made from others.

I want to put a table with this CSS property:

..tooltip table {
font-size: 9px;
color: black;
table-layout: auto; <-------------- useful ?
width: 20%; <-------------- note this
}

..tooltip td {
font-size: 9px;
color: black;
}

..tooltip tr {
font-size: 9px;
color: black;
}

note that I "forked" the table width to 20%. But when I show it on the
browser, that table is *always* at 100% of width (entire screen
width!).

Why is it doing this?