Table not resizing (sticking to its minimum width°

Hi,

I have a page with nothing but a table in it, and I would like the table to fill the horizontal space of the page; It however stays to its minimum width, and I can’t set the size of individual columns either.

http://www.high-altitudes.com/test-tableaux/

This is with the following bits regarding width in the TablePress custom CSS:

.tablepress {
width: auto;
margin: 0 auto 1em;
}

.tablepress-id-1 .column-1 {
width: 500px;
}

The only thing that kinda works is to set the tablepress width to a big value like 1000px. The table is then much larger and I can manually set the widths for columns, but then the table will not resize if the page is made bigger or smaller.

Am I missing something?

Thanks in advance.