Fixed Header width doesn't match parent width

Undalamar

Link to test case: https://jsfiddle.net/tnm2db8g/ https://rsk-spb.com/catalog/opalubka/stenovaya/
Debugger code (debug.datatables.net): https://debug.datatables.net/ekuken
Description of problem: On site FixedHeader break <th> width, but in fiddle all works properly. What problem it could be?

allan

Different styles are being applied when the header is in its 'fixed' mode - on your page, if you scroll it so the header is fixed, you'll see that the table headers have left/right borders. That is all that is needed to break the layout!

In your CSS you have

.catalog__table table, .catalog__table td, table th {
    border: 0;
}

but you need to use:

table.dataTable thead td,
table.dataTable thead th {
    border: 0;
}

Allan

Undalamar

I've tried this, but nothing happens. Only borders dissapear, but width not calculate properly