Input table is not appearing correctly on mobile view

On this form here http://forms.sybares.com/82891783262366, something annoying happens when you apply via a mobile: when the Input Table #input_359 (title Rythme des services (semaine) ) has not every row completed, the mobile users can not validate their form, because the preview button doesn't function. 

Please try inserting the below CSS:

th.form-matrix-column-headers {

    min-width: 35px;

}

To your custom CSS field.

It should be working like this:

Let us know how it worked.

Thank you!