Checkbox table – vertical listing

Hello,

I’m listing checkboxes vertically using the layout for tables suggested by Contact form 7 (CSS):

span.wpcf7-list-item {display: table-row;}
span.wpcf7-list-item * { display: table-cell; text-align:left;}

On Chrome and Firefox, it gives me vertical checkboxes listed in the center of my form, as intended (I’m using ‘text-align: center;’ for this). However, in Safari, the checkboxes insist to be listed on the left side of the form.

Question: How do I make them to be listed centrally in Safari as well?

Thank you.