[PLUGIN: Contact Form 7 Calendar] input width issue

I am using contact form 7, along with CF7 Calender (https://www.ads-software.com/extend/plugins/cf7-calendar/)
The issue I am having is that I have the widths set for all the input fields in the forms, however when I set the CF7cal to show the date & time the resulting text extends past the width of the input cell –
How can I alter the width of JUST the CF7cal input cells, without messing with the rest of the form input widths?

I have tried creating a new style class, but it is not changing the widths – the current width of the CF7cal cells are 159px – I need it to change to about 210px – 220px to be in-line with the other input areas (the other areas are 250px).