WordPress : Add id & class to form in Contact Form 7

Add id and class to Contact Form 7 elements

Example:

contact-form-7 id=”1234″ title=”Contact form 1″ html_id=”contact-form-1234″ html_class=”form contact-form”

Source:
contactform7.com/faq/can-i-add-id-and-class-attributes-to-a-form-element