Validation errors slide behind content below.

hello, i am developing a custom theme locally on my computer. I am using the contact form 7 plugin, the problem i am facing is that when form validation errors pop up, the slide down behind the content below. i tried giving the div that contains the form a z-index of 1 and 999. that didnt solve the issue either.
can any one help me on this issue?
any help will be much appreciated, thanks.

https://wordpress.org/plugins/contact-form-7/