How to make all Contact 7 Fields the same size?

I have this site, and I am having trouble with making all fields in contact form 7 to have the same size, like "Submit" button as example. I tried to insert this CSS that I found somewhere, but don't make any changes.

.wpcf7-form {
max-width: 750px;
margin: auto;
}

How to make all fields in Contact form in my page the same height and width? Thanks

Solution

What i saw in your linked site that it is not getting full width because of your label tag. following css will help you to get same width.

form.wpcf7-form label {
    width: 100%;
}

Hope this helps.