Profile: nicolaS-3

Problem:
The user would like to apply custom CSS to one select field inside a form.

Solution:
You can target custom fields using the following selector:

select[name=wpcf-book-status] {
    height: 145px;
}

Where book-status is the slug of the field.

And you can target taxonomies with their slugs:

select[name="category[]"] {
    border: 1px solid red;
    padding: 10px;
    margin: 10px;
}

Where category is the taxonomy's slug. Note that you must add [] to the taxonomy slug. Because taxonomies accept multiple values by design.