I've revisited this question with a new "input" HTML tag
Despite changing everything, CSS still isn't being applied.
HTML Code :
<form action="#" class="contact-one__form row">
<div class="col-lg-6">
<input type="text" placeholder="First name" name="fname">
</div><!-- /.col-lg-6 -->
<div class="col-lg-6">
<input type="text" placeholder="Last name" name="lname">
</div><!-- /.col-lg-6 -->
<div class="col-lg-6">
<input type="text" placeholder="Email address" name="email">
</div><!-- /.col-lg-6 -->
<div class="col-lg-6">
<input type="text" placeholder="Phone number" name="phone">
</div><!-- /.col-lg-6 -->
<div class="col-lg-12">
<textarea name="message" placeholder="Write message"></textarea>
<div class="text-center">
<button type="submit" class="thm-btn contact-one__btn">Submit Now</button>
</div><!-- /.text-center -->
</div><!-- /.col-lg-12 -->
</form>
The result:
https://i.sstatic.net/IFSZV.png
My Contact Form 7 Integration:
<form action="#" class="contact-one__form row">
<div class="col-lg-6">
[text* nomcontact placeholder "Nom"]
</div><!-- /.col-lg-6 -->
<div class="col-lg-6">
[text* prenomcontact placeholder "Prenom"]
</div><!-- /.col-lg-6 -->
<div class="col-lg-6">
[email* emailcontact placeholder "Adresse Email"]
</div><!-- /.col-lg-6 -->
<div class="col-lg-6">
[tel* telcontact placeholder "Numero de Telephone"]
</div><!-- /.col-lg-6 -->
<div class="col-lg-12">
[textarea* textarea-contact placeholder "Votre Message"]
<div class="text-center">
[submit class:thm-btn class:contact-one__btn "Envoyer"]
</div><!-- /.text-center -->
</div><!-- /.col-lg-12 -->
</form>
The Result when I integrate WordFence 7:
https://i.sstatic.net/08lx5.png
Is there any way to apply CSS to the form using Contact Form 7?