<form action="sendmail.php" method="post">
    <div class="form-row">
        <div class="form-group col-md-6">
            <label for="inputEmail4">Name</label>
            <input type="text" placeholder="Full Name" name="full_name" class="form-control" id="inputName" required />
        </div>
        <div class="form-group col-md-6">
            <label for="inputEmail4">Phone</label>
            <input type="tel" placeholder="Phone Number" name="phone" class="form-control" id="inputPhone" required />
        </div>
        <div class="form-group col-md-12">
            <label for="inputEmail4">Email</label>
            <input type="email" placeholder="Email Address" name="email" class="form-control" id="inputEmail4" required />
        </div>
        <div class="form-group col-md-12">
            <textarea name="brief" rows="4" placeholder="Enter a brief description about your book" id="" required></textarea>
        </div>
    </div>
    <button type="submit" class="btn btn-primary">Let's Talk To An Expert</button>
</form>