HTML5 popup contact form

Code

        
<div class="container-box rotated">
<button type="button" class="btn btn-primary" data-bs-toggle="modal" data-bs-target="#popupModal">
    Contact Us
</button>
</div>

<!-- Popup Modal-->
<div class="modal fade" id="popupModal" tabindex="-1" aria-labelledby="popupModalLabel" aria-hidden="true">
    <div class="modal-dialog">
        <div class="modal-content">
            <div class="modal-header">
                <h5 class="modal-title" id="popupModalLabel">Contact Us</h5>
                    <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
            </div>
            <div class="modal-body">
                <form id="contact_form" name="contact_form" method="post">
                    <div class="mb-5">
                        <label for="email_addr">Email address</label>
                        <input type="email" required maxlength="50" class="form-control" id="email_addr" name="email"
                            placeholder="name@example.com">
                    </div>
                    <div class="mb-5">
                        <label for="name_input">Name</label>
                        <input type="text" required maxlength="50" class="form-control" id="name_input" name="name"
                            placeholder="Name">
                    </div>
                    <div class="mb-5">
                        <label for="phone_input">Phone</label>
                        <input type="tel" required maxlength="50" class="form-control" id="phone_input" name="Phone"
                            placeholder="Phone">
                    </div>
                    <div class="mb-5">
                        <label for="message">Message</label>
                        <textarea class="form-control" id="message" name="message" rows="3"></textarea>
                    </div>
                    <button type="submit" class="btn btn-primary">Submit</button>
                </form>
            </div>
        </div>
    </div>
</div>

<style>

.container-box
{
	display:inline-block; 
	padding:10px; 
	background: rgba(255, 255, 255, .8);
	border: 1px solid #fff;	
	position: fixed;
  	top: 15%;
  	left: 0;

}

.rotated
{
	-moz-transform:rotate(-90deg);
    -ms-transform:rotate(-90deg);
    -o-transform:rotate(-90deg);
    -webkit-transform:rotate(-90deg);
    transform-origin: top left;  
}
</style>