<button type="button" class="btn bg-primary btn-outline-primary text-light m-auto" data-bs-toggle="modal" data-bs-target="#loginModal">
    Login
</button>
<div class="modal fade" id="loginModal" tabindex="-1" aria-labelledby="loginModalLabel" aria-hidden="true">
    <div class="modal-dialog" role="document">
        <div class="modal-content">
            <div class="modal-header">
                <h5 class="modal-title" id="loginModalLabel">Login</h5>
                <button type="button" class="btn-close" data-bs-dismiss="modal" aria-label="Close"></button>
            </div>
            <div class="modal-body">
                <form method="post" action="<?php echo htmlspecialchars($_SERVER['PHP_SELF']); ?>">
                    <div class="mb-3">
                        <label for="username" class="form-label">Username</label>
                        <input type="text" class="form-control" id="username" name="username" placeholder="Username" required>
                    </div>
                    <div class="mb-3">
                        <label for="password" class="form-label">Password</label>
                        <input type="password" class="form-control" id="password" name="password" placeholder="Password" required>
                    </div>
                    <button type="submit" class="btn bg-primary btn-outline-primary text-light" name="loginButton">Login</button>
                </form>
            </div>
            <div class="modal-footer">
                <button type="button" class="btn btn-warning btn-outline-warning text-light" data-bs-dismiss="modal">Close</button>
            </div>
        </div>
    </div>
</div>