create.php

<?php
    include('logic.php');
    
    if(!Loggedin()) header('Location: /?info=noperm');
    
    if(isset($_POST['content']) & isset($_POST['title'])) {
        $content = $_POST['content'];
        $title = $_POST['title'];

        $pstat = $mysql->prepare('INSERT INTO `blog` (`id`, `title`, `content`) VALUES (NULL, ?, ?)');
        $pstat->bind_param("ss", $title, $content);
        $pstat->execute();
        header('Location: /?info=added');
        exit();
    }
?>

<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Blog</title>
    <link rel="stylesheet" href="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/css/bootstrap.min.css" integrity="sha384-JcKb8q3iqJ61gNV9KGb8thSsNjpSL0n8PARn9HuZOnIxN0hoP+VmmDGMN5t9UJ0Z" crossorigin="anonymous">
</head>

<body>
    <div class="container mt-5">
        <a href="/" class="btn btn-outline-light btn-lg active" role="button" aria-pressed="true">Home</a>

        <form method="POST">
            <input type="text" placeholder="Blog Title" class="form-control my-3 bg-transparent text-black text-center" name="title" required>
            <textarea name="content" placeholder="Blog Description" class="form-control my-3 bg-transparent text-black" cols="30" rows="10" required></textarea>
            <button class="btn btn-success" name="new_post">Add Post</button>
        </form>
    </div>

    <script src="https://code.jquery.com/jquery-3.5.1.slim.min.js" integrity="sha384-DfXdz2htPH0lsSSs5nCTpuj/zy4C+OGpamoFVy38MVBnE+IbbVYUew+OrCXaRkfj" crossorigin="anonymous"></script>
    <script src="https://cdn.jsdelivr.net/npm/popper.js@1.16.1/dist/umd/popper.min.js" integrity="sha384-9/reFTGAW83EW2RDu2S0VKaIzap3H66lZH81PoYlFhbGU+6BZp6G7niu735Sk7lN" crossorigin="anonymous"></script>
    <script src="https://stackpath.bootstrapcdn.com/bootstrap/4.5.2/js/bootstrap.min.js" integrity="sha384-B4gt1jrGC7Jh4AgTPSdUtOBvfO8shuf57BaghqFfPlYxofvL8/KUEfYiJOMMV+rV" crossorigin="anonymous"></script>
</body>

</html>