BMI kalkulačka plugin WordPress

<?php
/*
Plugin Name: BMI Calculator
Plugin URI: https://www.example.com/
Description: Tento plugin umožňuje výpočet BMI.
Version: 1.0
Author: Autor
Author URI: https://www.example.com/
*/

function bmi_calculator_form() {
    $output = '
    <form method="post">
        <label for="height">Výška (v cm):</label>
        <input type="text" id="height" name="height" required>
        <br><br>
        <label for="weight">Váha (v kg):</label>
        <input type="text" id="weight" name="weight" required>
        <br><br>
        <input type="submit" value="Spočítat BMI">
    </form>
    ';

    if (isset($_POST['height']) && isset($_POST['weight'])) {
        $height = floatval($_POST['height']);
        $weight = floatval($_POST['weight']);
        $bmi = $weight / (($height / 100) * ($height / 100));
        $output .= "<p>Vaše BMI je: $bmi</p>";
    }

    return $output;
}

add_shortcode('bmi_calculator', 'bmi_calculator_form');