index.html

<!DOCTYPE html>
<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">

    <link rel="stylesheet" media="screen and (min-width: 701px)" href="CSS/styles.css">
    <link rel="stylesheet" media="screen and (max-width: 700px)" href="CSS/styles2.css">

    <script src="JS/calculate.js" defer></script>

    <title>BMI calculator</title>
</head>

<body>
    <div class="content">
        <h1>Simple BMI calculator</h1>

        <div class="calculator">
            <div class="core first">
                <div class="data">

                    <label for="weight">Your weight:</label>
                    <input type="number" id="weight" name="weight" value="60.50" min="1" max="500" step="0.1" required/>kg


                    <label for="height">Your height:</label>
                    <input type="number" id="height" name="height" value="1.75" min="0.5" max="2.2" step="0.01" required/>m
                </div>

            <button id="calculate">Calculate BMI</button>

            </div>

            <hr id="hr"/>

            <div class="core BMImessage">
                <p>
                    <span id="message"></span><span id="bmi"></span><span id="details"></span>
                    <span class="error" id="height_error"></span>
                    <span class="error" id="weight_error"></span>
                </p>
            </div>

        </div>
    </div>
</body>
</html>