Untitled

<!DOCTYPE html>
<html>
<head>
    <title>Kasus Tangga</title>
    <style type="text/css">
        body{
            font-family: verdana;
            font-size: 23px;
            background-color: skyblue;
        }
        .kotak{
            width: 25px;
            height: 25px;
            margin: 2px;
            display: inline-block;
        }
        input.button{
            color: black;
            background: white;
            border: 2px darkgray outset;
            padding: 5px 20px;
            font-size: 14px;
            transition: 0.5s;
            border-radius: 7px;
        }
        input.button:hover{
            color: white;
            background: black;
        }
</style>
</head>
<body>

<form method="post">
    <table>
        <tr>
            <th colspan="2">Tangga Berwarna</th>
        </tr>
        <tr>
            <td>Jumlah Anak Tangga&emsp;</td>
            <td><input type="number" name="tangga" id="tangga" size="5"></td>
        </tr>
        <tr>
            <td>Warna</td>
            <td><input type="radio" name="warna" id="warna" value="green">Hijau&emsp;<input type="radio" name="warna" id="warna" value="purple">Ungu&emsp;<input type="radio" name="warna" id="warna" value="yellow">Kuning&emsp;<input type="radio" name="warna" id="warna" value="blue">Biru&emsp;<input type="radio" name="warna" id="warna" value="gray">Abu</td>
        </tr>
        <tr>
            <td colspan="2"><input type="submit" class="button" name="button" id="button" value="Buat Tangga">
            </td>
        </tr>
    </table>
    <?php
    $tangga = $_POST['tangga'];
    $warna = $_POST['warna'];

    for ($a = 0; $a < $tangga; $a++)
    {
        for ($b = 0; $b < $a; $b++)
        {
            echo "<div class = 'kotak' style='background-color: $warna'></div>";
        }
        echo "<div class='kotak' style='background-color: $warna'></div></br>";
    }
    ?>
</form>
</body>
</html>