htmlcssborder-boxbox-sizing

Why is the size of the <td>s changing when border is added inside it using the box-sizing property?


I'm using the .click JQuery method to add .clicked to <td> whenever it is clicked. .clicked contains a border and the box-sizing property set to border-box.

When I click two consecutive <td>s either horizontally or vertically, their size seems to change. Why is it so?

Here's my code:

<!-- page.html -->

<!DOCTYPE html>
<html>
    <head>
        <link rel="stylesheet" type="text/css" href="stylesheet.css">
        <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.0/jquery.min.js"></script>
        <script type="text/javascript" src="script.js"></script>
    </head>
    <body>
        <table>
            <tr>
                <td></td>
                <td></td>
            </tr>
            <tr>
                <td></td>
                <td></td>
            </tr>
        </table>
    </body>
</html>

/* stylesheet.css */

td {
    height: 100px;
    width: 100px;
    background-color: red;
}

.clicked {
    border: 5px solid green;
    box-sizing: border-box;
    -moz-box-sizing: border-box;
    -webkit-box-sizing: border-box;
}

// script.js

$(document).ready(function () {
    $("td").click( function() {
        $(this).addClass("clicked");
    });
});

Help shall be appreciated.


Solution

  • Padding (which isn't counted by box-sizing: border-box is messing things up. Your td's have a padding of 1px if you set this to 0 then the weird behaviour goes away.

    https://jsfiddle.net/x11us50v/