Pen Settings



CSS Base

Vendor Prefixing

Add External Stylesheets/Pens

Any URLs added here will be added as <link>s in order, and before the CSS in the editor. You can use the CSS from another Pen by using its URL and the proper URL extension.

+ add another resource


Babel includes JSX processing.

Add External Scripts/Pens

Any URL's added here will be added as <script>s in order, and run before the JavaScript in the editor. You can use the URL of any other Pen and it will include the JavaScript from that Pen.

+ add another resource


Add Packages

Search for and use JavaScript packages from npm here. By selecting a package, an import statement will be added to the top of the JavaScript editor for this package.


Auto Save

If active, Pens will autosave every 30 seconds after being saved once.

Auto-Updating Preview

If enabled, the preview panel updates automatically as you code. If disabled, use the "Run" button to update.

Format on Save

If enabled, your code will be formatted when you actively save your Pen. Note: your code becomes un-folded during formatting.

Editor Settings

Code Indentation

Want to change your Syntax Highlighting theme, Fonts and more?

Visit your global Editor Settings.


                <h1>HTML, CSS, Forms - A Test</h1>

<p>When using <code>::placeholder</code> in connection with the attribute of the same name (<code>placeholder="your text"</code>) being put in an input field, we can tell our users what or how they should fill an input field in our precious webforms.</p>

<p>On top of that we love to tell people which fields they <strong>have to</strong> fill out in order to be able to submit said webform to us. Therefore we got the <code>:required</code> pseudo-class to style form elements which we deem important – you sure want to write <em>required</em> into the input then for the styling to take effect. <code>&lt;input required /&gt;</code> will do by the way, as it is a boolean and therefore it defaults to <em>true</em> when it's there.</p>

<p>I think I found a nice way to combine both the pesudo-element with the pseudo-class in order to give people a hint on required fields.</p>

<p><strong>Notice:</strong> <a href="">Browser Support</a> is an issue when it comes to IE. <em class="spoken">"&#$§¥ you IE!."</em> Anything lower than IE10 won't understand those selectors. <em>*shakes fist towards the sky*</em></p>

<p>Enough with the chatter, here we go with the example form:</p>

<hr />

<form class="myform" action="" method="post" name="bestformeva">
    <legend>Please tell me a few things about you! Required fields are marked with a blue border.</legend>
    <label for="name">First, I need your full name.</label>
    <input type="text" id="name" name="name" required placeholder="Your Name"/>
    <label for="street">It's optional but if you wanted to be very accurate, you may enter your street address here. Otherwise you can also skip this field.</label>
    <input type="text" id="street" name="street" placeholder="Optional: Street Address" />
    <label for="city">Now, I do need to know which city you live in.</label>
    <input type="text" id="city" name="city" required placeholder="Name the city you live in" />
    <label for="zip">Please provide the zip-code for your city. This field accepts only numbers.</label>
    <input type="number" id="zip" name="zip" required placeholder="ZIP Code. Numbers only" />
    <label for="email">Now, please tell me your email address so I can get back to you when needed.</label>
    <input type="email" id="email" name="email" placeholder="blablabla@something.whatever" required />
    <label for="textarea">If there is anything else you want to tell me, hack away on your keyboard like there's no tomorrow after focussing the following textarea. Maximum characters is 4000.</label>
    <textarea id="textarea" name="textarea" placeholder="This empty textarea is valid, as it is not required to fill it with text in order to submit the form."></textarea>

    <label for="submit">You may now submit your form by hitting the button below.</label>
    <button id="submit" type="submit" name="submit">Submit</button>

<hr />

<p>Interestingly enough the placeholder text for <code>&lt;input type="number" /&gt;</code> does not change its color although the field is set to required in the HTML. The border color though did change.</p>


<p>Now, that I added the <code>:valid</code> and <code>:invalid</code> selectors to the CSS, there's another funky thing going on. The <code>&lt;number></code> input is now marked as invalid although it's empty (apart from the placeholder, which now received the color I set for invalid input values). <strong>STRRRRAAAAANNNGE!</strong></p>

<p>Apart from that you would have to know Regular Expressions in order to prevent the <code>type="text"</code> inputs to take any character. You'd want to prevent people from using numbers for their name, right? <small>There might be a use-case for this (numbers in names that is) but I honestly don't know, so I'd go the way of not preventing the user from typing whatever he thinks his name really is. <em>- Yours Batman1982-0H-Y34H</em></small></p>

<p><strong>Interesting find:</strong> When setting the submit button styles related to the form being valid or invalid you can give users visible feedback on whether they can submit the form or not.</p>


  Let's say Firefox has issues, okay?
input::-moz-focus-inner {
  border: 0;
  padding: 0;

  As little styling as we need
body {
  font-family: sans-serif;
  font-size: 1.25em;
  line-height: 1.55;
  padding: 1.618em 5%;
  max-width: 900px;
  margin: 0 auto;

code {
  font-family: Consolas, Monaco, "Courier New", Courier, monospace;
  background: #f0f0f0;
  font-size: .875em;
  color: #333;
  padding: .25em;

.spoken {
  font-family: "Comic Sans MS";
  text-align: center;
  float: right;
  padding: 2em;
  margin: 1em 0 1em 1em;
  background: #ffa;
  border: .3125em solid #333;
  border-radius: 50% 75%;
  width: 300px;
  transform: rotate(-15deg);

hr {
  border: 0;
  height: .08em;
  background: #ebc533;
  margin: 2em

small {
  font-size: .75em;
  display: block;
  margin: .5em 0;

small em {
  color: #595959;

  The actual form - finally

form {
  margin: 2em 0;

fieldset {
  margin: 0 0 2em;

legend {
  font-weight: bold;
  padding: 0 .5em;

label {
  display: block;
  margin: 1em 0 0;
  cursor: pointer;
  color: #595959;

textarea {
  border: .125em solid #e5e5e5;
  padding: .5em;

textarea {
  box-sizing: border-box;
  resize: vertical;
  width: 50%;
  height: 8em;

  border-color: green;
  color: green;

textarea:not(:focus):invalid {
  border-color: red;
  color: red;

textarea:required {
  border-color: darkblue;

::placeholder {
  color: #777;

  color: orange;
  opacity: 1;

button {
  color: darkblue;
  border: 2px solid darkblue;
  padding: .309em .618em;

form:valid button {
  color: green;
  border-color: green;

form:invalid button {
  color: red;
  border-color: red;