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Any URL's added here will be added as <link>s in order, and before the CSS in the editor. If you link to another Pen, it will include the CSS from that Pen. If the preprocessor matches, it will attempt to combine them before processing.

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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.

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Use npm Packages

We can make npm packages available for you to use in your JavaScript. We use webpack to prepare them and make them available to import. We'll also process your JavaScript with Babel.

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HTML Settings

Here you can Sed posuere consectetur est at lobortis. Donec ullamcorper nulla non metus auctor fringilla. Maecenas sed diam eget risus varius blandit sit amet non magna. Donec id elit non mi porta gravida at eget metus. Praesent commodo cursus magna, vel scelerisque nisl consectetur et.

  <input placeholder="Username" type="text">
  <input placeholder="Password" type="password">
	<textarea placeholder="Description"></textarea>

              form {
	text-align: center;
	width: 50%;
	margin: 0 auto;

textarea {
	display: block;
	width: 100%;
	border: 0;
	padding: 10px 5px;
  background: white no-repeat;
  /* 2 imgs : 1px gray line (normal state) AND 2px green line (focus state) */
	background-image: linear-gradient(to bottom, #1abc9c, #1abc9c), linear-gradient(to bottom, silver, silver);
	/* sizes for the 2 images (default state) */
	background-size: 0 2px, 100% 1px;
	/* positions for the 2 images. Change both "50%" to "0%" or "100%" and tri again */
	background-position: 50% 100%, 50% 100%;

	/* animation solely on background-size */
  transition: background-size 0.3s cubic-bezier(0.64, 0.09, 0.08, 1);


  /* sizes for the 2 images (focus state) */
	background-size: 100% 2px, 100% 1px;
	outline: none;
We use two background gradients, for two states. Each background visibility is ruled by the background-size.

- default state: 1px silver bottom background is visible.
- focus state: 2px color bottom background is visible

The size of the background is animated with "transition". The y-size remains always the same. The x-size is changed.

- default state
  - silver background is 100% wide
  - color background is 0% wide.
- focus state
  - silver background is 0% wide
	- color background is 100% wide

Animation is solely on the background-size, making it grow from 0 to 100% on focus and shrink back to 0% on blur.

The grow/shrink goes from the center to the borders.
To make it go from/to a side, replace the "50% 100%" with "0 100%" or "100% 100%" (for left or right respectively) on the background-position.

This works on <input> and on <textarea> alike.
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