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HTML

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HTML preprocessors can make writing HTML more powerful or convenient. For instance, Markdown is designed to be easier to write and read for text documents and you could write a loop in Pug.

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About the <head>

In CodePen, whatever you write in the HTML editor is what goes within the <body> tags in a basic HTML5 template. If you need things in the <head> of the document, put that code here.

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Insecure Resource

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CSS

About CSS Preprocessors

CSS preprocessors help make authoring CSS easier. All of them offer things like variables and mixins to provide convenient abstractions.

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CSS Base

About CSS Base

It's a common practice to apply CSS to a page that styles elements such that they are consistent across all browsers. We offer two of the most popular choices: normalize.css and a reset. Or, choose Neither and nothing will be applied.

Vendor Prefixing

About Vendor Prefixing

To get the best cross-browser support, it is a common practice to apply vendor prefixes to CSS properties and values that require them to work. For instance -webkit- or -moz-.

We offer two popular choices: Autoprefixer (which processes your CSS server-side) and -prefix-free (which applies prefixes via a script, client-side).

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JavaScript

About JavaScript Preprocessors

JavaScript preprocessors can help make authoring JavaScript easier and more convenient. For instance, CoffeeScript can help prevent easy-to-make mistakes and offer a cleaner syntax and Babel can bring ECMAScript 6 features to browsers that only support ECMAScript 5.

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Babel is required to process package imports. If you need a different preprocessor remove all packages first.

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You can apply a script from anywhere on the web to your Pen. Just put a URL to it here and we'll add it, in the order you have them, before the JavaScript in the Pen itself.

If the script you link to has the file extension of a preprocessor, we'll attempt to process it before applying.

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HTML 

              
                <form action="#" class="form">
    <div class="form-group">
      <label for="name">Nombre *</label>
      <input type="text" class="form-input" id="name" placeholder="Introduce tu nombre" minlength="3" required>
    </div>
    <div class="form-group">
      <label for="surname">Apellidos</label>
      <input type="text" class="form-input" id="surname" placeholder="Introduce tus apellidos">
    </div>
    <div class="form-group">
      <label for="birthdate">Fecha de nacimiento *</label>
      <input type="text" class="form-input" id="birthdate" placeholder="Introduce tu fecha de nacimiento" aria-label="Utiliza el formato DD/MM/AAAA" title="Formato DD/MM/AAAA" pattern="^(0?[1-9]|[12]\d|3[01])[\/](0?[1-9]|1[0-2])[\/](19|20)\d{2}$" required>
    </div>
    <div class="form-group">
      <label for="email">Email *</label>
      <input type="email" class="form-input" id="email" placeholder="Introduce tu email" required>
    </div>
    <div class="form-group">
      <label for="favouriteNumber">Número favorito *</label>
      <input type="number" class="form-input" id="favouriteNumber" placeholder="Introduce tu número favorito" min="0" max="999" required>
    </div>
    <div class="form-group">
      <label for="comment">Comentario *</label>
      <textarea class="form-input form-input--textarea" id="comment" rows="3" placeholder="Deja tu comentario" required></textarea>
    </div>
    <div class="form-group form-group--submit">
      <button class="form-button" type="submit">Enviar</button>
    </div>
  </form>
!

CSS 

              
                $c-white: #fff;
$c-black: #333;

$c-border: #e8e8e8;
$c-placeholder: #999;
$c-error: red;
$c-success: #2fe678;

$c-primary: #02ffd0;
$c-primary-hover: #80fee7;

* {
  box-sizing: border-box;
  font-family: Courier;
}

%formInput {
	display: block;
	width: 100%;
	height: 40px;
	border: 1px solid $c-border;
	border-radius: 4px;
	padding: 10px 16px;
	box-shadow: 1px 1px 2px 0 rgba($c-black, 0.2) inset;
	background-color: $c-white;
	background-clip: padding-box;
	color: $c-placeholder;
	font-size: 16px;
	font-weight: normal;
	transition: all 250ms;

	// Placeholder
	&::placeholder {
		color: $c-placeholder;
	}

	// Focus
	&:focus:required {
		border-color: $c-primary;
		outline: 0 none;
	}

	// States
	&:required:placeholder-shown {
		border: 1px solid $c-border;
	}
	&:required:not(:placeholder-shown):invalid {
		border: 1px solid $c-error;
		color: $c-error;
		box-shadow: 0 0 0 1px;
	}
	&:required:not(:placeholder-shown):valid {
		border: 1px solid $c-success;
		color: $c-success;
		box-shadow: 0 0 0 1px;    
	}
  &:required:focus:invalid {
		border: 1px solid $c-error;
		color: $c-error;
		box-shadow: 0 0 0 1px;
	}
}

.form {
  max-width: 30rem;
  margin: 2rem auto;
	&-group {
		margin-bottom: 24px;

		label {
			display: block;
			margin-bottom: 6px;
			font-weight: bold;
		}

		// MODIFIERS
		&--submit {
			display: flex;
			justify-content: flex-end;
		}
	}

	&-input {
		@extend %formInput;

		// Disabled
		&:disabled {
			opacity: 0.7;
			cursor: not-allowed;
		}
	}
  
  &-button {
    padding: 1.5rem 2rem;
    font-size: 1.125rem;
    cursor: pointer;
    background-color: $c-primary;
    border: 0;
    border-radius: 0.125rem;
    transition: background-color 300ms;
    
    &:hover, 
    &:focus {
      background-color: $c-primary-hover;
    } 
  }

	// MODIFIERS
	textarea {
		&.form-input {
			height: 20rem;
			resize: none;
		}
	}
}
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JS
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999px

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