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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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Adding Classes

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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.

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Babel includes JSX processing.

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Packages

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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.

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HTML 

              
                <div role="tooltip">吹き出しです</div>
<div class="field-row">
	<input checked type="checkbox" id="example2">
	<label for="example2">チェック済み</label>
</div>
<div class="field-row">
	<input disabled type="checkbox" id="example3">
	<label for="example3">チェック不可</label>
</div>
<div class="field-row">
	<input checked disabled type="checkbox" id="example4">
	<label for="example4">チェック変更不可</label>
</div>
<div class="field-row">
	<select>
		<option>5 - 5番目</option>
		<option>4 - 4番目</option>
		<option selected>3 - 3番目</option>
		<option>2 - 2番目</option>
		<option>1 - 1番目</option>
	</select>
</div>
<div class="field-row">
	<fieldset>
		<legend>グループ</legend>
		<div class="field-row">
			<input id="radio8" type="radio" name="fieldset-example2">
			<label for="radio8">1つ目</label>
		</div>
		<div class="field-row">
			<input id="radio9" type="radio" name="fieldset-example2">
			<label for="radio9">2つ目</label>
		</div>
		<div class="field-row">
			<input id="radio10" type="radio" name="fieldset-example2">
			<label for="radio10">3つ目</label>
		</div>
		<div class="field-row">
			<input id="radio11" type="radio" name="fieldset-example2">
			<label for="radio11">14目</label>
		</div>
	</fieldset>
</div>
<div role="progressbar" class="animate">
	<div style="width: 60%"></div>
</div>

<div class="window" style="max-width: 400px">
	<div class="title-bar">
		<div class="title-bar-text">サンプル</div>
		<div class="title-bar-controls">
			<button aria-label="Minimize"></button>
			<button aria-label="Maximize"></button>
			<button aria-label="Close"></button>
		</div>
	</div>
	<div class="window-body">
		<menu role="tablist">
			<button role="tab" aria-controls="music" aria-selected="true">タブ1</button>
			<button role="tab" aria-controls="dogs">タブ2</button>
			<button role="tab" aria-controls="food">タブ3</button>
		</menu>
		<article role="tabpanel" id="music">
			<p>タブ1の中身です</p>
			<fieldset>
				<legend>グループ</legend>
				<div class="field-row">
					<input id="radio25" type="radio" name="fieldset-example2">
					<label for="radio25">1つ目</label>
				</div>
				<div class="field-row">
					<input id="radio26" type="radio" name="fieldset-example2">
					<label for="radio26">2つ目</label>
				</div>
				<div class="field-row">
					<input id="radio27" type="radio" name="fieldset-example2">
					<label for="radio27">3つ目</label>
				</div>
				<div class="field-row">
					<input id="radio28" type="radio" name="fieldset-example2">
					<label for="radio28">4つ目</label>
				</div>
			</fieldset>
			<section class="field-row">
				<button>ボタン</button>
				<label>押しても何もないよ</label>
			</section>
		</article>

		<article role="tabpanel" hidden id="dogs">
			<img style="width: 100%" src="https://picsum.photos/200/300?grayscale" />
		</article>

		<article role="tabpanel" hidden id="food">
			<p>
				タブ3の中身です
			</p>
			<iframe width="100%" height="200" src="https://www.youtube.com/embed/TODJBQ0tnow" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>
		</article>
		<section class="field-row" style="justify-content: flex-end">
			<button>適応</button>
			<button>キャンセル</button>
		</section>
	</div>
</div>
!

CSS 

              
                body {
	width: 70%;
	margin: auto;
	margin-top: 3rem;
	background: #efefef;
}
div {
	margin-bottom: 1rem;
}
!

JS 

              
                const tabButtons = document.querySelectorAll("[role=tab]");
tabButtons.forEach((tabButton) => {
	tabButton.addEventListener("click", (e) => {
		e.preventDefault();
		const tabContainer = e.target.parentElement.parentElement;
		const targetId = e.target.getAttribute("aria-controls");
		tabButtons.forEach((_tabButton) =>
			_tabButton.setAttribute("aria-selected", false)
		);
		tabButton.setAttribute("aria-selected", true);
		tabContainer
			.querySelectorAll("[role=tabpanel]")
			.forEach((tabPanel) => tabPanel.setAttribute("hidden", true));
		tabContainer
			.querySelector(`[role=tabpanel]#${targetId}`)
			.removeAttribute("hidden");
	});
});
!
999px

Console