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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>

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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

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.

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Using packages here is powered by esm.sh, which makes packages from npm not only available on a CDN, but prepares them for native JavaScript ESM usage.

All packages are different, so refer to their docs for how they work.

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HTML 

              
                <ul class="list">
  <li class="list__item">
    <h2>アイテム</h2>
    <input type="text" value="" class="" name="sample" id="sample" placeholder="例）test">
    <p class="delete">
      <button type="button" class="js-delete-btn">削除</button>
    </p>
  </li>
</ul>

<p class="add">
  <button type="button" class="js-add-btn">追加</button>
</p>
!

CSS 

              
                p {
  margin: 0;
}

input {
  padding: .8em;
  border: 1px solid #bbb;
  border-radius: 3px;
}

h2 {
  font-size: 13px;
  margin-top: 0;
}

.list {
  list-style: none;
  padding-left: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 1em;
}

.list__item {
  display: inline-block;
  padding: 1em;
  box-shadow: 0 0 3px rgba(0,0,0, .2);
  border-radius: 5px;
}

/* li.list__itemが1つの時に「削除」ボタンを非表示 */
.list__item:only-of-type .delete{
  display:none;
}

button {
  border: 0px solid transparent;
  padding: .5em .8em;
  border-radius: 3px;
}
.delete {
  margin-top: .5em;
  text-align: right;
}
.delete button {
  background-color: #ddd;
  box-shadow: 0 3px 0 #999;
  color: #444;
}

.add button {
  background-color: #2e95b5;
  box-shadow: 0 3px 0 #066c8c;
  color: #fff;
}
!

JS 

              
                // 追加ボタンを押した時
$('.js-add-btn').on('click',function() {
  // ul.listの中の一番下のli.list__itemをクローン
  var clone = $(this).parent().prev('ul.list').find('li.list__item:last-of-type').clone(true);
  // クローンした要素のinputのvalue属性を空にする
  clone.find('input[type="text"]').val('');
  // クローンしてinputを操作した要素をul.listの一番下に追加
  clone.appendTo('.list');
});

// 削除ボタンを押した時
$('.js-delete-btn').on('click',function() {
  if($('.list__item').length > 1 ) {//li.list__itemが1つより多い時
  // 削除の確認
    var deleteConfirm = confirm('削除してよろしいでしょうか？');
    if(deleteConfirm == true) {// OKを押したら
      // 削除ボタンをクリックしたli.list__itemを削除
      $(this).closest('.list__item').remove();
    }
  }
});
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999px

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