【HTML】input / textarea

HTML

■ input

placeholder属性

From HTML5 
 * テキスト入力欄に、初期表示する内容を指定する

type属性

type="range" 
<input id="brightness" type="range" value="0" min="-100.0" max="100.0" step="0.1" />
type="number" 
<input id="brightness" type="number" value="0" />
サンプル
https://blogs.yahoo.co.jp/dk521123/37818958.html
<!DOCTYPE html>
<html lang="jp">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<title>Demo</title>
</head>
<body>
<input id="brightness" type="range" value="0" min="-100.0" max="100.0" step="0.1" />
<p id="result">abc</p>
<script type="text/javascript">
var brightness = document.getElementById("brightness");
var result = document.getElementById("result");
brightness.addEventListener("input", function() {
  result.innerHTML = brightness.value;
}, false);
</script>
</body>
</html>

■ textarea

textareaの回りが下寄せになる

解決案 
textarea {
  vertical-align:top;
}

参考文献

input

placeholder
http://www.htmq.com/html5/input_placeholder.shtml
type
https://jsfiddle.net/girlie_mac/GKY2A/

textarea

http://honttoni.blog74.fc2.com/blog-entry-169.html
https://qiita.com/YoshiyukiKato/items/e0a850e9c3882b9bda2f

関連記事

HTML覚書

https://blogs.yahoo.co.jp/dk521123/25393518.html