<style>
	.demo_css_sprt {
		border: 1px dotted red;
		padding: 1em;
	}
	.demo_css_sprt a {
		border: 1px dashed blue;
		display: block;
		margin-bottom: 1em;
		padding: 1em;
	}
	.demo_css_sprt *:focus {
		background: mistyrose;
		outline: solid 1px red;
		color: red;
	}
</style>
<div class="demo_css_sprt">
	<a href="#">タブキーなどでフォーカスすると反映される</a>
	<input type="checkbox" checked="checked">
	<input type="checkbox">
	<input type="checkbox" disabled="disabled">
	<input type="radio" checked="checked">
	<input type="radio">
	<input type="radio" disabled="disabled">
	<input type="text">
	<input type="text" disabled="disabled">
	<button>button</button>
</div>