<style>
	.demo_css_sprt, .demo_css_sprt div	{
		border: 1px dotted red;
		padding: 1em;
	}
	.demo_css_sprt div	{
		margin: 1em 0;
	}
	.demo_css_sprt p	{
		border: 1px dashed blue;
		padding: 1em;
	}
	.demo_css_sprt span	{
		border: 1px dashed green;
		margin: 1em;
	}
	.demo_css_sprt .bg:first-child	{
		background: mistyrose;
	}
</style>
<div class="demo_css_sprt">
	要素1
	<div class="bg">要素2</div>
	<div class="bg">要素3</div>
	<div class="bg">要素4
		<p class="bg">要素5
			<span class="bg">要素6</span>
			<span class="bg">要素7</span>
		</p>
	</div>
	<p class="bg">要素8</p>
</div>