op: 75px; padding-top: 1.25em;
	background: linear-gradient(to right,
		transparent, transparent 50%,
		black 50%, black 52%,
		transparent 52%);
	background-size: 100% 1em;
	background-repeat: no-repeat;}
.p00 {left: 0;}
.p10 {left: 10%;}
.p20 {left: 20%;}
.p30 {left: 30%;}
.p40 {left: 40%;}
.p50 {left: 50%;}
.p60 {left: 60%;}
</style>
 </head>
 <body>

<section id="spectrum">

<div id="ex01">
<b class="p00">0% red</b>
<b class="p10">10% orange</b>
<b class="p20">20% yellow</b>
<b class="p30">30% green</b>