HTML5 Range inputs

HTML

<div id="slider">
	<input class="bar" type="range" id="rangeinput" min="20" max="70" value="50" onchange="rangevalue.value=value"/>
	<span class="highlight"></span>
	<output id="rangevalue">50</output>
</div>

CSS

body {
	background: #2B353E;
	margin: 0;
	padding: 0;
}

#slider {
	width: 400px;
	height: 17px;
	position: relative;
	margin: 100px auto;
	background: #10171D;
	
	-webkit-border-radius: 40px;
	-moz-border-radius: 40px;
	border-radius: 40px;
	
	-webkit-box-shadow: inset 0px 0px 1px 1px rgba(0, 0, 0, 0.9), 0px 1px 1px 0px rgba(255, 255, 255, 0.13);
	-moz-box-shadow: inset 0px 0px 1px 1px rgba(0, 0, 0, 0.9), 0px 1px 1px 0px rgba(255, 255, 255, 0.13);
	box-shadow: inset 0px 0px 1px 1px rgba(0, 0, 0, 0.9), 0px 1px 1px 0px rgba(255, 255, 255, 0.13);
}

#slider .bar {
	width: 388px;
	height: 5px;
	background: #333;
	position: relative;
	top: -4px;
	left: 4px;	
	
	background: #1d2e38;
	background: -moz-linear-gradient(left, #1d2e38 0%, #2b4254 50%, #2b4254 100%);
	background: -webkit-gradient(linear, left top, right top, color-stop(0%,#1d2e38), color-stop(50%,#2b4254), color-stop(100%,#2b4254));
	background: -webkit-linear-gradient(left, #1d2e38 0%,#2b4254 50%,#2b4254 100%);
	background: -o-linear-gradient(left, #1d2e38 0%,#2b4254 50%,#2b4254 100%);
	background: -ms-linear-gradient(left, #1d2e38 0%,#2b4254 50%,#2b4254 100%);
	background: linear-gradient(left, #1d2e38 0%,#2b4254 50%,#2b4254 100%);
	filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#1d2e38', endColorstr='#2b4254',GradientType=1 );	
	
	-webkit-border-radius: 40px;
	-moz-border-radius: 40px;
	border-radius: 40px;
}

#slider .highlight {
	height: 2px;
	position: absolute;
	width: 388px;
	top: 6px;
	left: 6px;
		
	-webkit-border-radius: 40px;
	-moz-border-radius: 40px;
	border-radius: 40px;
	
	background: rgba(255, 255, 255, 0.25);
}

input[type="range"] {
	-webkit-appearance: none;
	background-color: black;
	height: 2px;
}

input[type="range"]::-webkit-slider-thumb {
	-webkit-appearance: none;
	position: relative;
	top: 0px;
	z-index: 1;
	width: 11px;
	height: 11px;
	cursor: pointer;
	-webkit-box-shadow: 0px 6px 5px 0px rgba(0,0,0,0.6);
	-moz-box-shadow: 0px 6px 5px 0px...