The method discussed in the post mentioned by shambalambala is quite clever, however, I have doubts about its effectiveness in replicating the exact image shown. The concept involves adding a shadow to the thumb element to achieve different coloring on the left side of the thumb. This technique requires adding overflow:hidden to either the range or the track to clip the shadow effect. Unfortunately, this clipping also affects the thumb. Therefore, if you desire a thumb that extends beyond the track vertically, as seen in the image where the thumb is a circle with a diameter larger than the track width, this approach may not be suitable.
It seems challenging to find a purely CSS-based solution for this issue. A potential workaround using JavaScript involves creating two overlapping range elements. One would display only the thumb while the other shows only the track. By applying the shadow effect to the track element, you can achieve the desired color differentiation before the thumb. The thumb appearance on the visible range can be customized without setting overflow: hidden, allowing it to extend beyond the track width. Through JavaScript, you can synchronize the values of both range elements so that moving the thumb on one reflects changes on the other.
Below is an example code snippet (optimized for webkit browsers—additional styling might be needed for other browsers):
<html>
<head>
<style>
.styled_range {
position: relative;
padding: 10px;
}
input[type=range] {
-webkit-appearance: none;
width: 600px;
background: transparent;
position: absolute;
top: 0;
left: 0;
}
input[type=range]::-webkit-slider-thumb {
-webkit-appearance: none;
}
input[type=range]:focus {
outline: none;
}
input[type=range]::-webkit-slider-runnable-track {
width: 100%;
height: 12px;
}
.track_range {
pointer-events: none;
}
.track_range::-webkit-slider-runnable-track {
background: #D0D0D0;
border-radius: 6px;
overflow: hidden;
}
.track_range::-webkit-slider-thumb {
-webkit-appearance: none;
background: transparent;
height: 1px;
width: 1px;
box-shadow: -600px 0 0 600px #666666;
}
.thumb_range::-webkit-slider-runnable-track {
background: transparent;
cursor: pointer;
}
.thumb_range::-webkit-slider-thumb {
-webkit-appearance: none;
border: 3px solid #ffffff;
border-radius: 20px;
height: 40px;
width: 40px;
background: #1180AD;
cursor: pointer;
margin: -12px 0px 0px 0px;
}
</style>
</head>
<body>
<form>
<div class="styled_range">
<input type="range" class="track_range"/>
<input type="range" class="thumb_range"/>
</div>
<br/>
<div class="styled_range">
<input type="range" class="track_range"/>
<input type="range" class="thumb_range"/>
</div>
</form>
</body>
<script>
window.onload = function() {
var styledRanges = document.getElementsByClassName('styled_range');
for (var i=0; i<styledRanges.length; i++) {
var thumbRange = null, trackRange = null;
for (var j=0; j<styledRanges[i].children.length; j++) {
var child = styledRanges[i].children[j];
if (child.className === 'thumb_range')
var thumbRange = child;
else if (child.className === 'track_range')
var trackRange = child;
}
thumbRange.oninput = function(thumbRange, trackRange) {
return function(e) {
trackRange.value = thumbRange.value;
};
}(thumbRange, trackRange);
}
}
</script>
</html>