Javascript change webkit style with variables

Summary

I’m working on an input[type=range] that essentially looks like Chrome’s default but the thumb is green until clicked. That’s the end goal. Through a couple answers that are now buried deep in my browser history (hence lack of credit to them) I am able to get it MOSTLY working how I want.

Issue

The onLoad code works how I want it to except for one major issue: It affects all elements, not the individuals. I simply can’t figure out how to get this line:

s.textContent = `.slider::-webkit-slider-thumb { background-color: ${thumb_color} !important; } .slider:-moz-range-thumb {  ${thumb_color} !important; }`;

to be set in the same manner as this line:

this.style.background = 'linear-gradient(to right, #006CBA 0%, #006CBA '+100*(this.value-1)/4 +'%, #efefef ' + 100*(this.value-1)/4 + '%, #efefef 100%)';

Supporting Code

Here are those two lines in my ‘working’ code:

let s = document.createElement("style");
document.head.appendChild(s);
var range_els = document.querySelectorAll('input[type=range]');
for(let i = 0;i < range_els.length; i++) {
    range_els[i].addEventListener("input", () => {
        const slider_value = range_els[i].value;
        let thumb_color;
        if (slider_value == 0) {
            thumb_color = "#9CCF47";
        }
        else {
            thumb_color = "#006CBA";
        }
        //effects the style, not the individual style.  :|
        s.textContent = `.slider::-webkit-slider-thumb { background-color: ${thumb_color} !important; } .slider:-moz-range-thumb {  ${thumb_color} !important; }`;            
    });
    range_els[i].oninput = function() {
        this.style.background = 'linear-gradient(to right, #006CBA 0%, #006CBA '+100*(this.value-1)/4 +'%, #efefef ' + 100*(this.value-1)/4 + '%, #efefef 100%)';
    };
}

<style>
.slider {
  -webkit-appearance: none;
  height: 8px;
  border-radius: 4px;
  background-color: #efefef;
  border: 1px solid #b2b2b2;
}

.slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 8px;
  background-color: #9CCF47;
  cursor: pointer;
}
</style>

<body>
<input type="range" min="1" max="5" value="0" class="slider" name="rangeInput">
</body>

Yes, I know it’s a value that’s less that min. I’m leveraging this for essentially making changing it a requirement (think like instead of 5 radio buttons for a survey). That’s also the reason I want to start with a green thumb: Green means it’s not been touched yet. This is my focus.

Thank you in advance.

Answer

I think you can’t write the ::-webkit-slider-thumb, just like other pseudo-classes, as inline-style. See this thread.

But you can complete your “hack” with the <style> element. Create one for each input and add a unique selector (e.g. id or [name="rangeInput1").

var range_els = document.querySelectorAll('input[type=range]');
range_els.forEach(range_el => {
  let s = document.createElement("style");
  document.head.appendChild(s);
  range_el.addEventListener("input", () => {
    const slider_value = range_el.value;
    let thumb_color;
    if (slider_value == 0) {
      thumb_color = "#9CCF47";
    } else {
      thumb_color = "#006CBA";
    }
    s.textContent = `.slider#${range_el.id}::-webkit-slider-thumb { background-color: ${thumb_color} !important; } .slider#${range_el.id}:-moz-range-thumb {  ${thumb_color} !important; }`;
  });
  range_el.oninput = function() {
    this.style.background = 'linear-gradient(to right, #006CBA 0%, #006CBA ' + 100 * (this.value - 1) / 4 + '%, #efefef ' + 100 * (this.value - 1) / 4 + '%, #efefef 100%)';
  };
});

.slider {
  -webkit-appearance: none;
  height: 8px;
  border-radius: 4px;
  background-color: #efefef;
  border: 1px solid #b2b2b2;
}

.slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 8px;
  background-color: #9CCF47;
  cursor: pointer;
}

<body>
  <input type="range" min="1" max="5" value="0" class="slider" name="rangeInput1" id="rangeInput1">
  <input type="range" min="1" max="5" value="0" class="slider" name="rangeInput2" id="rangeInput2">
</body>

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Answer