使用JS确定范围滑块背景宽度

<input type="range" id="slider" min="0" max="100" value="50">
<div id="slider-bg"></div>

const slider = document.getElementById("slider");
const sliderBg = document.getElementById("slider-bg");

slider.addEventListener("input", updateSliderBg);

function updateSliderBg() {
  const value = slider.value;
  const width = (value / 100) * slider.offsetWidth;
  sliderBg.style.width = width + "px";
}