slider-progress-fill

<!DOCTYPE html>
<html lang="pt-br">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Slider com Gradiente</title>
  <style>
    /* Estilo do Slider */
    .slider {
  -webkit-appearance: none;
  width: 100%;
  height: 15px;
  border-radius: 5px;
  background: #d3d3d3;
  outline: none;
  opacity: 0.7;
  -webkit-transition: .2s;
  transition: opacity .2s;
}

.slider:hover {
  opacity: 1;
}

.slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 25px;
  height: 25px;
  border-radius: 50%;
  background: #ffffff;
  cursor: pointer;
}

.slider::-moz-range-thumb {
  width: 25px;
  height: 25px;
  border-radius: 50%;
  background: #4CAF50;
  cursor: pointer;
}
  </style>
</head>
<body>


  <div class="slidecontainer">
    <input type="range" min="0" max="600000" value="300000" step="1000" class="slider" id="myRange">
    <p>Value: <span id="demo"></span></p>
  </div>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script>
var slider = document.getElementById("myRange");
var output = document.getElementById("demo");
output.innerHTML = slider.value;

function updateGradient(rangeValue) {
  const percentage = (rangeValue - slider.min) / (slider.max - slider.min) * 100;
  slider.style.backgroundImage = `linear-gradient(90deg, #4CAF50 ${percentage}%, transparent ${percentage}%)`;
}

// Update gradient onload
updateGradient(slider.value);

// Update gradient oninput
slider.addEventListener('input', (e) => {
  output.innerHTML = e.target.value;
  updateGradient(e.target.value);
});
</script>

</body>
</html>