@import url("https://fonts.googleapis.com/css?family=Lato&display=swap");
* {
    box-sizing: border-box;
}
body {
    background-image: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    font-family: "Lato", sans-serif;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100vh;
    overflow: hidden;
    margin: 0;
}
h2 {
    position: absolute;
    top: 10px;
}
.range-container {
    position: relative;
}
input[type="range"] {
    width: 300px;
    margin: 18px 0;
    -webkit-appearance: none;
}
input[type="range"]:focus {
    outline: none;
}
input[type="range"] + label {
    background-color: #fff;
    position: absolute;
    top: -25px;
    left: 110px;
    width: 80px;
    padding: 5px 0;
    text-align: center;
    border-radius: 4px;
    box-shadow: 0 0 5px rgba(0, 0, 0, 0.3);
} /* Chrome & Safari */
input[type="range"]::-webkit-slider-runnable-track {
    background: purple;
    border-radius: 4px;
    width: 100%;
    height: 10px;
    cursor: pointer;
}
input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    height: 24px;
    width: 24px;
    background: #fff;
    border-radius: 50%;
    border: 1px solid purple;
    margin-top: -7px;
    cursor: pointer;
} /* Firefox */
input[type="range"]::-moz-range-track {
    background: purple;
    border-radius: 4px;
    width: 100%;
    height: 13px;
    cursor: pointer;
}
input[type="range"]::-moz-range-thumb {
    -webkit-appearance: none;
    height: 24px;
    width: 24px;
    background: #fff;
    border-radius: 50%;
    border: 1px solid purple;
    margin-top: -7px;
    cursor: pointer;
} /* IE */
input[type="range"]::-ms-track {
    background: purple;
    border-radius: 4px;
    width: 100%;
    height: 13px;
    cursor: pointer;
}
input[type="range"]::-ms-thumb {
    -webkit-appearance: none;
    height: 24px;
    width: 24px;
    background: #fff;
    border-radius: 50%;
    border: 1px solid purple;
    margin-top: -7px;
    cursor: pointer;
}

const range = document.getElementById('range')
range.addEventListener('input', (e) => {
const value = +e.target.value
const label = e.target.nextElementSibling
const range_width = getComputedStyle(e.target).getPropertyValue('width')
const label_width = getComputedStyle(label).getPropertyValue('width')
const num_width = +range_width.substring(0, range_width.length - 2)
const num_label_width = +label_width.substring(0, label_width.length - 2)
const max = +e.target.max
const min = +e.target.min
const left = value * (num_width / max) - num_label_width / 2 + scale(value, min, max, 10, -10)
label.style.left = `${left}px`
label.innerHTML = value
})
const scale = (num, in_min, in_max, out_min, out_max) => {
return (num - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
}