/*
 * 16 February 2022
 * Range Slider Progress in Chrome with pure CSS
 *
 * === This CodePen demonstrates how we can implement range slider "progress fill" in Webkit browsers using a `clip-path` and a `box-shadow` ===
 *
 * === There is an open issue about Standardizing input[type="range"] styling (https://github.com/w3c/csswg-drafts/issues/4410). For all I know, it hasn't been implemented yet ===
 *
 * === This demo is meant for Chrome browsers. But it'll also work in Firefox because Firefox provides the `::-moz-range-progress` pseudo-class ===
 *
 * more info. in the details view
 *
 */

input[type="range"] {
    font-size: 1.5rem;
    width: 12.5em;
}

input[type="range"] {
    color: #535353;
    --thumb-height: 1.2em;
    --track-height: 0.22em;
    --track-color: rgba(0, 0, 0, .15);
    --brightness-hover: 100%;
    --brightness-down: 100%;
    --clip-edges: 0.2em;
}

/* === range commons === */
input[type="range"] {
    position: relative;
    background: #fff0;
    overflow: hidden;
}

input[type="range"]:active {
    cursor: grabbing;
}

input[type="range"]:disabled {
    filter: grayscale(1);
    opacity: 0.3;
    cursor: not-allowed;
}

/* === WebKit specific styles === */
input[type="range"],
input[type="range"]::-webkit-slider-runnable-track,
input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    transition: all ease 100ms;
    height: var(--thumb-height);
}

input[type="range"]::-webkit-slider-runnable-track,
input[type="range"]::-webkit-slider-thumb {
    position: relative;
}

input[type="range"]::-webkit-slider-thumb {
    --thumb-radius: calc((var(--thumb-height) * 0.5) - 1px);
    --clip-top: calc((var(--thumb-height) - var(--track-height)) * 0.5 - 0.5px);
    --clip-bottom: calc(var(--thumb-height) - var(--clip-top));
    --clip-further: calc(100% + 1px);
    --box-fill: calc(-100vmax - var(--thumb-width, var(--thumb-height))) 0 0 100vmax currentColor;

    width: var(--thumb-width, var(--thumb-height));
    background: linear-gradient(currentColor 0 0) scroll no-repeat left center / 50% calc(var(--track-height) + 1px);
    background-color: currentColor;
    box-shadow: var(--box-fill);
    border-radius: var(--thumb-width, var(--thumb-height));

    filter: brightness(100%);
    clip-path: polygon(100% -1px,
            var(--clip-edges) -1px,
            0 var(--clip-top),
            -100vmax var(--clip-top),
            -100vmax var(--clip-bottom),
            0 var(--clip-bottom),
            var(--clip-edges) 100%,
            var(--clip-further) var(--clip-further));
}

input[type="range"]:hover::-webkit-slider-thumb {
    filter: brightness(var(--brightness-hover));
    cursor: grab;
}

input[type="range"]:active::-webkit-slider-thumb {
    filter: brightness(var(--brightness-down));
    cursor: grabbing;
}

input[type="range"]::-webkit-slider-runnable-track {
    background: linear-gradient(var(--track-color) 0 0) scroll no-repeat center / 100% calc(var(--track-height) + 1px);
}

input[type="range"]:disabled::-webkit-slider-thumb {
    cursor: not-allowed;
}

/* === Firefox specific styles === */
input[type="range"],
input[type="range"]::-moz-range-track,
input[type="range"]::-moz-range-thumb {
    appearance: none;
    transition: all ease 100ms;
    height: var(--thumb-height);
}

input[type="range"]::-moz-range-track,
input[type="range"]::-moz-range-thumb,
input[type="range"]::-moz-range-progress {
    background: #fff0;
}

input[type="range"]::-moz-range-thumb {
    background: currentColor;
    border: 0;
    width: var(--thumb-width, var(--thumb-height));
    border-radius: var(--thumb-width, var(--thumb-height));
    cursor: grab;
}

input[type="range"]:active::-moz-range-thumb {
    cursor: grabbing;
}

input[type="range"]::-moz-range-track {
    width: 100%;
    background: var(--track-color);
}

input[type="range"]::-moz-range-progress {
    appearance: none;
    background: currentColor;
    transition-delay: 30ms;
}

input[type="range"]::-moz-range-track,
input[type="range"]::-moz-range-progress {
    height: calc(var(--track-height) + 1px);
    border-radius: var(--track-height);
}

input[type="range"]::-moz-range-thumb,
input[type="range"]::-moz-range-progress {
    filter: brightness(100%);
}

input[type="range"]:hover::-moz-range-thumb,
input[type="range"]:hover::-moz-range-progress {
    filter: brightness(var(--brightness-hover));
}

input[type="range"]:active::-moz-range-thumb,
input[type="range"]:active::-moz-range-progress {
    filter: brightness(var(--brightness-down));
}

input[type="range"]:disabled::-moz-range-thumb {
    cursor: not-allowed;
}