/*
 * 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
 *
 */

 

 
 /* === range theme and appearance === */
 
 input[type="range"] {
     color: #ef233c;
     --thumb-height: 1.125em;
     --track-height: 0.125em;
     --track-color: rgba(0, 0, 0, 0.2);
     --brightness-hover: 180%;
     --brightness-down: 80%;
     --clip-edges: 0.125em;
 }
 
 input[type="range"].win10-thumb {
     color: #2b2d42;
 
     --thumb-height: 1.375em;
     --thumb-width: 0.5em;
     --clip-edges: 0.0125em;
 }
 
 @media (prefers-color-scheme: dark) {
     html {
         background-color: #000;
     }
 
     html::before {
         background: radial-gradient(circle at center, #101112, #000);
     }
 
     input[type="range"] {
         color: #f07167;
         --track-color: rgba(255, 255, 255, 0.1);
     }
 
     input[type="range"].win10-thumb {
         color: #3a86ff;
     }
 }
 
 /* === 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;
 }