Code Playground

@charset "UTF-8";
@import url(https://fonts.googleapis.com/css?family=Nunito+Sans:300,400,600,700,800);
*,
:after,
:before {
  box-sizing: border-box;
  padding: 0;
  margin: 0;
}
:root {
    --shimmer-hue-1: 213deg;
    --shimmer-sat-1: 95%;
    --shimmer-lit-1: 91%;
    --shimmer-hue-2: 248deg;
    --shimmer-sat-2: 100%;
    --shimmer-lit-2: 86%;
    --shimmer-hue-3: 293deg;
    --shimmer-sat-3: 78%;
    --shimmer-lit-3: 89%;
    
    --glow-hue: 222deg;
    --shadow-hue: 180deg;
    --spring-easing: linear(
    0, 0.002, 0.01 0.9%, 0.038 1.8%, 0.156, 0.312 5.8%, 0.789 11.1%, 1.015 14.2%,
    1.096, 1.157, 1.199, 1.224 20.3%, 1.231, 1.231, 1.226, 1.214 24.6%,
    1.176 26.9%, 1.057 32.6%, 1.007 35.5%, 0.984, 0.968, 0.956, 0.949 42%,
    0.946 44.1%, 0.95 46.5%, 0.998 57.2%, 1.007, 1.011 63.3%, 1.012 68.3%,
    0.998 84%, 1
  );
    --spring-duration: 1.33s;
}
@property --mask {
    syntax: "<angle>";
    inherits: false;
    initial-value: 33deg;
}

@keyframes spin {
    0% {
        --mask: 0deg;
    }
    100% {
        --mask: 360deg;
    }
}

@keyframes wipe {
    0% {
        mask-position: 200% center;
    }
    100% {
        mask-position: 0% center;
    }
}

@keyframes pulse {
    0%, 90%, 100% {
        opacity: 0;
    }
    20% {
        opacity: 1;
    }
}

@keyframes pulse2 {
    0% {
        opacity: 0;
    }
    8% {
        opacity: 1;
    }
    14% {
        opacity: 0;
    }
    20% {
        opacity: 1;
    }
    100% {
        opacity: 0;
    }
}

@keyframes flicker {
  0% { opacity:0.1; mask-image:none;}
  1% { opacity:1; }
  2% { opacity:0.5; }
  3% { opacity:0.1; }
  4% { opacity:0.7; }
  5% { opacity:1; }
  7% { opacity:0.7; 
    mask-image: linear-gradient(
        90deg, transparent 15%, black 45%, black 55%, transparent 85%
    ); }
  8% { opacity:0.1; }
  10% { opacity:0.4; }
  13% { opacity:1; }
  15% { opacity:0.1;  
    mask-image: linear-gradient(
        45deg, rgba(0,0,0,0.4) 25%, transparent 45%, black 65%, black 90%, transparent 100%
    );}
  17% { opacity:0.8;}
  19% { opacity:0.3; }
  21.5% { opacity:0; }
  23% { opacity:1; }
  39% { opacity:0.7; }
  45% { opacity:0.2; }
  49% { opacity:0.9; }
  52% { opacity:0.7;}
  53.5% { opacity:0.2;  
    mask-image: linear-gradient(
        90deg, black 15%, black 45%, rgba(0,0,0,0.4) 75%, transparent 85%
    );}
  57% { opacity:0.8; }
  63% { opacity:1; }
  75% { opacity:.85; }
  77% { opacity:1; }
  80% { opacity:.9; }
  82% { opacity:.95; }
  83% { opacity:.85; }
  86% { opacity:1; }
  89% { opacity:.85; }
  91% { opacity:1; }
  92% { opacity:.9; }
  100% { opacity:1; }
}

@keyframes shine {
    0% {
        opacity: 0;
    }
    15% {
        opacity: 1;
    }
    55% {
        opacity: 1;
    }
    100% {
        opacity: 0;
    }
}
@keyframes text {
    0% {
        background-position: 100% center;
    }    
    100% {
        background-position: -100% center;
    }    
}

button {
    width: 100%;
    color: var(--bg);
    font-weight: 600;
    background-image: linear-gradient(
        315deg, 
        hsl(var(--shimmer-hue-1),var(--shimmer-sat-1),var(--shimmer-lit-1)) 0.00%, 
        hsl(var(--shimmer-hue-2),var(--shimmer-sat-2),var(--shimmer-lit-2)) 47%,
        hsl(var(--shimmer-hue-3),var(--shimmer-sat-3),var(--shimmer-lit-3)) 100.00% 
    );
    padding: .8em 1.4em;
    position: relative;
    isolation: isolate;
    box-shadow: 0 2px 3px 1px hsl(var(--glow-hue) 50% 20% / 50%);
    border-radius: 0.66em;
    scale: 1;
    transition: all var(--spring-duration) var(--spring-easing);
}

.shimmer {
    position: absolute;
    inset: -40px;
    border-radius: inherit;
    mix-blend-mode: color-dodge;
    mix-blend-mode: plus-lighter;
    pointer-events: none;
}

.shimmer::before,
.shimmer::after {
    transition: all 0.5s ease;
    opacity: 0;
    content: "";
    border-radius: inherit;
    position: absolute;
    inset: 40px;
}
.shimmer::before {
    box-shadow: 0 0 3px 2px hsl(var(--shimmer-hue-1) 20% 95%),
        0 0 7px 4px hsl(var(--shimmer-hue-1) 20% 80%),
        0 0 13px 8px hsl(var(--shimmer-hue-2) 40% 60%),
        0 0 22px 6px hsl(var(--shimmer-hue-2) 20% 40%);
    z-index: -1;
}
.shimmer::after {
    box-shadow: inset 0 0 0 1px hsl(var(--shimmer-hue-2) 70% 95%),
        inset 0 0 3px 1px hsl(var(--shimmer-hue-2) 100% 80%),
        inset 0 0 9px 1px hsl(var(--shimmer-hue-2) 100% 70%);
    z-index: 2;
}

button .text {
    color: transparent;
    background-clip: text;
    background-color: var(--bg);
    background-image: linear-gradient(120deg, transparent, hsla(var(--shimmer-hue-1),100%,80%,0.66) 40%, hsla(var(--shimmer-hue-2),100%,90%,.9) 50%, transparent 52%);
    background-repeat: no-repeat;
    background-size: 300% 300%;
    background-position: center 200%;
}

button:not([disabled]).textShine .text {
    animation: text 1s ease-in 1;
}

button:not([disabled]).level0 {
    background-color: rgb(216, 217, 235);
    background-image: none;
}
button:not([disabled]).level1 .shimmer::before,
button:not([disabled]).level1 .shimmer::after {
    animation: shine 2s ease-in 1;
}

button:not([disabled]).level2 .shimmer::before,
button:not([disabled]).level2 .shimmer::after {
    opacity: 1;
}
button:not([disabled]).level2 .shimmer {
    mask-image: conic-gradient(
        from var(--mask, 0deg),
        transparent 0%,
        transparent 10%,
        black 36%,
        black 45%,
        transparent 50%,
        transparent 60%,
        black 85%,
        black 95%,
        transparent 100%
    );
    mask-size: cover;
    animation: spin 3s linear infinite both -0.5s;
}
button:not([disabled]).level2[data-effect=wipe] .shimmer {
    mask-image: linear-gradient(
        90deg, transparent 20%, black 88%, transparent 90%
    );
    mask-size: 200% 200%;
    mask-position: center;
    animation: wipe 1.5s linear infinite both -0.5s;
}
button:not([disabled]).level2[data-effect=wipe2] .shimmer {
    mask-image: linear-gradient(
        90deg, transparent 15%, black 45%, black 55%, transparent 85%
    );
    mask-size: 200% 200%;
    mask-position: center;
    animation: wipe 3s linear infinite both -0.5s;
}
button:not([disabled]).level2[data-effect=pulse] .shimmer {
    mask-image: none;
    animation: pulse 3s ease infinite both  -0.5s;
}
button:not([disabled]).level2[data-effect=pulse2] .shimmer {
    mask-image: none;
    animation: pulse2 3s ease infinite both  -0.5s;
}
button:not([disabled]).level2[data-effect=flicker] .shimmer {
    mask-image: none;
    animation: flicker 3.33s ease infinite both  -0.5s;
}

button[disabled] {
    background: rgb(76 76 92);
    background-image: none;
}

button:hover:not(:active):not([disabled]).level1,
button:hover:not(:active):not([disabled]).level2 {
    scale: 1.1;
    transition-duration: calc(var(--spring-duration)*0.5);
}
button:active:not([disabled]).level1,
button:active:not([disabled]).level2  {
    scale: 1.05;
    transition-duration: calc(var(--spring-duration)*0.5);
}

button:hover.level2 .shimmer {
    animation: none!important;
    mask-image: none!important;
}

button:hover:not([disabled]) .shimmer::before,
button:hover:not([disabled]) .shimmer::after,
button.active .shimmer::before,
button.active .shimmer::after {
    opacity: 0.75;
}

body,
html {
    display: block;
    height: 100dvh;
    padding: 20px;
    margin: 0;
    background-image: radial-gradient(
        circle at 50% 0%,
        rgb(67, 54, 74) 16.4%,
        rgb(47, 48, 67) 68.2%,
        rgb(27, 23, 36) 99.1%
    );
}
main#app {
    width: 500px;
    max-width: 100%;
    display: flex;
    gap: 16px;
    flex-direction: column;
    margin: auto;
    padding: 16px;
    align-items: center;
    justify-content: center;
    background: hsla(var(--shadow-hue), 20%, 10%, 0.75);
    border-radius: 16px;
    box-sizing: border-box;
}

.input {
    min-height: 100px;
    width: 100%;
    position: relative;
}
.count {
    position: absolute;
    right: 5px;
    bottom: 5px;
}
textarea {
    min-height: 100px;
    width: 100%;
    background: hsla(0deg,10%,10%,0.5);
    border: 1px solid hsla(0deg,10%,50%,0.5);
    border-radius: 8px;
    color: white;
    padding: 8px;
    box-sizing: border-box;
    font: inherit;
    resize: vertical;
}

.selection {
    margin: 20px auto;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 16px;
}
.selection label {
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

h1 {
    font-size: 1.4rem;
    margin: 0.25em 0;
}

console.log("Event Fired")
// inspired by Aaron Iker
// https://codepen.io/aaroniker/pen/PoOvoaY
// and Adam Argyle
// https://codepen.io/argyleink/details/abPvZJo

// uses custom properties, so will only work in Chromium Browsers.

let levels = [1, 4, 7];

let btn = document.querySelector("button");
let radios = document.querySelectorAll("[type=radio]");
let count = document.querySelector(".count");

let t = document.querySelector("textarea");
let previousWords = wordCount(t.value);
let previousLevel = 0;
let deltaUp = false;

count.innerHTML = levels.at(-1) + 1 -  wordCount(t.value);

function wordCount(str) {
    return str.trim().split(" ").length;
}

t.oninput = (e) => {
    const str = t.value;
    const words = wordCount(str);
    let level = 0;

count.innerHTML = Math.max(levels.at(-1) + 1 - words,0);

btn.classList.add("disabled");
    btn.classList.remove("level0");
    btn.classList.remove("level1");
    btn.classList.remove("level2");
    btn.setAttribute("disabled", true);
    
    addShine = () => {
        if (previousLevel < level) {
            btn.classList.remove("textShine");
            window.requestAnimationFrame(() => {
                btn.classList.add("textShine");
                previousLevel = level;
            });
        } else {
            previousLevel = level;
        }
    }

if (words > levels[2]) {
        level = 3;
        btn.removeAttribute("disabled");
        btn.classList.remove("disabled");
        btn.classList.remove("level0");
        btn.classList.remove("level1");
        btn.classList.add("level2");
        addShine()
    } else if (words > levels[1]) {
        level = 2;
        btn.removeAttribute("disabled");
        btn.classList.remove("disabled");
        btn.classList.remove("level0");
        btn.classList.add("level1");
        addShine()
    } else if (words > levels[0]) {
        level = 1;
        btn.removeAttribute("disabled");
        btn.classList.remove("disabled");
        btn.classList.add("level0");
        addShine()
    } else {
        level = 0;
        btn.setAttribute("disabled", true);
        btn.classList.add("disabled");
        previousLevel = level;
    }

previousWords = words;
};

radios.forEach((r) => {
    r.onchange = (e) => {
        btn.dataset.effect = e.currentTarget.value;
    };
    if( r.checked ) {
        btn.dataset.effect = r.value;
    }
});

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