HTMLify

*,
*:after,
*:before {
    box-sizing: border-box;
}

:root {
    --transition: 0.25s;
    --spark: 1.8s;
    --hue: 245;
}

body {
    --active: 0;
    background: hsl(var(--hue) calc(var(--active) * 97%) 6%);
    display: grid;
    place-items: center;
    min-height: 100vh;
    font-family: system-ui, sans-serif;
    transition: background var(--transition);
    overflow: hidden;
}

button {
    --cut: 0.1em;
    --active: 0;
    --bg:
        radial-gradient(120% 120% at 126% 126%,
            hsl(var(--hue) calc(var(--active) * 97%) 98% / calc(var(--active) * 0.9)) 40%,
            transparent 50%) calc(100px - (var(--active) * 100px)) 0 / 100% 100% no-repeat,
        radial-gradient(120% 120% at 120% 120%,
            hsl(var(--hue) calc(var(--active) * 97%) 70% / calc(var(--active) * 1)) 30%,
            transparent 70%) calc(100px - (var(--active) * 100px)) 0 / 100% 100% no-repeat,
        hsl(var(--hue) calc(var(--active) * 100%) calc(12% - (var(--active) * 8%)));
    background: var(--bg);
    font-size: 2rem;
    font-weight: 500;
    border: 0;
    cursor: pointer;
    padding: 0.9em 1.3em;
    display: flex;
    align-items: center;
    gap: 0.25em;
    white-space: nowrap;
    border-radius: 2rem;
    position: relative;
    box-shadow:
        0 0 calc(var(--active) * 6em) calc(var(--active) * 3em) hsl(var(--hue) 97% 61% / 0.5),
        0 0.05em 0 0 hsl(var(--hue) calc(var(--active) * 97%) calc((var(--active) * 50%) + 30%)) inset,
        0 -0.05em 0 0 hsl(var(--hue) calc(var(--active) * 97%) calc(var(--active) * 10%)) inset;
    transition: box-shadow var(--transition), scale var(--transition), background var(--transition);
    scale: calc(1 + (var(--active) * 0.1));
    transform-style: preserve-3d;
    perspective: 100vmin;
    overflow: hidden;
}

button:active {
    scale: 1;
}

.star {
    height: calc(var(--size) * 1px);
    aspect-ratio: 1;
    background: white;
    border-radius: 50%;
    /*	filter: blur(4px);*/
    position: absolute;
    opacity: var(--alpha);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) rotate(10deg) rotate(0deg) translateY(calc(var(--distance) * 1px));
    animation: orbit calc(var(--duration) * 1s) calc(var(--delay) * -1s) infinite linear;
}

@keyframes orbit {
    to {
        transform: translate(-50%, -50%) rotate(10deg) rotate(360deg) translateY(calc(var(--distance) * 1px));
    }
}

.galaxy {
    position: absolute;
    width: 100%;
    aspect-ratio: 1;
    top: 50%;
    left: 50%;
    translate: -50% -50%;
    overflow: hidden;
    opacity: var(--active);
    transition: opacity var(--transition);
    /*transform-style: preserve-3d;
	perspective: 100vmin;*/
    /*	opacity: 0.25;*/
}

.galaxy__ring {
    height: 200%;
    width: 200%;
    position: absolute;
    top: 50%;
    left: 50%;
    border-radius: 50%;
    transform: translate(-28%, -40%) rotateX(-24deg) rotateY(-30deg) rotateX(90deg);
    transform-style: preserve-3d;
    /*	background: red;*/
}

.galaxy__container {
    position: absolute;
    inset: 0;
    opacity: var(--active);
    transition: opacity var(--transition);
    mask: radial-gradient(white, transparent);
}

.star--static {
    animation: none;
    top: 50%;
    left: 50%;
    transform: translate(0, 0);
    max-height: 4px;
    filter: brightness(4);
    opacity: 0.9;
    animation:
        move-x calc(var(--duration) * 0.1s) calc(var(--delay) * -0.1s) infinite linear,
        move-y calc(var(--duration) * 0.2s) calc(var(--delay) * -0.2s) infinite linear;
}

button:hover .star--static {
    animation-play-state: paused;
}

@keyframes move-x {
    0% {
        translate: -100px 0;
    }

    100% {
        translate: 100px 0;
    }
}

@keyframes move-y {
    0% {
        transform: translate(0, -50px);
    }

    100% {
        transform: translate(0, 50px);
    }
}

.spark {
    position: absolute;
    inset: 0;
    border-radius: 2rem;
    rotate: 0deg;
    overflow: hidden;
    mask: linear-gradient(white, transparent 50%);
    animation: flip calc(var(--spark) * 2) infinite steps(2, end);
}

@keyframes flip {
    to {
        rotate: 360deg;
    }
}

.spark:before {
    content: "";
    position: absolute;
    width: 200%;
    aspect-ratio: 1;
    top: 0%;
    left: 50%;
    z-index: -1;
    translate: -50% -15%;
    rotate: 0;
    transform: rotate(-90deg);
    opacity: calc((var(--active)) + 0.4);
    background: conic-gradient(from 0deg,
            transparent 0 340deg,
            white 360deg);
    transition: opacity var(--transition);
    animation: rotate var(--spark) linear infinite both;
}

.spark:after {
    content: "";
    position: absolute;
    inset: var(--cut);
    border-radius: 2rem;
}

.backdrop {
    position: absolute;
    inset: var(--cut);
    background: var(--bg);
    border-radius: 2rem;
    transition: background var(--transition);
}

@keyframes rotate {
    to {
        transform: rotate(90deg);
    }
}



@supports(selector(:has(:is(+ *)))) {
    body:has(button:is(:hover, :focus-visible)) {
        --active: 1;
        --play-state: running;
    }

    .bodydrop {
        display: none;
    }
}

button:is(:hover, :focus-visible)~ :is(.bodydrop, .particle-pen) {
    --active: 1;
    --play-state: running;
}

.bodydrop {
    background: hsl(260 calc(var(--active) * 97%) 6%);
    position: fixed;
    inset: 0;
    z-index: -1
}



button:is(:hover, :focus-visible) {
    --active: 1;
    --play-state: running;
}


.galaxy-button {
    position: relative;
}

@keyframes float-out {
    to {
        rotate: 360deg;
    }
}

.text {
    translate: 2% -6%;
    letter-spacing: 0.01ch;
    /*background: linear-gradient(90deg, hsl(0 0% calc((var(--active) * 100%) + 65%)), hsl(0 0% calc((var(--active) * 100%) + 26%)));
	-webkit-background-clip: text;*/
    color: hsl(0 0% calc(60% + (var(--active) * 26%)));
}

button svg {
    inline-size: 1.25em;
    translate: -25% -5%;
}