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

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

body {
	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%;
	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);
}

.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;
}

.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 {
	position: fixed;
	inset: 0;
	z-index: -1
}



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


.galaxy-button {
	position: relative;
	flex-grow: 4;
	display: flex;
	justify-content: center;
	align-items: center;
	margin-bottom: 10vw;
}

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

.text {
	translate: 2% -6%;
	letter-spacing: 0.01ch;
	color: hsl(0 0% calc(60% + (var(--active) * 26%)));
}

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