<form>
	<label><input class="pristine" type="checkbox" name="A" checked> <span>Apples</span></label>
	<br>
	<label><input class="pristine" type="checkbox" name="B"> <span>Bananas</span></label>
	<br>
	<label><input class="pristine" type="checkbox" name="C"> <span>Cherries</span></label>
	<br>
	<label><input class="pristine" type="checkbox" name="D"> <span>Oranges</span></label>
</form>
* {
	border: 0;
	box-sizing: border-box;
	margin: 0;
	padding: 0;
}
:root {
	--bg: #e3e4e8;
	--checkBg: #ffffff;
	--checkBorder: #c7cad1;
	--fg: #17181c;
	--fgDim: #5c6270;
	--primary: #255ff4;
	--dur: 0.6s;
	font-size: calc(16px + (24 - 16) * (100vw - 320px) / (1280 - 320));
}
body, input {
	color: var(--fg);
	font: 1em/1.5 system-ui, -apple-system, sans-serif;
}
body {
	background: var(--bg);
	display: grid;
	height: 100vh;
	place-items: center;
}
label, input[type=checkbox] {
	cursor: pointer;
}
label {
	display: inline-flex;
	align-items: center;
	margin-bottom: 0.75em;
	position: relative;
	-webkit-tap-highlight-color: transparent;
}
input[type=checkbox], input[type=checkbox]:before, input[type=checkbox]:after {
	width: 1.5rem;
	height: 1.5rem;
}
input[type=checkbox], input[type=checkbox]:before {
	background: var(--checkBg);
	border-radius: 0.2em;
	box-shadow: 0 0 0 1px var(--checkBorder) inset;
}
input[type=checkbox]:before, input[type=checkbox]:after {
	display: block;
	position: absolute;
	top: 0;
	left: 0;
}
input[type=checkbox] {
	margin-right: 0.75em;
	-webkit-appearance: none;
	appearance: none;
}
input[type=checkbox] + span {
	animation: brighten var(--dur) linear;
}
input[type=checkbox]:before {
	animation: unstrike var(--dur) linear;
	content: "";
	transform-origin: 0 50%;
	z-index: 1;
}
input[type=checkbox]:after {
	color: var(--primary);
	content: "\2713";
	font-size: 1.5em;
	line-height: 1;
	text-align: center;
}
input[type=checkbox]:focus {
	outline: transparent;
}
input[type=checkbox]:focus + span {
	text-decoration: underline;
}
input[type=checkbox]:checked + span {
	animation-name: dim;
	color: var(--fgDim);
}
input[type=checkbox]:checked:before {
	animation-name: strike;
	background: var(--fgDim);
	border-radius: 0;
	box-shadow: 0 0 0 1px var(--fgDim) inset;
	transform: translateX(2.25em) scale(1,0.05);
	width: calc(100% - 2.25em);
}
input[type=checkbox].pristine:before, input[type=checkbox].pristine + span {
	animation: none;
}
/* Dark mode */
@media (prefers-color-scheme: dark) {
	:root {
		--bg: #17181c;
		--checkBg: #2e3138;
		--checkBorder: #454954;
		--fg: #e3e4e8;
		--fgDim: #8f95a3;
		--primary: #5583f6;
	}
}
/* Animations */
@keyframes dim {
	from, 83% {
		color: var(--fg);
	}
	to {
		color: var(--fgDim);
	}
}
@keyframes brighten {
	from {
		color: var(--fgDim);
	}
	17%, to {
		color: var(--fg);
	}
}
@keyframes unstrike {
	from {
		background: var(--fgDim);
		border-radius: 0;
		box-shadow: 0 0 0 1px var(--fgDim) inset;
		transform: translateX(2.25em) scale(1,0.05);
		width: calc(100% - 2.25em);
	}
	14% {
		background: var(--fg);
		border-radius: 0;
		box-shadow: 0 0 0 1px var(--fg) inset;
		transform: translateX(2.25em) scale(1,0.05);
		width: calc(100% - 2.25em);
	}
	29% {
		background: var(--fg);
		border-radius: 0;
		box-shadow: 0 0 0 1px var(--fg) inset;
		transform: translateX(2.75em) scale(1,0.05);
		width: calc(100% - 2.25em);
	}
	43% {
		background: var(--fg);
		border-radius: 0;
		box-shadow: 0 0 0 1px var(--fg) inset;
		transform: translateX(-0.5em) scale(0.75,0.05);
		width: 1.5em;
	}
	57% {
		background: var(--fg);
		border-radius: 0;
		box-shadow: 0 0 0 1px var(--fg) inset;
		transform: translateX(0) scale(1,0.05);
		width: 1.5em;
	}
	71% {
		background: var(--fg);
		border-radius: 0.2em;
		box-shadow: 0 0 0 1px var(--fg) inset;
		transform: translateX(0) scale(1,1.25);
		width: 1.5em;
	}
	86% {
		background: var(--fg);
		border-radius: 0.2em;
		box-shadow: 0 0 0 1px var(--fg) inset;
		transform: translateX(0) scale(1,1);
		width: 1.5em;
	}
	to {
		background: var(--checkBg);
		border-radius: 0.2em;
		box-shadow: 0 0 0 1px var(--checkBorder) inset;
		transform: translateX(0) scale(1,1);
		width: 1.5em;
	}
}
@keyframes strike {
	from {
		background: var(--checkBg);
		border-radius: 0.2em;
		box-shadow: 0 0 0 1px var(--checkBorder) inset;
		transform: translateX(0) scale(1,1);
		width: 1.5em;
	}
	17% {
		background: var(--fg);
		border-radius: 0.2em;
		box-shadow: 0 0 0 1px var(--fg) inset;
		transform: translateX(0) scale(1,1);
		width: 1.5em;
	}
	33% {
		background: var(--fg);
		border-radius: 0;
		box-shadow: 0 0 0 1px var(--fg) inset;
		transform: translateX(0) scale(1,0.05);
		width: 1.5em;
	}
	50% {
		background: var(--fg);
		border-radius: 0;
		box-shadow: 0 0 0 1px var(--fg) inset;
		transform: translateX(-0.5em) scale(1,0.05);
		width: 1.5em;
	}
	67% {
		background: var(--fg);
		border-radius: 0;
		box-shadow: 0 0 0 1px var(--fg) inset;
		transform: translateX(2.25em) scale(1.25,0.05);
		width: calc(100% - 2.25em);
	}
	83% {
		background: var(--fg);
		border-radius: 0;
		box-shadow: 0 0 0 1px var(--fg) inset;
		transform: translateX(2.25em) scale(1,0.05);
		width: calc(100% - 2.25em);
	}
	to {
		background: var(--fgDim);
		border-radius: 0;
		box-shadow: 0 0 0 1px var(--fgDim) inset;
		transform: translateX(2.25em) scale(1,0.05);
		width: calc(100% - 2.25em);
	}
}
document.addEventListener("DOMContentLoaded",function(){
	this.forms[0].addEventListener("change",e => {
		e.target.removeAttribute("class");
	});
});

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