<button type="button" data-dl>
	<span class="dl-icon"></span><span>&#x44;&#x6F;&#x77;&#x6E;&#x6C;&#x6F;&#x61;&#x64;</span>
</button>

* {
	border: 0;
	box-sizing: border-box;
	margin: 0;
	padding: 0;
}
:root {
	--dur: 3s;
	--arrowA: polygon(33% 0%,67% 0%,67% 60%,100% 60%,50% 100%,0% 60%,33% 60%);
	--arrowB: polygon(0% 37.5%,100% 37.5%,100% 62.5%,100% 62.5%,50% 62.5%,0% 62.5%,0% 62.5%);
	font-size: calc(20px + (40 - 20)*(100vw - 320px)/(2560 - 320));
}
body, button {
	display: flex;
	font: 1em/1.5 Hind, sans-serif;
}
body {
	background: #e3e4e8;
	height: 100vh;
	overflow: hidden;
}
button {
	background: #255ff4;
	border-radius: 0.2em;
	color: #fff;
	cursor: pointer;
	display: flex;
	margin: auto;
	padding: 0.5em 1em;
	position: relative;
	transition: background 0.15s linear;
	width: 10.5em;
	-webkit-appearance: none;
	-moz-appearance: none;
	appearance: none;
	-webkit-tap-highlight-color: transparent;
}
button:focus {
	outline: transparent;
}
button::-moz-focus-inner {
	border: 0;
}
button:not(:disabled):focus, button:not(:disabled):hover {
	background: #0b46da;
}
button:not(:disabled):active {
	transform: translateY(1px);
}
button:disabled {
	cursor: not-allowed;
}
button span, button:before, button:after {
	display: inline-block;
	pointer-events: none;
}
button:before, button:after {
	border-radius: 0.25em;
	opacity: 0;
	top: 1em;
	left: 1.3em;
	height: 0.5em;
	transform-origin: 0.25em 50%;
	z-index: 2;
}
button:before {
	transform: rotate(-180deg);
	width: 0.8em;
}
button:after {
	width: 1.2em;
}
button:before, button:after, .dl-icon:before, .dl-icon:after {
	content: "";
	display: block;
	position: absolute;
}
button:before, button:after, .dl-icon:before {
	background: currentColor;
}
button span + span {
	margin: auto;
}
.dl-icon {
	margin-right: 0.5em;
	position: relative;
	width: 1.5em;
	height: 1.5em;
}
.dl-icon:before {
	clip-path: var(--arrowA);
	-webkit-clip-path: var(--arrowA);
	top: 0;
	left: calc(50% - 0.55em);
	transform-origin: 50% 100%;
	width: 1.1em;
	height: 1em;
	z-index: 1;
}
.dl-icon:after {
	background-image: linear-gradient(#0b46da,#0b46da);
	background-position: -1.5em 0;
	background-size: 100% 100%;
	background-repeat: no-repeat;
	box-shadow:
		0.25em 0 0 inset,
		-0.25em 0 0 inset,
		0 -0.25em 0 inset;
	bottom: 0;
	width: 100%;
	height: 0.5em;
}
.dl-working:before {
	animation: checkOutA var(--dur) linear forwards;
}
.dl-working:after {
	animation: checkOutB var(--dur) linear forwards;
}
.dl-working .dl-icon {
	animation: impact var(--dur) linear forwards;
}
.dl-working .dl-icon:before {
	animation: arrowToBar var(--dur) linear forwards;
}
.dl-working .dl-icon:after {
	animation: trayToBar var(--dur) linear forwards;
}

/* Animation */
@keyframes impact {
	from, 15% {
		transform: translateY(0);
	}
	17.5% {
		transform: translateY(0.25em);
	}
	20%, to {
		transform: translateY(0);
	}
}
@keyframes arrowToBar {
	from {
		clip-path: var(--arrowA);
		-webkit-clip-path: var(--arrowA);
	}
	10% {
		clip-path: var(--arrowB);
		-webkit-clip-path: var(--arrowB);
		transform: translateY(0);
	}
	15% {
		clip-path: var(--arrowB);
		-webkit-clip-path: var(--arrowB);
		transform: translateY(0.625em);
	}
	30% {
		clip-path: var(--arrowB);
		-webkit-clip-path: var(--arrowB);
		opacity: 1;
		transform: translateY(0.125em);
	}
	35%, to {
		clip-path: var(--arrowB);
		-webkit-clip-path: var(--arrowB);
		opacity: 0;
		transform: translateY(0.125em);
	}
}
@keyframes trayToBar {
	from, 15% {
		background-color: transparent;
		border-radius: 0;
		box-shadow:
			0.25em 0 0 inset,
			-0.25em 0 0 inset,
			0 -0.25em 0 inset;
		transform: translateY(0);
	}
	15.1% {
		background-color: currentColor;
		border-radius: 0;
		box-shadow:
			0 0 0 inset,
			0 0 0 inset,
			0 0 0 0.1em inset;
		transform: translateY(0);
	}
	30% {
		background-color: currentColor;
		background-position: -1.5em 0;
		border-radius: 0.25em;
		box-shadow:
			0 0 0 inset,
			0 0 0 inset,
			0 0 0 0.1em inset;
		transform: translateY(-0.5em);
	}
	90% {
		background-color: currentColor;
		background-position: 0 0;
		border-radius: 0.25em;
		box-shadow:
			0 0 0 inset,
			0 0 0 inset,
			0 0 0 0.1em inset;
		opacity: 1;
		transform: translateY(-0.5em);
	}
	90.1%, to {
		background-color: currentColor;
		background-position: 0 0;
		border-radius: 0.25em;
		box-shadow:
			0 0 0 inset,
			0 0 0 inset,
			0 0 0 0.1em inset;
		opacity: 0;
		transform: translateY(-0.5em);
	}
}
@keyframes checkOutA {
	from, 90% {
		opacity: 0;
		transform: translate(0,0) rotate(-180deg);
	}
	90.1% {
		opacity: 1;
		width: 0.8em;
		transform: translate(0,0) rotate(-180deg);
	}
	92.5% {
		opacity: 1;
		width: 1em;
		transform: translate(0,0.5em) rotate(-120deg);
	}
	95%, to {
		opacity: 1;
		width: 1em;
		transform: translate(0,0.375em) rotate(-135deg);
	}
}
@keyframes checkOutB {
	from, 90% {
		opacity: 0;
		transform: translate(0,0) rotate(0);
	}
	90.1% {
		opacity: 1;
		width: 1.2em;
		transform: translate(0,0) rotate(0);
	}
	92.5% {
		opacity: 1;
		width: 1.6em;
		transform: translate(0,0.5em) rotate(-60deg);
	}
	95%, to {
		opacity: 1;
		width: 1.6em;
		transform: translate(0,0.375em) rotate(-45deg);
	}
}

/* Dark mode */
@media (prefers-color-scheme: dark) {
	body {
		background: #2e3138;
	}
}

document.addEventListener("DOMContentLoaded",function(){
	this.addEventListener("click",e => {
		let tar = e.target;
		if (tar.hasAttribute("data-dl")) {
			let dlClass = "dl-working";
			if (!tar.classList.contains(dlClass)) {
				let lastSpan = tar.querySelector("span:last-child"),
					lastSpanText = lastSpan.textContent,
					timeout = getMSFromProperty("--dur",":root");

				tar.classList.add(dlClass);
				lastSpan.textContent = "Downloading…";
				tar.disabled = true;

				setTimeout(() => {
					lastSpan.textContent = "Completed!";
				},timeout * 0.9);

				setTimeout(() => {
					tar.classList.remove(dlClass);
					lastSpan.textContent = lastSpanText;
					tar.disabled = false;
				},timeout + 1e3);
			}
		}
	});
});
function getMSFromProperty(property,selector) {
	let cs = window.getComputedStyle(document.querySelector(selector)),
		transDur = cs.getPropertyValue(property),
		msLabelPos = transDur.indexOf("ms"),
		sLabelPos = transDur.indexOf("s");

	if (msLabelPos > -1)
		return transDur.substr(0,msLabelPos);
	else if (sLabelPos > -1)
		return transDur.substr(0,sLabelPos) * 1e3;
}