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Adding Classes

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About the <head>

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CSS

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CSS Base

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JavaScript

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HTML 

              
                <div class="scroller"></div>
<main>
	<section class="chat">
		<div class="dialog you">
			<figure>
				<img src="https://picsum.photos/id/38/256/256" />
				<p>Scroll to see the chat.</p>
			</figure>
		</div>
		<div class="dialog me">
			<figure>
				<img src="https://picsum.photos/id/39/256/256" />
				<p>Lorem ipsum dolor sit.</p>
			</figure>
		</div>
		<div class="dialog you">
			<figure>
				<img src="https://picsum.photos/id/38/256/256" />
				<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Placeat rerum non quod nulla excepturi.</p>
			</figure>
		</div>
		<div class="dialog me">
			<figure>
				<img src="https://picsum.photos/id/39/256/256" />
				<p>Lorem, ipsum.</p>
			</figure>
		</div>
		<div class="dialog you">
			<figure>
				<img src="https://picsum.photos/id/38/256/256" />
				<p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Cupiditate, ex rem? Sint ratione reprehenderit ut, asperiores incidunt recusandae illo soluta molestiae culpa eius.</p>
			</figure>
		</div>
		<div class="dialog me">
			<figure>
				<img src="https://picsum.photos/id/39/256/256" />
				<p>Lorem ipsum dolor sit amet!</p>
			</figure>
		</div>
		<div class="dialog you">
			<figure>
				<img src="https://picsum.photos/id/38/256/256" />
				<p>Lorem ipsum dolor sit amet.</p>
			</figure>
		</div>
		<div class="dialog me">
			<figure>
				<img src="https://picsum.photos/id/39/256/256" />
				<p>Lorem ipsum dolor sit.</p>
			</figure>
		</div>
		<div class="dialog you">
			<figure>
				<img src="https://picsum.photos/id/38/256/256" />
				<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Placeat rerum non quod nulla excepturi, quam doloremque.</p>
			</figure>
		</div>
		<div class="dialog me">
			<figure>
				<img src="https://picsum.photos/id/39/256/256" />
				<p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Consequatur, harum?</p>
			</figure>
		</div>
		<div class="dialog you">
			<figure>
				<img src="https://picsum.photos/id/38/256/256" />
				<p>Lorem ipsum dolor sit amet, consectetur adipisicing elit.</p>
			</figure>
		</div>
		<div class="dialog me">
			<figure>
				<img src="https://picsum.photos/id/39/256/256" />
				<p>Leave a like if you like this pen! xD</p>
			</figure>
		</div>
	</section>
</main>
!

CSS 

              
                body {
	height: 100vh;
	overflow-x: hidden;
	overflow-y: auto;
	background-color: #333;
}

.scroller {
	width: 100%;
	height: 1000vh;
	overflow-x: hidden;
	position: relative;
	overflow-y: auto;
}

main {
	top: 0;
	position: fixed;
	width: 100%;
	height: 100%;
	transform-style: preserve-3d;
	perspective: 15rem;
	display: flex;
	align-items: center;
	justify-content: center;
	font-size: 2.4rem;
	
	@media only screen and (max-width: 600px) {
		font-size: 1.6rem;
	}
}

.chat {
	padding: 1rem;
	transform-style: preserve-3d;
	transform-origin: bottom center;
	transform: translateY(calc(-50% + 10rem)) translateZ(calc(100vh * var(--phase, 0))) rotateX(90deg);
	// background-color: #333;sa
	height: 100%;
	display: flex;
	flex-direction: column-reverse;
	max-width: 80rem;
	width: 100%;
	margin: 0 auto;
	position: relative;
	
	
	.dialog {
		height: 100%;
		transform: rotateX(-90deg);
		transform-origin: center bottom;
		flex: 1;
		opacity: calc(1 - var(--focal));
		display: flex;
		align-items: flex-end;
		position: relative;
		width: 100%;
		
		figure {
			display: flex;
			align-items: flex-end;
			position: absolute;
			width: 100%;
			
			img {
				width: 5rem;
				height: 5rem;
				border-radius: 5rem;
				margin-inline-end: 1rem;
				border: solid 1px rgba(0, 0, 0, 0.3);
			}

			p {
				background-color: lightsteelblue;
				padding: 2rem;
				@media only screen and (max-width: 600px) {
					padding: 1rem;
				}
				border-radius: .5rem;
				max-width: 60%;
				border: solid 1px rgba(0, 0, 0, 0.3);
				color: rgba(0, 0, 0, 0.7);
			}
		}
		
		&.me {
			justify-content: flex-end;
			
			img {
				margin-inline-end: 0;
				margin-inline-start: 1rem;
			}
			
			figure {
				flex-direction: row-reverse;
				
				p {
					background-color: palegoldenrod;
				}
			}
		}
	}
}
!

JS 

              
                const chats = [...document.querySelectorAll('.chat .dialog')];

const onScroll = _ => {
	const { scrollTop, scrollHeight, clientHeight } = document.scrollingElement;
	const phase = scrollTop / (scrollHeight - clientHeight);
	document.body.style.setProperty('--phase', phase);
	
	chats.forEach((e, i) => {
		const step = 1 / chats.length;
		const focalPoint = step * (i - 1);
		const focal = Math.min(Math.max(1 - (phase - focalPoint) / step, -1), 1);
		e.style.setProperty('--focal', focal);
		e.style.opacity = Math.min(Math.max(1 + focal * 2, 0), 1);
		
		const dist = (phase - step * i) / step;
		e.style.filter = `blur(${Math.min(Math.abs(dist ** 2 * 0.5), 1.2)}rem)`;
	});
};

window.addEventListener('scroll', onScroll);
onScroll();
!
999px

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