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HTML 

              
                <label for="clipper">Unclip Background</label>
<input type="checkbox" id="clipper" />
<h1>Scroll.</h1>
<section>
  <p>
    One of the most fun CSS animation APIs ever. A magical way to create
    scroll-driven animations without the need to touch JavaScript.
    Animations run off the main thread. And you can choose to use View
    Timelines or Scroll Timelines.
  </p>
  <p>Available Chrome 115+</p>
  <div class="actions">
    <a href="https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_scroll-driven_animations" target="_blank" rel="noreferrer noopener"><span>Read the docs</span><svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="1.5" stroke="currentColor" class="w-6 h-6">
        <path stroke-linecap="round" stroke-linejoin="round" d="M12 6.042A8.967 8.967 0 006 3.75c-1.052 0-2.062.18-3 .512v14.25A8.987 8.987 0 016 18c2.305 0 4.408.867 6 2.292m0-14.25a8.966 8.966 0 016-2.292c1.052 0 2.062.18 3 .512v14.25A8.987 8.987 0 0018 18a8.967 8.967 0 00-6 2.292m0-14.25v14.25" />
      </svg>
    </a>
    <a href="https://drafts.csswg.org/scroll-animations-1/" target="_blank" rel="noreferrer noopener"><span>Read the spec</span><svg xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24" stroke-width="1.5" stroke="currentColor" class="w-6 h-6">
        <path stroke-linecap="round" stroke-linejoin="round" d="M19.5 14.25v-2.625a3.375 3.375 0 00-3.375-3.375h-1.5A1.125 1.125 0 0113.5 7.125v-1.5a3.375 3.375 0 00-3.375-3.375H8.25m0 12.75h7.5m-7.5 3H12M10.5 2.25H5.625c-.621 0-1.125.504-1.125 1.125v17.25c0 .621.504 1.125 1.125 1.125h12.75c.621 0 1.125-.504 1.125-1.125V11.25a9 9 0 00-9-9z" />
      </svg>
    </a>
  </div>
</section>
!

CSS 

              
                :root {
  --accent: 310;
  accent-color: hsl(var(--accent) 90% 60%);
}

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

body {
	display: grid;
	place-items: center;
	min-height: 200vh;
	background: hsl(0 0% 0%);
	color: hsl(0 0% 98%);
	font-family:  "SF Pro Text", "SF Pro Icons", "AOS Icons", "Helvetica Neue", Helvetica, Arial, sans-serif, system-ui;
}

label {
  position: fixed;
  top: 1rem;
  right: 2.5rem;
  z-index: 9999;
}

[type=checkbox] {
  position: fixed;
  top: 1.125rem;
  right: 1rem;
}

section {
	position: fixed;
	top: 0;
	left: 50%;
	display: grid;
	justify-content: start;
	align-content: center;
	translate: -50% 0;
	height: 100vh;
	width: 600px;
	max-width: calc(100% - 4rem);
	gap: 1rem;
}

:is(a, p) {
	margin: 0;
	font-size: 1rem;
	font-weight: 400;
	font-size: clamp(1rem, 0.75vw + 1rem, 1.25rem);
}

.actions {
	display: flex;
	gap: 6ch;
	flex-wrap: wrap;
}

:is(p:nth-of-type(2), a) {
	opacity: 0;
	animation: fade-in both linear;
	animation-timeline: scroll(root);
	animation-range: 75vh 90vh;
}

p:nth-of-type(2) {
	--opacity: 0.65;
}

a {
	display: flex;
	gap: 1ch;
	align-items: center;
	color: hsl(0 0% 98%);
	text-decoration-line: none;
}

a:is(:hover, :focus-visible) {
	text-decoration-line: underline;
	text-decoration-thickness: 0.4ch;
	text-underline-offset: 0.5ch;
}

a svg {
	width: 24px;
	stroke-width: 2;
}

@keyframes fade-in {
	to {
		opacity: var(--opacity, 1);
	}
}

h1 {
  position: fixed;
  margin: 0;
  bottom: 1rem;
  right: 1rem;
}

p:nth-of-type(1) {;
	font-size: clamp(1rem, 3vw + 1rem, 2rem);
	font-weight: 600;
	background: radial-gradient(50% 100% at 50% 100%, hsl(var(--accent, 10) 90% 95%), hsl(var(--accent, 10) 90% 50%), transparent 50%);
	background-size: 400% 600%;
	-webkit-background-clip: text;
	background-position: 50% 0;
	color: transparent;
  opacity: 0;
	animation: move-bg both linear, fade-in both linear;
	animation-timeline: scroll(root);
	animation-range: 0 100vh, 40vh 100vh;
}

@keyframes move-bg {
	to { background-position: 50% 100%; }
}

#clipper:checked ~ section p:first-of-type {
  -webkit-background-clip: unset;
  outline: 4px dashed hsl(0 0% 100%);
}

p:first-of-type {
  transition: all 0.2s;
}
!

JS
!
999px

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