Slider Feature using flutter - flutter

Question

I tried to recreate the sliding image feature on the website superlist.com using html and I found a tutorial that made it work.
HTML
<div id="left-side" class="side">
<h2 class="title">
Sometimes a simple header is
<span class="fancy">better</span>
</h2>
</div>
<div id="right-side" class="side">
<h2 class="title">
Sometimes a simple header is
<span class="fancy">better</span>
</h2>
</div>
<a id="source-link" class="meta-link" href="https://superlist.com" target="_blank">
<i class="fa-solid fa-link"></i>
<span class="roboto-mono">Source</span>
</a>
<a id="yt-link" class="meta-link" href="https://youtu.be/zGKNMm4L-r4" target="_blank">
<i class="fa-brands fa-youtube"></i>
<span>2 min tutorial</span>
</a>
CSS
:root {
--yellow: rgb(253, 216, 53);
--blue: rgb(98, 0, 234);
--dark: rgb(20, 20, 20);
}
body {
background-color: var(--dark);
margin: 0px;
}
.side {
display: grid;
height: 100vh;
overflow: hidden;
place-items: center;
position: absolute;
width: 100%;
}
.side .title {
font-family: "Rubik", sans-serif;
font-size: 8vw;
margin: 0px 10vw;
width: 80vw;
}
.side .fancy {
font-family: "Lobster", cursive;
font-size: 1.3em;
line-height: 0.8em;
}
#left-side {
background-color: var(--blue);
width: 60%;
z-index: 2;
}
#left-side .title {
color: white;
}
#left-side .fancy {
color: var(--yellow);
}
#right-side {
background-color: var(--yellow);
}
#right-side .title {
color: var(--dark);
}
#right-side .fancy {
color: white;
}
/* -- YouTube Link Styles -- */
#source-link {
top: 60px;
}
#source-link > i {
color: rgb(94, 106, 210);
}
#yt-link {
top: 10px;
}
#yt-link > i {
color: rgb(239, 83, 80);
}
.meta-link {
align-items: center;
backdrop-filter: blur(3px);
background-color: rgba(40, 40, 40, 0.9);
border-radius: 6px;
box-shadow: 2px 2px 2px rgba(0, 0, 0, 0.1);
cursor: pointer;
display: inline-flex;
gap: 5px;
left: 10px;
padding: 10px 20px;
position: fixed;
text-decoration: none;
transition: background-color 350ms, border-color 350ms;
z-index: 10000;
}
.meta-link:hover {
background-color: rgb(40, 40, 40);
}
.meta-link > i, .meta-link > span {
height: 20px;
line-height: 20px;
}
.meta-link > span {
color: white;
font-family: "Rubik", sans-serif;
transition: color 600ms;
}
JS
const left = document.getElementById("left-side");
const handleMove = e => {
left.style.width = `${e.clientX / window.innerWidth * 100}%`;
}
document.onmousemove = e => handleMove(e);
document.ontouchmove = e => handleMove(e.touches[0]);
I used the code and it worked fine but I was wondering whether you could do the same using flutter. I tried searching for specific widgets that allow you to make this kind of slider, but until now I haven't found anything satisfying, so I'm guessing you'd need a custom solution here.
How can I make this feature possible using flutter?
https://drive.google.com/file/d/1_FxXK2Ymo1GLRRIiNzmfIt95-DsYy1O2/view?usp=sharing
you can see a UI example above