JSFiddle - React, Tailwind, and code Playground

HTML

<div class="box">
    <a href="#">sdfsdf</a>
</div>
<div class="fixed">
    <div class="a">1</div>
    <div class="b">2</div>
    <div class="c">3</div>
</div>

CSS

body {margin: 0;padding:0;}
.box {
    width: 300px;
    height: 2000px;
    background: red;
    margin: 0 auto;
    padding-left: 55px;
    box-sizing: border-box;
}
.fixed {
    position: fixed;
    width: 50%;
    height: 200px;
    left:0;
    top:0;
    background: blue;
    margin-left: -100px;
}
.a,
.b,
.c {
    position: absolute;
    width: 50px;
    height: 50px;
    right:0;
   
}
.a {
    top:0;
    background: green;
}
.b {
    top:60px;
    background: green;
}
.c {
    top:120px;
    background: green;
}