JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
    <div class="a"></div>
    <div class="b"></div>
    <div class="c"></div>
</div>

CSS

.container{
    background-color: red;
    width: 90%;
    margin: 0 auto;
    height: 200px;
    overflow-y: scroll;    
}

.a{
   background-color: yellow;
   height: 30px;  
   margin: 2px;   
   width:90%;
   position:fixed;    
}

.b{
   background-color: blue;
   height: 30px; 
   margin: 2px;    
   width:90%;
   position:fixed;
   top:30px;
}

.c{
   background-color: transparent;
   height: 250px; 
   margin: 2px;   
}