JSFiddle - React, Tailwind, and code Playground

HTML

<div class="App">
   <div class="fs-header-row">
      <p>This is just the replica of a header row</p>
   </div>
   <div class="main-fs-container">
      <aside class="fs-sidebar-left">
         <div class="ks-first-row d-flex justify-content-between align-items-center">
            <h2 class="sidebar-title mb-0">Left SIdebar needs to be stikcy</h2>
         </div>
         <div class="ks-second-row toggle-button-groups">
            <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Iste voluptatem cumque excepturi earum velit id laudantium quod, temporibus minima maiores quam officiis quia numquam. Voluptatem ad minima tempore consequuntur a.</p>
            <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Iste voluptatem cumque excepturi earum velit id laudantium quod, temporibus minima maiores quam officiis quia numquam. Voluptatem ad minima tempore consequuntur a.</p>
            <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Iste voluptatem cumque excepturi earum velit id laudantium quod, temporibus minima maiores quam officiis quia numquam. Voluptatem ad minima tempore consequuntur a.</p>
            <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Iste voluptatem cumque excepturi earum velit id laudantium quod, temporibus minima maiores quam officiis quia numquam. Voluptatem ad minima tempore consequuntur a.</p>
            <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Iste voluptatem cumque excepturi earum velit id laudantium quod, temporibus minima maiores quam officiis quia numquam. Voluptatem ad minima tempore consequuntur a.</p>
            <p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Iste voluptatem cumque excepturi earum velit id laudantium quod, temporibus minima maiores quam officiis quia numquam. Voluptatem ad minima tempore consequuntur a.</p>
         </div>
      </aside>
      <div class="floor-stack-main">
         <div class="buildings-column">
            <div...

CSS

/** Header Row Starts **/
.fs-header-row {
  background: #ffffff;
  /* height: 61px; */
  box-shadow: 0px 4px 7px rgba(0, 0, 0, 0.05);
  display: grid;
}
/** Header Row Ends **/

.main-fs-container {
  position: relative;
  background-color: lime;
  display: grid;
  grid-template-columns: 279px auto;
}
/** Left Sidebar Starts **/
.fs-sidebar-left {
  width: 279px;
  background-color: yellow;
  padding: 12px 10px 12px 15px;
  backdrop-filter: blur(50px);
  position: sticky;
  top: 0;
}
/** Left Sidebar Ends **/
/** Main Container Starts **/
.building-table-container {
  width: fit-content;
  position: relative;
}
.floor-stack-main {
  /* margin-left: 289px; */
  padding: 14px 14px 100px 30px;
  position: relative;
}

.floor-stack-main .building-title {
  font-weight: 600;
  font-size: 16px;
  line-height: 19px;
  color: #2b2b2b;
  margin-bottom: 10px;
}
/** Main Container Ends **/
/**right column starts**/
.floor-stack-main .unit-detail-right {
  position: absolute;
  /* top: 61px; */
  top: 0;
  right: 0;
  background-color: red;
}
.floor-stack-main .unit-detail-right .unit-detail-wrapper {
  width: 279px;
  background: rgba(255, 255, 255, 0.5);
  backdrop-filter: blur(50px);
  padding: 13px 12px;
}
/** right column ends **/