JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>

  <head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width,initial-scale=1">
    <title>title</title>
  </head>

  <body>
    <div class="sidebar">
      <div class="sidebar__profile">
        <img src="http://chittagongit.com//images/avatar-icon/avatar-icon-4.jpg" height=50px alt="image" class="sidebar__profile__avatar" />
        <div class="sidebar__profile__name">User Name</div>
      </div>
      <nav>
        <div class="sidebar__menuitem">
          <div>Menu Item 1</div>
          <div class="count">2</div>
        </div>
        <div class="sidebar__menuitem">
          <div>Menu Item 2</div>
          <div class="count">2</div>
        </div>
        <div class="sidebar__menuitem">
          <div>Menu Item 3</div>
          <div class="count">2</div>
        </div>
        <div class="sidebar__menuitem">
          <div>Menu Item 4</div>
          <div class="count">2</div>
        </div>
        <div class="sidebar__menuitem">
          <div>Menu Item 5</div>
          <div class="count">2</div>
        </div>
        <div class="sidebar__menuitem">
          <div>Menu Item 6</div>
          <div class="count">2</div>
        </div>
        <div class="sidebar__menuitem">
          <div>Menu Item 7</div>
          <div class="count">2</div>
        </div>
      </nav>
    </div>
  </body>

</html>

CSS

nav {
  overflow: auto;
}

.sidebar__profile {
  align-self: center;
  flex-shrink: 0;
  padding: 16px;
}

html {
  background-color: #141E30;
  margin: 0;
  padding: 0;
}

.sidebar {
  display: flex;
  flex-direction: column;
  width: 300px;
  top: 0;
  bottom: 0;
  position: fixed;
  overflow: auto;
  background: #0a0c0f;
  color: #EAE9E9;
}

.sidebar__menuitem {
  padding-bottom: 10px;
  display: flex;
  align-items: center;
  flex-shrink: 0;
  height: 30px;
}

.count {
  margin-left: auto;
  margin-right: 20px;
  border-radius: 6px;
  padding: 2px 5px;
  background-color: #EAE9E9;
  color: #0a0c0f;
}