<div class="menu-wrapper">
    <h1 class="menu-title">Mail</h1>
    <ul class="menu">
      <li class="is-selected"><a class="menu__link" href="">Inbox</a></li>
      <li><a class="menu__link" href="">Sent</a></li>
      <li><a class="menu__link" href="">Draft</a></li>
      <li><a class="menu__link" href="">Trash</a></li>
    </ul>

    <ul class="menu">
      <li><a class="menu__link" href="">Login</a></li>
      <li><a class="menu__link" href="">Register</a></li>
    </ul>
  </div>

.menu-wrapper {
  display: grid;
  grid-template-rows: auto 1fr auto;
  gap: 1rem;
  width: 12em;
  height: 100vh;
  overflow: auto;
}









html {
  box-sizing: border-box;
}

html *,
html *::after,
html *::before {
  box-sizing: inherit;  
}

body {
  font-family: tahoma;
  line-height: 1.6;
  color: #404040;
  margin: 0;
  background: #fff;
}


.menu-wrapper {
  padding: 1em;
  background: #56727C;
}

.menu {
  padding: 0;
  margin: 0;
  list-style: none;
}

.menu-title {
  color: #D9E9EF;
  margin: 0;
}

.menu__link {
  display: block;
  font-size: .8em;
  padding: .5em .7em;
  margin: .4em 0;
  color: #D9E9EF;
  text-decoration: none;
  border-radius: 4px;
}

.menu__link:hover,
.is-selected .menu__link {
  background: #415F69;
}