styles.css

.nav {
  position: sticky;
}

#left {
  position: sticky;
  top: 1em;
  max-height: calc(100vh - 2em);
  height: 100%;
  display: grid;
  grid-template-rows: minmax(0, 1fr) 190px;
}

#users {
  top: 1em;
  overflow-y: auto;
}

.nav {
  top: 0px;
  background-color: white;
  padding: 1em 0;
  margin-top: -1em;
  z-index: 1;
}

.list-group-item, .nav-link {
  cursor: pointer;
}

#users .list-group-item {
  display: flex;
  justify-content: space-between;
}

.user-lang-annotation {
  opacity: 0.4;
}

#keyboard {
  margin: 1em 0 0 1em;
}

#keyboard h5 {
  font-size: 1.1em;
}

#keyboard .key {
  background: #f0f0f0;
  padding: .125em .2em;
  font-family: monospace;
  border-radius: .125em;
  border: 1px solid #b0b0b0;
  margin: .25em;
  line-height: 1;
  display: inline-block;
}


/* X-Small devices (e.g. portrait phones) */
@media (max-width: 576px) {
  #keyboard {
    display: none;
  }

  #left {
    grid-template-rows: unset;
  }

  #users {
    flex-direction: row;
    overflow: scroll;
  }

  .nav {
    margin-top: 0;
    flex-wrap: nowrap;
    overflow: scroll;
  }

  .user-name {
    white-space: nowrap;
  }

  .user-lang {
    display: none;
  }
}

/* Medium Devices */
@media (max-width: 768px) {
  .user-lang-annotation {
    display: none;
  }
}

@media (prefers-color-scheme: dark) {
  body, .nav, .list-group-item {
    background-color: #2d2d2d;
    color: white;
    border-color: rgba(255, 255, 255, .125);
  }

  .key {
    color: black;
  }

  .token {
    background: none !important;
  }

  a {
    color: white !important;
  }
}