body {
  display: flex;
  font-family: sans-serif;
}

#sidebar {
  width: 250px;
  border-right: 1px solid #ccc;
  padding: 10px;
}

#file-list .item {
  padding: 5px;
  cursor: pointer;
}

#file-list .item:hover {
  background: #eee;
}

#main {
  flex: 1;
  padding: 10px;
}