/* Simple two‑pane layout */
html, body {
  height: 100%;
  margin: 0;
  font-family: Arial, Helvetica, sans-serif;
}
#container {
  display: flex;
  height: 100%;
}
#tree {
  width: 250px;
  overflow-y: auto;
  border-right: 1px solid #ddd;
  background: #f9f9f9;
  padding: 10px;
}
#content {
  flex: 1;
  overflow-y: auto;
  padding: 20px;
}
ul {
  list-style: none;
  padding-left: 1em;
}
li {
  cursor: pointer;
  margin: 2px 0;
}
li.dir > span::before {
  content: "📁 ";
}
li.file > span::before {
  content: "📄 ";
}
li span:hover {
  background: #e0e0e0;
}