body {
  margin: 0;
  font-family: 'Inter', sans-serif;
  background: #f9fafb;
  color: #111;
}

.app-container {
  display: flex;
  height: 100vh;
}

/* Sidebar */
.sidebar {
  width: 250px;
  background: #1f2937;
  color: #f9fafb;
  padding: 1rem;
  display: flex;
  flex-direction: column;
}

.sidebar h2 {
  margin-bottom: 1rem;
}

.sidebar h3 {
  margin-top: 2rem;
  font-size: 1rem;
  border-top: 1px solid #374151;
  padding-top: 0.5rem;
}

.btn {
  background: #374151;
  color: #f9fafb;
  border: none;
  padding: 0.5rem;
  margin-bottom: 0.5rem;
  cursor: pointer;
  border-radius: 4px;
}

.btn-green {
  background: #10b981;
}

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

.contents-list li {
  margin: 0.25rem 0;
  font-size: 0.9rem;
}

/* Editor */
.editor {
  flex: 1;
  padding: 2rem;
  background: #fff;
  overflow-y: auto;
  text-align: center;
  font-family: 'Roboto Mono', monospace;
}