:root {
  --bg: #ffffff;
  --surface: #f7f8fa;
  --ink: #1a1d24;
  --muted: #5c6570;
  --border: #e2e6ec;
  --accent: #1f6feb;
  --alert: #b42318;
}
* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
.topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 1.5rem;
  border-bottom: 1px solid var(--border);
}
.brand-mark { font-weight: 700; letter-spacing: 0.12em; margin-right: 0.75rem; }
.brand-sub { color: var(--muted); font-size: 0.85rem; }
.pill {
  font-size: 0.75rem;
  padding: 0.25rem 0.65rem;
  border-radius: 999px;
  background: var(--surface);
  border: 1px solid var(--border);
}
.layout {
  display: grid;
  grid-template-columns: 280px 340px 1fr;
  flex: 1;
  min-height: 0;
}
.panel {
  border-right: 1px solid var(--border);
  padding: 1.25rem;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}
.panel h2 { font-size: 0.9rem; text-transform: uppercase; letter-spacing: 0.06em; color: var(--muted); }
.list { display: flex; flex-direction: column; gap: 0.5rem; }
.item {
  padding: 0.65rem 0.8rem;
  border: 1px solid var(--border);
  border-radius: 0.5rem;
  background: var(--bg);
  cursor: pointer;
  text-align: left;
  font-size: 0.85rem;
}
.item:hover { background: var(--surface); }
.paper {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 0.75rem;
  padding: 1.5rem;
  white-space: pre-wrap;
  line-height: 1.6;
  font-size: 0.92rem;
}