:root {
  --bg: #0b0f14;
  --panel: #111826;
  --text: #e9eef5;
  --muted: #9aa7b2;
  --accent: #7fd3ff;
  --border: #1b2a3a;
}
* { box-sizing: border-box; }
body {
  margin: 0;
  font-family: ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial;
  background: radial-gradient(1200px 800px at 20% -10%, #172335 0%, #0b0f14 50%);
  color: var(--text);
}
.layout { display: grid; grid-template-columns: 240px 1fr; min-height: 100vh; }
.sidebar {
  background: #0a0f16; border-right: 1px solid var(--border); padding: 18px 14px; position: sticky; top: 0; height: 100vh;
}
.viewer {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
}
.viewer-toolbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin-bottom: 10px;
}
.viewer-toolbar a {
  color: var(--accent);
  text-decoration: none;
  font-size: 12px;
}
.viewer-frame {
  width: 100%;
  min-height: 72vh;
  border: 1px solid var(--border);
  border-radius: 12px;
  background: #0c121c;
}
.sidebar h1 { margin: 0 0 8px; font-size: 18px; }
.sidebar .muted { color: var(--muted); font-size: 12px; margin-bottom: 12px; }
.nav-group { font-size: 11px; letter-spacing: .1em; text-transform: uppercase; color: #5f6c78; margin: 16px 10px 6px; }
.nav a { display: block; text-decoration: none; color: var(--muted); font-size: 13px; padding: 8px 10px; border-radius: 10px; }
.nav a:hover, .nav a.active { background: #121a26; color: var(--text); }
.content { padding: 24px; }
.card {
  background: linear-gradient(180deg, #131c2a 0%, #0f1722 100%);
  border: 1px solid var(--border); border-radius: 14px; padding: 18px;
  box-shadow: 0 10px 30px rgba(0,0,0,0.25); margin-bottom: 18px;
}
.card h2 { margin: 0 0 10px; font-size: 18px; }
.grid { display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.stat { background: #0c121c; border: 1px solid var(--border); border-radius: 10px; padding: 12px; }
.stat h3 { margin: 0 0 6px; font-size: 14px; }
.stat p { margin: 0; font-size: 12px; color: var(--muted); }
.list { list-style: none; padding: 0; margin: 0; display: grid; gap: 8px; }
.list a { color: var(--accent); text-decoration: none; font-size: 13px; }
.notice { font-size: 12px; color: var(--muted); }
@media (max-width: 960px) {
  .layout { grid-template-columns: 1fr; }
  .sidebar { position: relative; height: auto; }
  .viewer-frame { min-height: 60vh; }
}

@media (max-width: 640px) {
  .viewer-frame { min-height: 55vh; }
}