:root {
  --bg: #ffffff;
  --fg: #222;
  --sidebar: #f4f4f4;
  --accent: #0066cc;
}

[data-theme="dark"] {
  --bg: #121212;
  --fg: #eaeaea;
  --sidebar: #1e1e1e;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: system-ui, sans-serif;
  background: var(--bg);
  color: var(--fg);
  height: 100vh;
}

header {
  display: flex;
  justify-content: space-between;
  padding: 6px 12px;
  border-bottom: 1px solid #ccc;
}

.container {
  display: flex;
  height: calc(100vh - 42px);
}

.sidebar {
  width: 260px;
  background: var(--sidebar);
  overflow-y: auto;
  padding: 10px;
}

.sidebar a {
  display: block;
  padding: 6px;
  text-decoration: none;
  color: var(--fg);
  border-radius: 4px;
}

.sidebar a.active {
  background: var(--accent);
  color: white;
}

.content {
  flex: 1;
}

iframe {
  width: 100%;
  height: 100%;
  border: none;
}

/* Print */
@media print {
  header, .sidebar {
    display: none;
  }
  iframe {
    height: auto;
  }
}