* { box-sizing: border-box; }
html, body { height: 100%; margin: 0; }
body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
  line-height: 1.6;
  color: #24292e;
  background-color: #ffffff;
}

/* Layout */
.layout { display: grid; grid-template-columns: 250px 1fr; height: 100vh; }

/* Sidebar theme aligned with create/view */
.sidebar {
  width: 250px;
  background-color: #f6f8fa;
  color: #24292e;
  padding: 12px;
  display: flex;
  flex-direction: column;
  border-right: 1px solid #e1e4e8;
}
.sidebar h1 { font-size: 18px; margin: 0 0 10px; font-weight: 600; }
.sidebar nav { display: flex; flex-direction: column; gap: 8px; }

/* Tab buttons styled like sidebar links */
.tab {
  appearance: none;
  display: block;
  width: 100%;
  text-align: left;
  padding: 10px 14px;
  font-size: 14px;
  color: #24292e;
  background: #ffffff;
  border: 1px solid #e1e4e8;
  border-radius: 6px;
  cursor: pointer;
  transition: background 0.2s, color 0.2s, border-color 0.2s;
}
.tab:hover { background: #f3f4f6; color: #0366d6; }
.tab.active { background: #f1f8ff; color: #0366d6; border-color: #c8e1ff; }

/* Content */
.content { position: relative; background: #ffffff; }
#iframe-overlay { position: absolute; inset: 0; display: none; place-items: center; background: rgba(36, 41, 46, 0.04); color: #586069; font-size: 14px; }
iframe#app-frame { width: 100%; height: 100%; border: 0; background: #fff; }