/* ── Header ────────────────────────────────────────────────── */
.app-header {
  background: var(--card); border-bottom: 1px solid var(--border);
  padding: 10px 20px; display: flex; align-items: center; gap: 12px; flex-shrink: 0;
}
.app-header h1 {
  font-size: 17px; font-weight: 600; letter-spacing: 4px;
  background: linear-gradient(90deg, var(--cs), var(--accent), var(--math));
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
}
#statsLabel { margin-left: auto; font-size: 11px; color: var(--muted); }

/* ── Three-column layout ───────────────────────────────────── */
.layout { display: flex; flex: 1; overflow: hidden; }

.left-panel {
  width: 260px; flex-shrink: 0; background: var(--card); border-right: 1px solid var(--border);
  overflow-y: auto; padding: 16px; display: flex; flex-direction: column; gap: 18px;
}
.center-panel { flex: 1; position: relative; overflow: hidden; }
#scatter { display: block; width: 100%; height: 100%; }

.right-panel {
  width: 360px; flex-shrink: 0; background: var(--card); border-left: 1px solid var(--border);
  display: flex; flex-direction: column; overflow: hidden;
}

/* ── Tabs ──────────────────────────────────────────────────── */
.tabs { display: flex; border-bottom: 1px solid var(--border); flex-shrink: 0; }
.tab {
  flex: 1; padding: 10px 6px; text-align: center; font-size: 10px; letter-spacing: 1px;
  cursor: pointer; color: var(--muted); border: none; border-bottom: 2px solid transparent;
  background: none; font-family: inherit; transition: all .2s; border-radius: 0; width: auto;
}
.tab:hover { color: var(--text); }
.tab.on { color: var(--accent); border-bottom-color: var(--accent); }
.tab-content { display: none; flex: 1; overflow-y: auto; padding: 16px; flex-direction: column; gap: 16px; }
.tab-content.on { display: flex; }