/* ── Main area and tab panels ── */
.main { flex: 1; min-height: 0; overflow: hidden; display: flex; flex-direction: column; }
.tab-panel { display: none; flex: 1; overflow: hidden; min-height: 0; }
.tab-panel.active { display: flex; }

/* ── Shared resize handle ── */
.rtp-resize-handle {
  width: 5px;
  cursor: col-resize;
  background: var(--border);
  transition: background .15s;
  position: relative;
  z-index: 10;
}
.rtp-resize-handle:hover,
.rtp-resize-handle.dragging { background: var(--accent); }

/* ── Generate tab layout ── */
.gen-layout {
  flex: 1;
  min-height: 0;
  display: grid;
  grid-template-columns: var(--gen-col-width, 500px) 5px 1fr;
  overflow: hidden;
}

/* ── Form column (shared by Generate and RTP) ── */
.form-col {
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: var(--surface2);
  min-height: 0;
}
.form-col-header {
  flex-shrink: 0;
  height: 44px;
  padding: 0 1.25rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--surface);
}
.form-col-title {
  font-size: 0.67rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--text3);
}
.form-scroll {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  padding: 1rem 1.25rem 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.form-scroll::-webkit-scrollbar { width: 6px; }
.form-scroll::-webkit-scrollbar-track { background: transparent; }
.form-scroll::-webkit-scrollbar-thumb { background: var(--border-hi); border-radius: 3px; }

/* ── Output column (Generate tab right side) ── */
.output-col { display: flex; flex-direction: column; overflow: hidden; }
.output-col-header {
  flex-shrink: 0;
  height: 44px;
  padding: 0 1rem;
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--surface);
}
.output-col-title {
  font-size: 0.67rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: .1em;
  color: var(--text3);
}
.output-col-actions { display: flex; align-items: center; gap: 0.5rem; }
.output-body { flex: 1; overflow: hidden; display: flex; flex-direction: column; min-height: 0; }