/* App shell layout */

.topnav {
  height: var(--topnav-height);
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-4);
  background: var(--ui-bg);
  border-bottom: 1px solid var(--ui-border);
}

.topnav__brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.topnav__logo { height: 20px; width: auto; }

.topnav__product {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--color-accent);
  padding-left: var(--space-2);
  margin-left: var(--space-1);
  border-left: 1px solid var(--ui-border);
  line-height: 1;
}

.topnav__subtitle {
  font-size: var(--text-xs);
  color: var(--ui-text-muted);
  margin-left: var(--space-2);
  padding-left: var(--space-2);
  border-left: 1px solid var(--ui-border);
}

.topnav__actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.topnav__menu {
  position: relative;
}
.topnav__menu-dropdown {
  position: absolute;
  top: calc(100% + 4px);
  right: 0;
  min-width: 180px;
  background: var(--ui-bg);
  border: 1px solid var(--ui-border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  padding: 4px;
  z-index: 20;
  display: flex;
  flex-direction: column;
}
.topnav__menu-item {
  display: flex;
  align-items: center;
  gap: 8px;
  width: 100%;
  padding: 8px 10px;
  font-size: var(--text-sm);
  color: var(--ui-text);
  background: none;
  border: none;
  border-radius: var(--radius-sm);
  text-align: left;
  cursor: pointer;
}
.topnav__menu-item:hover {
  background: var(--ui-bg-subtle);
}

.workspace {
  flex: 1 1 auto;
  display: flex;
  min-height: 0;
}

.editor-panel {
  flex: 0 0 auto;
  display: flex;
  flex-direction: column;
  background: var(--ui-bg);
  border-right: 1px solid var(--ui-border);
  min-height: 0;
  /* Without this, a wide child (the data grid table, especially after a
     transpose adds many columns) forces this flex item wider than its own
     basis — the classic flexbox "children ignore my width" trap — and the
     panel gets visibly, sometimes irreversibly, stuck too wide. */
  min-width: 0;
  overflow-x: hidden;
}

.editor-panel__tabs {
  flex: 0 0 auto;
  display: flex;
  border-bottom: 1px solid var(--ui-border);
  padding: var(--space-2);
  gap: var(--space-1);
  background: var(--ui-bg-subtle);
}

.editor-panel__tab {
  flex: 1 1 0;
  padding: 9px var(--space-3);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--ui-text-secondary);
  background: transparent;
  border: none;
  text-align: center;
  transition: background 0.12s ease, color 0.12s ease;
}
.editor-panel__tab:hover { color: var(--ui-text); }
.editor-panel__tab--active {
  background: var(--ui-bg);
  color: var(--ui-text);
  box-shadow: var(--shadow-sm);
}

.editor-panel__empty-hint {
  margin-top: var(--space-4);
  text-align: center;
  color: var(--ui-text-muted);
}

.editor-panel__body {
  flex: 1 1 auto;
  overflow-y: auto;
  overflow-x: hidden;
  min-width: 0;
  padding: var(--space-3);
}

.editor-panel__resize-handle {
  flex: 0 0 6px;
  cursor: col-resize;
  background: transparent;
  position: relative;
}
.editor-panel__resize-handle::after {
  content: '';
  position: absolute;
  top: 0; bottom: 0;
  left: 2px;
  width: 2px;
  background: var(--ui-border);
}
.editor-panel__resize-handle:hover::after,
.editor-panel__resize-handle--active::after {
  background: var(--color-primary);
}

.preview-pane {
  flex: 1 1 auto;
  display: flex;
  flex-direction: column;
  min-width: 0;
  background: var(--ui-bg-canvas);
}

.preview-pane__toolbar {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-2) var(--space-4);
  border-bottom: 1px solid var(--ui-border);
  background: var(--ui-bg);
}

.preview-pane__canvas-wrap {
  flex: 1 1 auto;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: auto;
  padding: var(--space-6);
}

.statusbar {
  height: var(--statusbar-height);
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-4);
  background: var(--ui-bg);
  border-top: 1px solid var(--ui-border);
  font-size: var(--text-xs);
  color: var(--ui-text-muted);
}

@media (max-width: 1279px) {
  .editor-panel { flex-basis: 300px; }
}