esengine/packages/editor-app/src/styles/ResizablePanel.css

.resizable-panel {
  display: flex;
  width: 100%;
  height: 100%;
  position: relative;
}

.resizable-panel-horizontal {
  flex-direction: row;
}

.resizable-panel-vertical {
  flex-direction: column;
}

.panel-section {
  overflow: hidden;
  position: relative;
}

.resizer {
  background: var(--color-bg-elevated);
  position: relative;
  z-index: var(--z-index-base);
  transition: background-color var(--transition-fast);
  flex-shrink: 0;
}

.resizer:hover {
  background: var(--color-primary-subtle);
}

.resizer:active {
  background: var(--color-primary);
}

.resizer-horizontal {
  width: 4px;
  cursor: col-resize;
}

.resizer-vertical {
  height: 4px;
  cursor: row-resize;
}

.resizer-handle {
  position: absolute;
  background: transparent;
  pointer-events: none;
}

.resizer-horizontal .resizer-handle {
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 12px;
  height: 40px;
}

.resizer-vertical .resizer-handle {
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 40px;
  height: 12px;
}

body.resizing {
  cursor: col-resize !important;
  user-select: none !important;
}

body.resizing-vertical {
  cursor: row-resize !important;
  user-select: none !important;
}