# Sandbox.UI.PositionMode.Fixed

```csharp
static PositionMode Fixed
```

A root-viewport overlay that remains a logical child. Insets and percentages use the viewport,
ignoring ancestor scrolling, transforms and clipping. Unset insets start at the viewport's top-left
(not the CSS static position). Logical visibility and opacity still apply.

Declared in [Sandbox.UI.PositionMode](/api/Sandbox.UI.PositionMode).
Assembly: `Sandbox.System`.