> ## Documentation Index
> Fetch the complete documentation index at: https://docs.asquareportal.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Containers & Auto-layout

> The single feature that turns a frozen drawing into a living, editable design.

# Containers & Auto-layout

Containers are the beating heart of Portals — the single feature that turns a frozen drawing into a living, editable design. Everything the AI generates is built on them, and once you feel how they behave, you'll never draw a static layout again.

## The idea

A container is a box that **lays out its children for you**. Drop shapes and text inside it, and instead of each element sitting wherever you dragged it, they arrange themselves according to rules: *flow in a row or column, wrap or not, align to an edge or the center, keep a gap between items, respect padding on the inside*.

The magic is what happens next: **resize the container and its children reflow.** Pull it wider and a row of buttons spreads out; make it narrower and wrapped items drop to the next line; add text and the whole stack breathes to fit. The design doesn't break — it adapts. That's why generated designs survive being edited: they were *built*, not drawn.

## Anatomy of a container

A container is made of the same parts, and we'll meet each one in the Properties panel when you select it:

* **Flow (Direction)** — `Row` lays children side by side along the main axis; `Column` stacks them top to bottom. This one decision shapes the whole layout.
* **Wrap** — `No wrap` keeps everything on one line (they'll squash rather than break); `Wrap` lets items flow onto the next line when they run out of room.
* **Align** — where children sit on the cross axis: start, center, or end. The little alignment grid in the panel is the fastest way to feel it — click a corner and watch the children jump.
* **Distribute** — how children spread along the main axis: `Between` pushes the first and last to the edges with equal gaps between, `Around` gives each item equal space on both sides, `Evenly` spaces everything identically.
* **Gap** — the breathing room between children, in pixels.
* **Padding** — the breathing room *inside* the container, between its edge and the first row of children.

## Hands-on: the first container

1. Grab the **Container** tool from the top-center toolbar (the two-column icon — the same icon the layers panel uses for containers, so the object has one identity everywhere).
2. Click and drag a box out on the canvas. That's your container — it already has Flow, Gap, and Padding set to sensible defaults.
3. Draw a couple of rectangles and some text, then drag them **inside** the container. Watch the layers panel: they nest underneath it.
4. Select the container and open the Properties panel. Flick the Direction between Row and Column and watch the children re-flow instantly. Crank the Gap and feel the spacing change live.
5. Now resize the container by dragging a corner. The children ride along — that's auto-layout keeping your design honest.

## Containers vs. frames

A **frame** (the artboard) is a freeform canvas — a page, a poster, a slide. It has a fixed size and elements sit on it wherever you put them. A **container** is what lives *inside* frames: the structured regions that hold and arrange content. The frame is where the design happens; containers are how the design stays coherent when it changes.

## Why this matters for AI

The vector design agent doesn't output a picture — it outputs **containers with children inside them**, exactly the objects you can keep editing. When a generated design lets you drag a button, retype a headline, or change a color and everything else reflows to fit, that's the container pipeline doing its job: nested containers, real text, real spacing — nothing flattened.