# inline-size

> Applies `inline-size` — the logical width, which is the physical height in a vertical writing mode.

```ts
import { is } from "@sdxc/u/size";
```

Applies `inline-size` — the logical width, which is the physical height
in a vertical writing mode.

## Quick reference

Every documented call, beside the CSS it emits.

| Call | CSS |
| --- | --- |
| `u.is("full")` | `css({ inlineSize: "100%" })` |

## Examples

### Basic example

Use `is(n)` with a step of the spacing scale, like `is(32)` or `is(64)`, to set an element's inline size, its width in horizontal text:

```tsx
<div mix={[...]}>
	<div mix={[is(96), ...]}>is(96)</div>
	<div mix={[is(80), ...]}>is(80)</div>
	<div mix={[is(64), ...]}>is(64)</div>
	<div mix={[is(48), ...]}>is(48)</div>
	<div mix={[is(40), ...]}>is(40)</div>
	<div mix={[is(32), ...]}>is(32)</div>
</div>
```

### Percentages

Use `is("full")` to fill the container's inline size, or pass any CSS length as a string, like `is("50%")`:

```tsx
<div mix={[...]}>
	<div mix={[is("full"), ...]}>is("full")</div>
	<div mix={[is("75%"), ...]}>is("75%")</div>
	<div mix={[is("50%"), ...]}>is("50%")</div>
	<div mix={[is("25%"), ...]}>is("25%")</div>
</div>
```

### Vertical writing modes

`is()` sizes the inline axis, so in a vertical writing mode like `vertical-rl` it sets the element's height instead of its width:

```tsx
<div mix={[...]}>
	<div mix={[is(40), bs(16), ...]}>horizontal-tb</div>
	<div mix={[is(40), bs(16), raw({ writingMode: "vertical-rl" }), ...]}>
		vertical-rl
	</div>
</div>
```

## Applying on a state

Wrap the call in a state utility to scope it to one selector.

```ts
u.hover(u.is("full"))
```

## Responsive design

Wrap the call in a container query to scope it to one width.

```ts
u.at("md", u.is("full"))
```

## Customizing your theme

### Customizing spacing

Every numeric step multiplies `--ui-spacing`, so redefining it rescales every spacing and sizing utility at once:

```css
:root {
	--ui-spacing: 0.25rem;
}
```

Every call that names the step now reads the new value:

```ts
is(4)
```

## Signature

```ts
u.is(value: SizeValue)
```