[ @sdxc/u/overflow ]

scroll-margin

Applies logical scroll-margin on a scroll item, growing the box the container aligns when it snaps to this item or an anchor jump targets it, so a sticky header clears only the items that need the extra room.

MDN: logical properties

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import { scrollMargin } from "@sdxc/u/overflow";

Quick reference

Every documented call, beside the CSS it emits.

Call	CSS
`u.scrollMargin(4)`	`css({ scrollMargin: "calc(var(--ui-spacing, 0.25rem) * 4)" })`
`u.scrollMargin(16, 0)`	`css({ scrollMarginBlock: "...", scrollMarginInline: "..." })`

Examples

Basic example

Use scrollMargin(n) on the targets of an anchor jump to land them clear of a sticky header. Click a link and the section stops below the header:

Sticky header

Section 1

Section 2

Section 3

<div mix={[vstack({ gap: 4 }), is(72), maxIs("100%")]}>
	<nav mix={[hstack({ gap: 3 })]}>
		<a href="#margined-1">Section 1</a>
		<a href="#margined-2">Section 2</a>
		<a href="#margined-3">Section 3</a>
	</nav>
	<div mix={[scroll("y"), vstack({ gap: 3 }), bs(56), pi(4), pbe(4), ...]}>
		<header mix={[sticky(), insBs(0), bg(), p(3), ...]}>Sticky header</header>
		<section id="margined-1" mix={[scrollMargin(14), shrink(), bs(32), ...]}>
			Section 1
		</section>
		<section id="margined-2" mix={[scrollMargin(14), shrink(), bs(32), ...]}>
			Section 2
		</section>
		<section id="margined-3" mix={[scrollMargin(14), shrink(), bs(32), ...]}>
			Section 3
		</section>
	</div>
</div>

Insetting snapped items

Pass a block and an inline value, like scrollMargin(0, 8), to grow the area each item snaps by. Scroll the row and each card settles away from the edge:

<div
	mix={[
		scroll("x"),
		scrollSnapType(),
		hstack({ gap: 4 }),
		is(96),
		maxIs("100%"),
		p(4),
		...,
	]}
>
	<div mix={[scrollSnapAlign(), scrollMargin(0, 8), shrink(), is(56), bs(32), ...]}>
		1
	</div>
	<div mix={[scrollSnapAlign(), scrollMargin(0, 8), shrink(), is(56), bs(32), ...]}>
		2
	</div>
	<div mix={[scrollSnapAlign(), scrollMargin(0, 8), shrink(), is(56), bs(32), ...]}>
		3
	</div>
	<div mix={[scrollSnapAlign(), scrollMargin(0, 8), shrink(), is(56), bs(32), ...]}>
		4
	</div>
</div>

Using a custom value

Every scale argument also takes a raw CSS value, which passes through untouched.

u.scrollMargin("2.75rem")

Applying on a state

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

u.hover(u.scrollMargin(4))

Responsive design

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

u.at("md", u.scrollMargin(4))

Customizing your theme

Customizing spacing

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

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

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

scrollMargin(4)

Signature

u.scrollMargin(...values: SpacingValue[])