Scroll Fade

Utilities for adding a fade effect to the edges of a scroll container.

The scroll-fade utility is purely composed of CSS and is based on shadcn/scroll-fade. No extensions to rxconfig.py are needed as it uses Tailwind v4 syntax.

Installation

If your project was set up with buridan init, you already have scroll-fade. It ships with the buridan package, which the CLI imports in your global CSS file.

Otherwise install the buirdan package:

uv run buridan init

Usage

Class Styles
scroll-fade mask-image: var(--scroll-fade-mask, var(--scroll-fade-block));
animation-timeline: scroll(self y);
scroll-fade-y mask-image: var(--scroll-fade-mask, var(--scroll-fade-block));
animation-timeline: scroll(self y);
scroll-fade-x mask-image: var(--scroll-fade-mask, var(--scroll-fade-inline));
animation-timeline: scroll(self inline);
scroll-fade-t Fade mask on the top edge.
animation-timeline: scroll(self y);
scroll-fade-b Fade mask on the bottom edge.
animation-timeline: scroll(self y);
scroll-fade-l Fade mask on the left edge.
animation-timeline: scroll(self x);
scroll-fade-r Fade mask on the right edge.
animation-timeline: scroll(self x);
scroll-fade-s Fade mask on the start edge, mirrors in RTL.
animation-timeline: scroll(self inline);
scroll-fade-e Fade mask on the end edge, mirrors in RTL.
animation-timeline: scroll(self inline);
scroll-fade-<number> --scroll-fade-size: calc(var(--spacing) * <number>);
scroll-fade-[<value>] --scroll-fade-size: <value>;
scroll-fade-{t,b,s,e}-<number> --scroll-fade-{t,b,s,e}-size: calc(var(--spacing) * <number>);
scroll-fade-{t,b,s,e}-[<value>] --scroll-fade-{t,b,s,e}-size: <value>;
scroll-fade-none --scroll-fade-mask: none;

Add scroll-fade or scroll-fade-y to the scroll container, i.e. the element that has overflow-y-auto.

The fade is scroll-aware and tracks the scroll position:

  • At rest, the top edge is crisp and the bottom edge fades to hint at more content.
  • As you scroll, a fade appears at the top and both edges stay faded mid-scroll.
  • At the end, the bottom edge sharpens to show you have reached the last item.

The fade is applied with mask-image, so it dissolves the content itself rather than overlaying a color. The mask uses a linear fade from transparent to black, so it adapts to any background without configuration. If your scroll area sits inside a card, put the background and border on a wrapper and scroll-fade on the inner scroller, so the fade dissolves the content and not the card.

Scroll Fade Demo

Item 1
Item 2
Item 3
Item 4
Item 5
Item 6
Item 7
Item 8
Item 9
Item 10
Item 11
Item 12

No Overflow, No Fade

If the content does not overflow, no fade is shown. You can apply scroll-fade to any list without checking whether it scrolls.

Item 1
Item 2
Item 3

Horizontal Scrolling

Use scroll-fade-x on containers that scroll horizontally, i.e. the element that has overflow-x-auto.

Design
Engineering
Marketing
Product
Research
Sales
Support
Operations
Finance
Legal
People
Security

Edge Fades

Use edge utilities when only one edge should track the scroll position.

Inbox triage
Design review
API contract
QA pass
Launch notes
Metrics follow-up

scroll-fade-t

Inbox triage
Design review
API contract
QA pass
Launch notes
Metrics follow-up

scroll-fade-b

Design
Engineering
Marketing
Product
Research
Sales
Support
Operations

scroll-fade-s

Design
Engineering
Marketing
Product
Research
Sales
Support
Operations

scroll-fade-e

The edge utilities are scroll-aware. Start edges fade in after you scroll away from the start, and end edges fade out when you reach the end. Use scroll-fade-t, scroll-fade-b, scroll-fade-l, and scroll-fade-r for physical edges. Use scroll-fade-s and scroll-fade-e for logical inline edges.

Fade Size

The fade depth defaults to 12% of the container, capped at 40px so tall scrollers stay subtle. Use scroll-fade-<number> to set a fixed size on the spacing scale instead, the same way scroll-mt-<number> works.

Item 1
Item 2
Item 3
Item 4
Item 5
Item 6
Item 7
Item 8

scroll-fade-4

Item 1
Item 2
Item 3
Item 4
Item 5
Item 6
Item 7
Item 8

scroll-fade-24

For one-off values, use an arbitrary length or percentage:

rx.el.div(..., class_name="scroll-fade overflow-y-auto scroll-fade-[15%]")

To fade opposite edges by different amounts, use the per-edge modifiers scroll-fade-t-<number>, scroll-fade-b-<number>, scroll-fade-s-<number>, and scroll-fade-e-<number>. They override scroll-fade- on the edge they target and accept arbitrary values too.

rx.el.div(..., class_name="scroll-fade overflow-y-auto scroll-fade-b-8 scroll-fade-t-2")

Disabling the Fade

Use scroll-fade-none to remove the fade. It works in any class order, so the typical use is responsive or stateful.

Item 1
Item 2
Item 3
Item 4
Item 5
Item 6
Item 7
Item 8

scroll-fade

Item 1
Item 2
Item 3
Item 4
Item 5
Item 6
Item 7
Item 8

scroll-fade scroll-fade-none

Fallback

The scroll-aware behavior is implemented with CSS scroll-driven animations, with no JavaScript and no scroll listeners. In browsers that do not support scroll-driven animations, scroll-fade falls back to a static fade on both edges, and edge utilities fall back to a static fade on the selected edge.

Since the mask is applied to the scroll container itself, a visible scrollbar fades with the content at the edges. Pair scroll-fade with no-scrollbar, which ships in the same package, if you want to hide the scrollbar entirely.