sigil/UI

ProximityGlow

Pointer-proximity glow border using CSS mask-composite and conic-gradient angle tracking.

Import

import { ProximityGlow, ProximityGlowCard } from "@sigil-ui/components";

Preview

Usage

<ProximityGlow proximity={100} spread={60} blur={4}>
  <ProximityGlowCard>Content here</ProximityGlowCard>
  <ProximityGlowCard>Content here</ProximityGlowCard>
</ProximityGlow>

How it works

Three layers combine to create the effect:

1. Masked conic-gradient border

The ::before pseudo-element on each card uses mask-composite: intersect with two mask layers — one clips to the padding box, the other to the border box. Their intersection reveals only the border region:

[data-glow]::before {
  mask-clip: padding-box, border-box;
  mask-composite: intersect;
  mask:
    linear-gradient(transparent, transparent),
    conic-gradient(from calc(var(--glow-angle) * 1deg), ...);
}

2. Pointer angle tracking

On pointermove, JavaScript calculates the angle between the pointer and each card's center using Math.atan2, then sets --glow-angle as a scoped custom property:

let angle = Math.atan2(
  event.y - cardCenter[1],
  event.x - cardCenter[0]
) * 180 / Math.PI;

card.style.setProperty('--glow-angle', angle + 90);

3. Blurred glow layer

The ::after pseudo-element duplicates the masked gradient with filter: blur() for the soft glow halo. Both layers fade in only when the pointer is within the configured proximity distance.

Props

ProximityGlow

PropTypeDefaultDescription
proximitynumber100Max distance (px) before the glow appears.
spreadnumber60Spread angle (deg) of the conic-gradient mask.
blurnumber4Blur radius (px) for the glow layer.

ProximityGlowCard

No custom props — accepts all standard div attributes.

Token integration

CSS VariablePurpose
--s-primaryGlow color
--s-card-radiusCard and glow border radius
--s-surfaceCard background
--s-borderCard border color
--s-border-styleCard border style
--s-card-paddingCard padding
--s-duration-fastGlow fade transition speed
Studiodefault
Presets
primary
secondary
background
surface
text
border
accent
success
warning
error
info
display
body
mono
heading wt
600
heading trk
-0.025em
base size
16px
page margin
24px
section pad
64px
card pad
24px
grid gap
24px
stack gap
12px
global
8px
button
8px
card
12px
input
6px
border w
1px
style
card border
card shadow
btn shadow
glow
spring
Type
Duration
0.20
Bounce
1.00
easing
cubic-bezier(0.16, 1, 0.3, 1)
fast
150ms
normal
200ms
slow
300ms
hover scale
1.02
press scale
0.98
hover lift
-1px
stagger
50ms
weight
transform
hover
active scale
0.98
min-width
0px
letter sp
0.000em
icon gap
8px
shadow
hover
border
shadow
padding
24px
title size
1px
title wt
desc size
0.875px
aspect
outline
height
36px
focus ring
2px
focus ring
h1 size
2.25px
h2 size
1.875px
h3 size
1.5px
h4 size
1.25px
weight
tracking
-0.020em
leading
1.20
pattern
pattern α
0.03
noise
gradient
grad angle
180°
height
50px
blur
12px
border
padding
24px
item gap
24px
min-height
600px
padding Y
80px
content-max
680px
layout
title size
56px
desc size
18px
padding Y
64px
max-width
600px
layout
title size
36px
padding Y
48px
columns
4
gap
36px
content-max
1200px
rail-gap
24px
grid-cell
50px
cross-stroke
1.5px
navbar-h
50px
bento-gap
16px
grid lines
dots
cell borders
cell bg
Gutter
Margin
content
hero
navbar
rail visible
enabled