Skip to content

No.144 · Cursors

Loupe

A jeweller's glass for dense content. The pointer becomes a round lens that magnifies whatever is under it — a live second copy of the page, not a screenshot, so fine type and map lines stay sharp at any power. Alt + scroll or [ ] change the power; on touch, press and hold.

The prompt

The design brief behind this component — reuse it to regenerate, remix, or explain it.

Build a magnifying-glass cursor as a wrapper component that renders its children twice. Structure: the host (position relative, overflow hidden) renders children normally, then an aria-hidden lens: a circular div (prop size, default 200px) with overflow hidden, containing a second copy of the children inside a view div marked inert. The view is sized to the host's offsetWidth/Height (kept in sync with a ResizeObserver) and transformed with transform-origin 0 0 to translate(S/2 − x·z, S/2 − y·z) scale(z), so the host-local point (x, y) under the pointer sits at the centre of the lens at power z. Give the view no will-change, so the browser re-rasterises it at the scaled size and text and SVG stay crisp. The lens itself is translated to (x − S/2, y − S/2) in the pointermove handler — it is the pointer — and the system cursor is hidden inside the host while it is up (fine pointers only). Coordinates are host-local, corrected by rect.width / offsetWidth. Glass: a soft drop shadow beneath; inset hairline rim, a 5px inner band, a bright bevel along the top, a darker one along the bottom, a faint vignette and a sheen gradient from the upper left; a 14px reticle at the centre; the power engraved as a small mono pill on the lower rim, brightening for 1.2s when it changes. Motion: power and appearance are springs (k 240 ζ 0.9 for power, k 420 ζ 0.72 for the lens scale). Entering the host grows the lens from 0.55 with a slight overshoot; leaving shrinks it away. Alt + wheel multiplies the power by 1.12 per notch; [ and ] (or − and +) step by 0.25; the range is clamped (default 1.5–4) and rounded to quarters. Touch: a 380ms press-and-hold (cancelled by more than 8px of movement, so scrolling still works) raises the lens 0.62 × size above the finger; touchmove is then prevented, so dragging moves the lens instead of the page; lifting the finger puts it away. Ids inside the content must be unique per copy (useId). Demo: an engraved map sheet of Muttrah (contours, depth lines, cased corniche with a textPath label, tiny POI notes) beside fine-print walking notes and a bus timetable. Paper and Night.

Notes

Interaction
Hover the sheet to read the fine print through the lens. Alt + scroll, or [ and ], change the power. On touch, press and hold, then drag.
Motion
Lens grows in from 0.55 on a spring (k 420, ζ 0.72); power on a spring (k 240, ζ 0.9); readout 200ms.
Accessibility
The magnified copy is inert and aria-hidden, so assistive tech reads the page only once; the map has a text alternative and the notes are real text and a captioned table. Browser zoom keeps working. Reduced motion shows and hides the lens and changes power with no springs.
Responsive
The sheet stacks under 1024px; the lens copy tracks the host's size, so it lines up at every width and inside scaled previews.
On touch
Press and hold for 380ms, then drag: the lens rises above your finger so it isn't hidden by it. A quick swipe still scrolls.

Featured

01Glassbreak ButtonA solid plate that fractures from one impact point, cracks racing outward as the shards drift apart.04Liquid GlassA capsule of glass that bends what's behind it, carries a specular highlight around its rim toward your pointer, and squashes like a drop of liquid when pressed.07Phosphor Glass ButtonA liquid-glass pill that senses you coming: its rim light turns to face the cursor and the pill leans in to meet it.08Iris ShutterAn async button with a camera iris for a status light — blades close and turn while it works, then open onto the result.
81Atmosphere CardSmoked-glass link cards: colour pooled in the corners, slow contour currents underneath, a field that leans toward you.93Eclipse Event CardAn editorial event plate with an oversized date and an orbital eclipse bleeding in from the right, alive with slow drift.94Specimen CardAn object mounted under glass: hover lifts the pane with a sweep of reflection and swings out a paper catalogue tag.
95Silk FieldDomain-warped light that pours like liquid silk, with an optional glass lens that refracts the flow under your cursor.106IsobarA living weather map — contour lines traced over a drifting pressure field, with your cursor as a system of its own.
151Prompt ComposerA chat composer where attached files tuck into its top edge like tabs in a folder — they rise from behind it when added and sink back when removed. Send turns into stop while the reply streams.157Aura FieldA writing field where colour only exists while the AI is touching your text: the edge becomes a turning band of light and the words are rewritten in place, one by one, out of a soft blur.
205Halftone CTAA tall CTA banner where slow gold paint drifts beneath a fixed halftone grid, visible only through the dots.
212Nocturne Sign-inA single quiet column on near-black with a breathing seam of frost light behind it — email, password, magic link, nothing more.222Sigil Sign-inA split sign-in whose left half grows a geometric mark from your email — the same address always draws the same sigil.
275Voices CarouselA testimonial exhibition: one large quote at a time on frosted glass, crossfading between voices without ever resizing.
279Feral TitleA brutal condensed wordmark — heartbeat in the dark, letters slam in, a gash tears through and the word bleeds.
301 components