ANTJANUS1-bit edition
Pattern library

UI Patterns

A UI pattern library built for coding agents. 40 patterns, each shipping a copy-paste prompt that rebuilds it inside your own codebase — plus a live preview and the source behind it.

A blueprint drawing of interface parts: dialled gauges, dimensioned panels, and a grid of repeated tiles

Every pattern, three ways

01

Preview

The pattern running live in an isolated frame, in whichever theme you are reading in.

02

Source

Its markup, styles and behaviour, plus a single runnable file carrying its own palette.

03

Prompt

A written spec that rebuilds the pattern from scratch — including why each decision is the way it is. Paste it into Claude Code, Cursor, or any coding agent.

The prompts are the point. Each one is written to survive being handed to an agent with no other context: it names the surfaces the pattern belongs on, spells out the constraint that makes it work, and calls out the failure it exists to prevent. Nothing here is a dependency you install.

All patterns

40 patterns

Data display · #01

Windowed schedule grid

Rows of resources against a fixed time window, where each block is sized by its overlap with the window rather than by its own duration.

Added 2026-08-11
scheduletimelinegridflexbox
Data display · #02

Benchmark progress bar

Places a raw figure on a scale of external benchmarks instead of printing it plain.

Added 2026-08-11
progressbenchmarkscss-onlydata-viz
Data display · #03

Cross-highlight matrix

A two-axis lookup table with both headers sticky, hover lighting the full row and column at once, and a durable click-to-pin selection for touch.

Added 2026-08-11
tablematrixstickyaccessibility
Data display · #04

Left-truncating paths

Shortens a long path by dropping whole segments from the left, because the tail is what tells two paths apart.

Added 2026-08-11
truncationpathstext-overflowbreadcrumbs
Data display · #05Updated

Shape-mark sequence

A sequence compressed into a row of small marks whose shape carries the state.

Updated 2026-08-21
steppersparklineseriestruncation
Data display · #06

Linked month bars

A month-by-month volume timeline built from plain divs where every aggregate row links to the filtered view that produced it.

Added 2026-08-21
timelinedrill-downcss-onlydata-viz
Data display · #07

Glass vial meter

A vertical potion-vial meter whose liquid fills a wide bulb first and then rises into a narrow neck — all CSS, no images.

Added 2026-08-21
meterskeuomorphiccss-onlyreduced-motion
Data display · #08

Partitioned stage bar

Progress for work with several possible endings, drawn as a census rather than a fraction.

Added 2026-09-12
progressstacked-barbatchlegend
Data display · #09

Term-by-term derivation

A computed figure shown with the audit trail behind it — the number is the product and the derivation is the receipt.

Added 2026-09-12
explainabilitycalculatordisclosureformula
Data display · #10Updated

Plan preview tree

A dry run shown as a before-and-after tree with counts now, after, and the difference.

Updated 2026-09-12
dry-rundifftreepreview
Data display · #11

Uniform slot shell

One card shell many independent sources render through, where the shell does the capping.

Added 2026-09-12
dashboardwidgetscardsempty-state
Layout · #12Updated

Object-shaped cards

Where a record stands for a physical thing, the card is drawn as that thing — nine variations in pure gradients.

Updated 2026-08-11
cardscss-onlygradientsvariations
Layout · #13

Adaptive tile mosaic

A container with no artwork draws one from up to four member tiles, grid tracks following tile count.

Added 2026-08-11
css-gridcss-onlyno-assetscards
Layout · #14Updated

Ground-scrimmed artwork

Text printed over unreviewed artwork, scrimmed to an alpha that can be written down rather than guessed.

Updated 2026-08-11
layoutcss-onlygradientscontrast
Layout · #15Updated

Hairline stat strip

Stat tiles joined by hairlines that are grid gap, not borders.

Updated 2026-08-21
statscss-gridcss-onlyhairline
Layout · #16

Annotated transcript

Conversation bubbles with a speaker-colored spine and a fixed metadata gutter.

Added 2026-08-21
conversationgutterstatus-rolescontrast
Layout · #17

Cork notice board

Pinned paper notes on a cork board where every texture is layered CSS gradients.

Added 2026-08-21
skeuomorphicgradientsno-assetscards
Layout · #18Updated

Hotspot marker layer

Markers at percentage coordinates over a fixed-aspect picture, turning into a list when too narrow.

Updated 2026-09-12
hotspotspointer-eventsaspect-ratiocontainer-query
Layout · #19

Line-art empty states

Inline drawings for empty surfaces stroked in the inherited text colour.

Added 2026-09-12
empty-statesvgcurrentcolorillustration
Layout · #20

Column-flow wall

Cards flowing down columns instead of across rows, with the reading-order cost stated plainly.

Added 2026-09-12
masonrycolumnsbreak-insidereading-order
Interaction · #21

Scroll edge shadows

An inset shadow shown only on the edge that has more content behind it.

Added 2026-08-11
scrollingaffordancelistsoverflow
Interaction · #22

Frozen-batch deck

A one-card-at-a-time review queue whose batch is snapshotted at mount.

Added 2026-08-11
queuereview-flowanimationkeyboard
Interaction · #23Updated

Controls beside the anchor

Per-card controls over a fully-linked card without nesting interactive elements in the anchor.

Updated 2026-08-11
cardsaccessibilitykeyboardfocus-within
Interaction · #24Updated

Pluggable canvas visualizer

One canvas, a registry of draw modes, each mode owning its entire frame.

Updated 2026-08-11
canvasvisualizationregistryanimation
Interaction · #25Updated

Roving-grid board

A dense grid of state cells that is one tab stop with arrow-key navigation.

Updated 2026-08-21
keyboardroving-tabindexaccessibilitystates
Interaction · #26

Section rail

Sticky vertical rail on wide screens, wrapping tab row on narrow ones, from the same markup.

Added 2026-08-21
navigationtocresponsivearia-current
Interaction · #27

Ledge-press buttons

Buttons on a solid ledge shadow that travel down onto it when pressed.

Added 2026-08-21
buttonsskeuomorphicpresstokens
Interaction · #28Updated

Guarded control

A blocked control stays focusable, carries the reason as text, and refuses in its handler.

Updated 2026-09-12
aria-disableddisabledpreconditionskeyboard
Interaction · #29Updated

Polled job card

One card for every state a background job passes through.

Updated 2026-09-12
progresspollingbackground-jobindeterminate
Interaction · #30

Entry-transform motion

FLIP-style motion between two rendered states when the old DOM is already gone.

Added 2026-09-12
animationtransitionsreflowreduced-motion
Interaction · #31Updated

Slot-first picker

Assignment that starts at the destination slot, then narrows the catalogue.

Updated 2026-09-12
assignmentpickeraria-pressedfiltering
Forms · #32

Undo toast

A destructive action with no confirm dialog, held behind a toast and committed when it expires.

Added 2026-08-28
undotoastdestructivearia-live
Forms · #33New

Blast-radius confirm

A confirm dialog that names everything a delete cascades and blocks dismissal while it runs.

Added 2026-09-28
confirm-dialogdestructivecascadedialog-element
Forms · #34Updated

Batch action bar

A bar that exists only while something is selected, states the count in words, caps at five actions.

Updated 2026-08-28
selectionbulk-actionstoolbarcheckbox
Forms · #35

Filtered to zero

The three empty states a list actually has, written as three different screens.

Added 2026-09-12
empty-statefiltersearchzero-results
Forms · #36

Parsed query chips

A search box that echoes back how it read the text as removable chips.

Added 2026-09-12
searchquery-syntaxchipsfacets
Forms · #37

Compound-value picker

One grouped select whose value carries both the kind and the id.

Added 2026-09-12
selectoptgrouppolymorphicforms
Color · #38Updated

Ground-referenced color

Colors solved against the page's own ground token so they invert correctly between themes.

Updated 2026-08-11
colorcontrastcolor-mixaccessibility
Color · #39Updated

Single-property color variants

One custom property carries the hue; border, fill, spine and dot derive from it.

Updated 2026-08-21
colorcolor-mixcustom-propertiestheming
Color · #40Updated

Controls on an unknown fill

Opaque controls, a gradient-darkened fill, and a two-tone focus ring on a surface whose colour arrives from outside.

Updated 2026-09-12
contrastbrand-colorfocus-ringopacity