character sheet ofANTJANUS
pattern library · feats compendium

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

Preview

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

Source

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

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.

40 feats

Data display feat

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.

  • schedule
  • timeline
  • grid
  • flexbox

Added Aug 11, 2026

Data display feat

Benchmark progress bar


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

  • progress
  • benchmarks
  • css-only
  • data-viz

Added Aug 11, 2026

Data display feat

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.

  • table
  • matrix
  • sticky
  • accessibility

Added Aug 11, 2026

Data display feat

Left-truncating paths


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

  • truncation
  • paths
  • text-overflow
  • breadcrumbs

Added Aug 11, 2026

Data display feat Updated

Shape-mark sequence


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

  • stepper
  • sparkline
  • series
  • truncation

Updated Aug 21, 2026

Data display feat

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.

  • timeline
  • drill-down
  • css-only
  • data-viz

Added Aug 21, 2026

Data display feat

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.

  • meter
  • skeuomorphic
  • css-only
  • reduced-motion

Added Aug 21, 2026

Data display feat

Partitioned stage bar


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

  • progress
  • stacked-bar
  • batch
  • legend

Added Sep 12, 2026

Data display feat

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.

  • explainability
  • calculator
  • disclosure
  • formula

Added Sep 12, 2026

Data display feat Updated

Plan preview tree


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

  • dry-run
  • diff
  • tree
  • preview

Updated Sep 12, 2026

Data display feat

Uniform slot shell


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

  • dashboard
  • widgets
  • cards
  • empty-state

Added Sep 12, 2026

Layout feat Updated

Object-shaped cards


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

  • cards
  • css-only
  • gradients
  • variations

Updated Aug 11, 2026

Layout feat

Adaptive tile mosaic


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

  • css-grid
  • css-only
  • no-assets
  • cards

Added Aug 11, 2026

Layout feat Updated

Ground-scrimmed artwork


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

  • layout
  • css-only
  • gradients
  • contrast

Updated Aug 11, 2026

Layout feat Updated

Hairline stat strip


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

  • stats
  • css-grid
  • css-only
  • hairline

Updated Aug 21, 2026

Layout feat

Annotated transcript


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

  • conversation
  • gutter
  • status-roles
  • contrast

Added Aug 21, 2026

Layout feat

Cork notice board


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

  • skeuomorphic
  • gradients
  • no-assets
  • cards

Added Aug 21, 2026

Layout feat Updated

Hotspot marker layer


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

  • hotspots
  • pointer-events
  • aspect-ratio
  • container-query

Updated Sep 12, 2026

Layout feat

Line-art empty states


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

  • empty-state
  • svg
  • currentcolor
  • illustration

Added Sep 12, 2026

Layout feat

Column-flow wall


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

  • masonry
  • columns
  • break-inside
  • reading-order

Added Sep 12, 2026

Interaction feat

Scroll edge shadows


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

  • scrolling
  • affordance
  • lists
  • overflow

Added Aug 11, 2026

Interaction feat

Frozen-batch deck


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

  • queue
  • review-flow
  • animation
  • keyboard

Added Aug 11, 2026

Interaction feat Updated

Controls beside the anchor


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

  • cards
  • accessibility
  • keyboard
  • focus-within

Updated Aug 11, 2026

Interaction feat Updated

Pluggable canvas visualizer


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

  • canvas
  • visualization
  • registry
  • animation

Updated Aug 11, 2026

Interaction feat Updated

Roving-grid board


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

  • keyboard
  • roving-tabindex
  • accessibility
  • states

Updated Aug 21, 2026

Interaction feat

Section rail


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

  • navigation
  • toc
  • responsive
  • aria-current

Added Aug 21, 2026

Interaction feat

Ledge-press buttons


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

  • buttons
  • skeuomorphic
  • press
  • tokens

Added Aug 21, 2026

Interaction feat Updated

Guarded control


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

  • aria-disabled
  • disabled
  • preconditions
  • keyboard

Updated Sep 12, 2026

Interaction feat Updated

Polled job card


One card for every state a background job passes through.

  • progress
  • polling
  • background-job
  • indeterminate

Updated Sep 12, 2026

Interaction feat

Entry-transform motion


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

  • animation
  • transitions
  • reflow
  • reduced-motion

Added Sep 12, 2026

Interaction feat Updated

Slot-first picker


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

  • assignment
  • picker
  • aria-pressed
  • filtering

Updated Sep 12, 2026

Forms feat

Undo toast


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

  • undo
  • toast
  • destructive
  • aria-live

Added Aug 28, 2026

Forms feat New

Blast-radius confirm


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

  • confirm-dialog
  • destructive
  • cascade
  • dialog-element

Added Sep 28, 2026

Forms feat Updated

Batch action bar


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

  • selection
  • bulk-actions
  • toolbar
  • checkbox

Updated Aug 28, 2026

Forms feat

Filtered to zero


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

  • empty-state
  • filter
  • search
  • zero-results

Added Sep 12, 2026

Forms feat

Parsed query chips


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

  • search
  • query-syntax
  • chips
  • facets

Added Sep 12, 2026

Forms feat

Compound-value picker


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

  • select
  • optgroup
  • polymorphic
  • forms

Added Sep 12, 2026

Color feat Updated

Ground-referenced color


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

  • color
  • contrast
  • color-mix
  • accessibility

Updated Aug 11, 2026

Color feat Updated

Single-property color variants


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

  • color
  • color-mix
  • custom-properties
  • theming

Updated Aug 21, 2026

Color feat Updated

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.

  • contrast
  • brand-color
  • focus-ring
  • opacity

Updated Sep 12, 2026

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