# Better UI > UI-polish principles for product interfaces. Use when building or reviewing surfaces, icons, micro-interactions, motion details, borders, shadows, optical alignment, or an interface that feels off. - Skill: `tommylower/better-ui` (Agent Skill, multi-file: 5 files) - Install (CLI): `npx skillmds@latest add tommylower/better-ui` - Raw SKILL.md: https://api.skillmd.com/api/skills/tommylower/better-ui/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: tommylower (https://skillmd.com/u/tommylower) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/tommylower/better-ui --- # Details that make interfaces feel better Great interfaces rarely come from a single thing. It's usually a collection of small details that compound into a great experience. Apply these principles when building or reviewing UI code. Adapted from Jakub Krehel's [`better-ui`](https://github.com/jakubkrehel/skills/tree/main/skills/better-ui) at commit `a67333399dabbc71d7778962cb9c4fb9b86a00d0`. When reviewing, slow the interface down: replay motion at 10% speed in the browser's Animations panel and walk every state: hover, focus, active, loading, empty. What feels off at 10% speed is what's subtly wrong at full speed. Preserve the project's component library, tokens, density, and motion language. Exact values in this skill are fallback recipes only when the project and Studio have no tuned value; they never override either source. Typography (text wrapping, font rendering, tabular numbers, spacing) is covered by the `better-typography` skill; use that for anything text-related. Accessibility (hit areas, focus states, keyboard support, ARIA, reduced motion) is covered by the `better-accessibility` skill. Layout structure (grouping, spacing between sections, breakpoints, spatial RTL) is covered by the `better-layout` skill. ## Quick Reference | Category | When to Use | | --- | --- | | [Surfaces](references/surfaces.md) | Border radius, optical alignment, adaptive chips, shadows, image outlines | | [Animations](references/animations.md) | Interruptible animations, enter/exit transitions, icon animations, scale on press, motion restraint | | [Icons](references/icons.md) | Icon stroke weight, states via `currentColor`, outline vs fill, sizing, RTL flipping | | [Performance](references/performance.md) | Transition specificity, `will-change` usage | ## Core Principles ### 1. Concentric Border Radius Outer radius = inner radius + padding. Mismatched radii on nested elements is the most common thing that makes interfaces feel off. ### 2. Optical Over Geometric Alignment When geometric centering looks off, align optically. Buttons with icons, play triangles, and asymmetric icons all need manual adjustment. ### 3. Shadows for Elevation, Borders for Structure For buttons, cards, and containers whose border exists only to create depth, prefer layered transparent `box-shadow` values. Keep borders that communicate structure or state: dividers, layout separators, and selected or focus states. ### 4. Interruptible Animations Use CSS transitions for interactive state changes: they can be interrupted mid-animation. Reserve keyframes for staged sequences that run once. ### 5. Split and Stagger Enter Animations For an infrequent staged entrance where sequence helps communicate hierarchy, break content into semantic chunks and stagger them by ~100ms instead of animating one container. Do not stagger routine, high-frequency interactions. ### 6. Subtle Exit Animations Use a small fixed `translateY` instead of full height. Exits should be softer than enters. Use the project's exit easing; absent one, tune against Studio's current motion default. ### 7. Contextual Icon Animations Animate icons with `opacity`, `scale`, and `blur` instead of toggling visibility. When no project recipe exists, start with scale `0.25` to `1`, opacity `0` to `1`, and blur `4px` to `0px`, then tune. If the project has `motion` or `framer-motion`, match its established import and transition language. Otherwise keep both icons in the DOM and cross-fade them with CSS transitions. ### 8. Image Outlines When images need a consistent edge, use the project's image-outline token. Without one, start with a subtle `1px` neutral-black outline in light mode and neutral-white in dark mode at low opacity. Avoid an accidental tinted neutral, which can read as dirt against the image edge. ### 9. Scale on Press A subtle press scale gives buttons tactile feedback. Without a project value, start at `0.96`; values below `0.95` usually feel exaggerated. Add a `static` escape when motion would distract. ### 10. Skip Animation on Page Load Use `initial={false}` on `AnimatePresence` to prevent enter animations on first render. Verify it doesn't break intentional entrance animations. ### 11. Never Use `transition: all` Always specify exact properties: `transition-property: scale, opacity`. Tailwind's `transition-transform` covers `transform, translate, scale, rotate`. ### 12. Use `will-change` Sparingly Only for `transform`, `opacity`, `filter`, the properties the GPU can composite. Never use `will-change: all`. Only add when you notice first-frame stutter. ### 13. Match Icon Stroke to Text Weight An icon next to text carries the text's optical weight. Match the project's icon system; without one, try `1.5px` beside regular text and `2px` beside semibold text. Keep one coherent icon family and stroke language per surface. ### 14. One SVG, Recolored per State Icons use `currentColor` and get their states (hover, selected, disabled) from CSS color and opacity, never from separate assets. Outline variant is the default; fill variant marks the active state. ### 15. Motion Restraint No custom animation on high-frequency interactions: the attention cost repeats on every trigger. Motion is never the only feedback channel; every animated state change also needs a static cue (color, icon, label). ### 16. Derive Adaptive Chips; Do Not Blend by Default For neutral chips and badges placed on changing surfaces, inherit the surface foreground with `currentColor` and derive translucent fills and borders from it. Keep semantic success, warning, error, and status colors on explicit tokens. Treat `mix-blend-mode` as an art-directed exception for controlled backdrops, not as the component-system default. ## Common Mistakes | Mistake | Fix | | --- | --- | | Same border radius on closely nested parent and child | Calculate `outerRadius = innerRadius + padding` | | Icons look off-center | Adjust optically with padding or fix SVG directly | | Border used only to fake elevation | Use layered `box-shadow` with transparency; keep structural and state borders | | Jarring staged entrance or contextual exit | Stagger infrequent entrances and keep context-preserving exits subtle | | Stateful icon or toggle animates its default state on page load | Add `initial={false}` to that `AnimatePresence`; preserve intentional page entrances | | `transition: all` on elements | Specify exact properties | | First-frame animation stutter | Add `will-change: transform` (sparingly) | | Hairline icon beside bold text | Match the stroke width to the text weight | | Separate icon assets per state | One `currentColor` SVG, states via CSS | | Filled icons everywhere | Outline as default, fill only for the active state | | Entrance animation on every hover or keystroke | Instant feedback or ≤150ms opacity/color transition | | `mix-blend-mode` used to make every chip adapt | Derive neutral chip fills from `currentColor`; keep semantic badges tokenized | ## Review Output Format Use this format only when the user asks for a standalone UI-polish review. When `studio-audit` orchestrates the review, provide domain evidence and findings to that skill and let its output format, severity scale, consolidation rules, cap, and verdict take precedence. Present the standalone review in two parts. ### Findings Group all confirmed findings by principle. Use a markdown table with **Severity**, **Location**, **Before**, **After**, and **Why** columns. Never use separate "Before:" / "After:" lines. - **Severity**: `HIGH` makes an interaction misleading, unresponsive, or repeatedly disruptive; `MEDIUM` creates a noticeable craft or consistency problem; `LOW` is isolated polish. - **Location**: cite `path/to/file:line`. If the artifact has no source files, cite the exact screen and component instead. - **Before / After**: show the current implementation and an actionable replacement. - **Why**: name the violated principle and explain how it affects the interface. Consolidate a repeated systemic issue into one row and list every affected location. Omit principles with no findings. ### Example #### Concentric border radius | Severity | Location | Before | After | Why | | --- | --- | --- | --- | --- | | LOW | `src/Card.tsx:28` | `rounded-xl` on card + `rounded-xl` on inner button (`p-2`) | `rounded-2xl` on card (`8 + 8 = 16`), `rounded-lg` on inner button | Nested corners should be concentric | | LOW | `src/card.css:11` | `border-radius: 16px` on both nested surfaces | Outer `24px`, inner `16px` with `8px` padding | Equal nested radii make the inner surface look pinched | #### Scale on press | Severity | Location | Before | After | Why | | --- | --- | --- | --- | --- | | LOW | `src/Button.tsx:19` | `