Make Interfaces Feel Better

# Make Interfaces Feel Better

Use this skill for the small design-engineering details that compound into a
more polished interface.

Source: salvaged from stale community PR #1659 by `linus707`.

## When to Use

- The user says the UI feels off, flat, generic, cramped, jumpy, or unfinished.
- You are building controls, cards, lists, dashboards, navigation, forms, or
  toolbars.
- A component needs hover, active, focus, enter, exit, loading, or empty states.
- A frontend review needs specific before/after recommendations.

## Core Principles

### Concentric Radius

For nearby nested rounded surfaces:

```text
outer radius = inner radius + padding
```

If padding is large, treat layers as separate surfaces instead of forcing the
math. The point is optical coherence, not formula worship.

### Optical Alignment

Geometric centering is not always visual centering. Icon buttons, play
triangles, arrows, stars, and asymmetric icons often need a small offset. Fix the
SVG when possible; otherwise adjust with a pixel-level margin or padding change.

### Shadows And Borders

Use borders for separation and focus rings. Use layered shadows when a card,
button, dropdown, or popover needs depth. Shadows should be transparent and
subtle enough to work across backgrounds.

### Text Wrapping

- Use `text-wrap: balance` on headings and short titles.
- Use `text-wrap: pretty` on short-to-medium body text, captions, descriptions,
  and list items.
- Avoid both on long prose, code, and preformatted content.
- Use `font-variant-numeric: tabular-nums` for counters, timers, prices, tables,
  and other updating numbers.

### Font Smoothing

On macOS, apply antialiased font smoothing at the root layout when the project
does not already do so:

```css
html {
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}
```

### Image Outlines

Images often need a subtle inset outline so their edges do not blur into the
surface.

```css
img {
  outline: 1px solid rgba(0, 0, 0, 0.1);
  outline-offset: -1px;
}

@media (prefers-color-scheme: dark) {
  img {
    outline-color: rgba(255, 255, 255, 0.1);
  }
}
```

Use neutral black or white alpha outlines. Do not tint image outlines with the
brand palette.

### Motion

Use CSS transitions for interactive state changes because they can retarget
when the user changes intent mid-motion. Reserve keyframes for staged
one-shot entrances or loading sequences.

Good motion defaults:

- Enter: combine opacity, small `translateY`, and optionally blur.
- Exit: shorter and quieter than enter, usually 150ms.
- Press: `scale(0.96)` for tactile buttons, with a way to disable it when the
  movement distracts.
- Icon swaps: cross-fade with opacity, scale, and blur instead of instant
  visibility toggles.

### Transition Scope

Never use `transition: all`. Specify the changed properties:

```css
.button {
  transition-property: transform, background-color, box-shadow;
  transition-duration: 150ms;
  transition-timing-function: ease-out;
}
```

Use `will-change` only for first-frame stutter on compositor-friendly
properties such as `transform`, `opacity`, and `filter`. Never use
`will-change: all`.

### Hit Areas

Interactive controls should have at least a 40x40px hit area, ideally 44x44px
where the layout allows it. Expand with a pseudo-element when the visible icon
is smaller, but do not let expanded hit areas overlap.

## Review Output

When reviewing a UI polish pass, report concrete changes in before/after rows:

| Principle | Before | After |
| --- | --- | --- |
| Concentric radius | Same radius on parent and child | Parent radius accounts for padding |
| Tabular numbers | Counter shifts as digits change | Counter uses