# Centre-fill filter chips

> Chips that fill with colour from the middle outwards, with a little bounce when you select one.

- Category: [Filters](https://library.aimran.es/components/filters)
- Built with: HTML + CSS
- Live editor: https://library.aimran.es/blocks/uv-f-chips-fill
- Library: AIMRAN Library (https://library.aimran.es), free, no sign-up, by Aimran Oukham

## Where to use it

Picture a recipe blog where readers switch between starters, mains, desserts and quick weeknight dinners. The colour blooming from the centre of the chip gives each tap a small, satisfying response, a bit like pressing a real button. It is a handy pick if you need category chips or a CSS filter button with some character.

The bounce is part of the charm, but on a page with lots of chips it can feel busy. Lower the speed a touch and pick one strong accent colour. With food photos around it, a warm tone usually sits better than a cold blue.

## Code

### HTML

```html
<div class="uv-fcf"><button class="on"><i></i><b>All</b></button><button><i></i><b>Design</b></button><button><i></i><b>Code</b></button><button><i></i><b>Photos</b></button><button><i></i><b>Video</b></button></div>
```

### CSS

```css
.uv-fcf {
  --c1: #0071e3;
  --c2: #8ec5ff;
  --s: 16px;
  /* tamaño */
  --k: 1;
  /* velocidad */
  --fg: #1d1d1f;
  /* texto */
  --bg: #f5f5f7;
  /* fondo */
}

.uv-fcf {
  font-family: -apple-system,BlinkMacSystemFont,"SF Pro Text","Inter",system-ui,sans-serif;
  font-size: var(--s);
  color: var(--fg);
  -webkit-tap-highlight-color: transparent;
  display: flex;
  flex-wrap: wrap;
  gap: .5em;
  justify-content: center;
}

.uv-fcf button {
  font-family: -apple-system,BlinkMacSystemFont,"SF Pro Text","Inter",system-ui,sans-serif;
  font-size: var(--s);
  font-weight: 550;
  line-height: 1;
  padding: .72em 1.25em;
  border: 0;
  border-radius: 999px;
  cursor: pointer;
  background: transparent;
  color: var(--fg);
  position: relative;
  transition: color calc(0.32s / var(--k)) cubic-bezier(.25,.1,.25,1),transform calc(0.32s / var(--k)) cubic-bezier(.34,1.56,.64,1);
  overflow: hidden;
  box-shadow: inset 0 0 0 1.5px color-mix(in srgb,var(--fg) 14%,transparent);
}

.uv-fcf b {
  position: relative;
  z-index: 1;
  font-weight: inherit;
}

.uv-fcf i {
  position: absolute;
  inset: 0;
  margin: auto;
  width: 130%;
  aspect-ratio: 1;
  border-radius: 50%;
  background: var(--c1);
  transform: scale(0);
  transition: transform calc(0.45s / var(--k)) cubic-bezier(.34,1.56,.64,1);
}

.uv-fcf button:hover {
  transform: translateY(-1px);
}

.uv-fcf button.on {
  color: #fff;
  box-shadow: inset 0 0 0 1.5px var(--c1),0 6px 16px color-mix(in srgb,var(--c1) 32%,transparent);
}

.uv-fcf button.on i {
  transform: scale(1);
}
```

### JavaScript

```js
document.querySelectorAll(".uv-fcf").forEach(el => {
  el.querySelectorAll("button").forEach(b=>b.addEventListener("click",()=>{el.querySelectorAll("button").forEach(x=>x.classList.remove("on"));b.classList.add("on")}))
});
```

### React

```tsx
// @ts-nocheck: setup() es JavaScript del DOM sin tipos, el mismo de la pestaña JS.
import { useEffect, useRef, type CSSProperties } from "react";

const css = `
.uv-fcf {
  font-family: -apple-system,BlinkMacSystemFont,"SF Pro Text","Inter",system-ui,sans-serif;
  font-size: var(--s);
  color: var(--fg);
  -webkit-tap-highlight-color: transparent;
  display: flex;
  flex-wrap: wrap;
  gap: .5em;
  justify-content: center;
}

.uv-fcf button {
  font-family: -apple-system,BlinkMacSystemFont,"SF Pro Text","Inter",system-ui,sans-serif;
  font-size: var(--s);
  font-weight: 550;
  line-height: 1;
  padding: .72em 1.25em;
  border: 0;
  border-radius: 999px;
  cursor: pointer;
  background: transparent;
  color: var(--fg);
  position: relative;
  transition: color calc(0.32s / var(--k)) cubic-bezier(.25,.1,.25,1),transform calc(0.32s / var(--k)) cubic-bezier(.34,1.56,.64,1);
  overflow: hidden;
  box-shadow: inset 0 0 0 1.5px color-mix(in srgb,var(--fg) 14%,transparent);
}

.uv-fcf b {
  position: relative;
  z-index: 1;
  font-weight: inherit;
}

.uv-fcf i {
  position: absolute;
  inset: 0;
  margin: auto;
  width: 130%;
  aspect-ratio: 1;
  border-radius: 50%;
  background: var(--c1);
  transform: scale(0);
  transition: transform calc(0.45s / var(--k)) cubic-bezier(.34,1.56,.64,1);
}

.uv-fcf button:hover {
  transform: translateY(-1px);
}

.uv-fcf button.on {
  color: #fff;
  box-shadow: inset 0 0 0 1.5px var(--c1),0 6px 16px color-mix(in srgb,var(--c1) 32%,transparent);
}

.uv-fcf button.on i {
  transform: scale(1);
}
`;

// Interacción en JavaScript del DOM: la misma que en la pestaña JS.
// eslint-disable-next-line @typescript-eslint/no-explicit-any
function setup(el: any) {
  el.querySelectorAll("button").forEach(b=>b.addEventListener("click",()=>{el.querySelectorAll("button").forEach(x=>x.classList.remove("on"));b.classList.add("on")}))
}

export default function FChipsFill() {
  const ref = useRef<HTMLDivElement>(null);

  useEffect(() => {
    const el = ref.current?.firstElementChild;
    return el ? setup(el) : undefined;
  }, []);

  return (
    <>
      <style>{css}</style>
      <div
        ref={ref} style={{
          "--c1": "#0071e3",
          "--c2": "#8ec5ff",
          "--s": "16px",
          "--k": "1",
          "--fg": "#1d1d1f",
          "--bg": "#f5f5f7",
        } as CSSProperties}
      >
        <div className="uv-fcf"><button className="on"><i></i><b>All</b></button><button><i></i><b>Design</b></button><button><i></i><b>Code</b></button><button><i></i><b>Photos</b></button><button><i></i><b>Video</b></button></div>
      </div>
    </>
  );
}
```

## Prompt for AI assistants

Paste this into ChatGPT, Claude, Cursor, v0 or Lovable to adapt the block to your stack (Tailwind, Vue, Svelte…):

````text
I want to add the “Centre-fill filter chips” block (Filters) from AIMRAN Library to my project.

## What it is
Chips that fill with colour from the middle outwards, with a little bounce when you select one.

## Chosen settings
- Main color: #0071e3
- Secondary color: #8ec5ff
- Size: 16px (from 12 to 24px)
- Speed: 1x (from 0.5 to 2x)

## What I need
1. Add it to my project with the same look and animation as the reference code: same sizes, colours, radii, shadows, timings and easing.
2. It is built with plain HTML and CSS (the reference wraps it in a React component with its CSS). If my project uses something else (Vue, Svelte, Astro, plain HTML…), translate it without losing any behaviour. If I use Tailwind, turn the styles into classes; if not, keep the CSS in its own file.
3. Expose the settings above as props (or CSS variables) with those values as defaults.
4. Make it work well on phones: nothing that depends only on hover, touch targets of at least 44 px and no overflow on 320 px screens.
5. Make it look right in light and dark mode.
6. Keep it accessible: semantic HTML, roles and aria-* where needed, visible focus and keyboard support.
7. Respect prefers-reduced-motion: with reduced motion, no big animations but the same end result.

## Reference code
```tsx
// @ts-nocheck: setup() es JavaScript del DOM sin tipos, el mismo de la pestaña JS.
import { useEffect, useRef, type CSSProperties } from "react";

const css = `
.uv-fcf {
  font-family: -apple-system,BlinkMacSystemFont,"SF Pro Text","Inter",system-ui,sans-serif;
  font-size: var(--s);
  color: var(--fg);
  -webkit-tap-highlight-color: transparent;
  display: flex;
  flex-wrap: wrap;
  gap: .5em;
  justify-content: center;
}

.uv-fcf button {
  font-family: -apple-system,BlinkMacSystemFont,"SF Pro Text","Inter",system-ui,sans-serif;
  font-size: var(--s);
  font-weight: 550;
  line-height: 1;
  padding: .72em 1.25em;
  border: 0;
  border-radius: 999px;
  cursor: pointer;
  background: transparent;
  color: var(--fg);
  position: relative;
  transition: color calc(0.32s / var(--k)) cubic-bezier(.25,.1,.25,1),transform calc(0.32s / var(--k)) cubic-bezier(.34,1.56,.64,1);
  overflow: hidden;
  box-shadow: inset 0 0 0 1.5px color-mix(in srgb,var(--fg) 14%,transparent);
}

.uv-fcf b {
  position: relative;
  z-index: 1;
  font-weight: inherit;
}

.uv-fcf i {
  position: absolute;
  inset: 0;
  margin: auto;
  width: 130%;
  aspect-ratio: 1;
  border-radius: 50%;
  background: var(--c1);
  transform: scale(0);
  transition: transform calc(0.45s / var(--k)) cubic-bezier(.34,1.56,.64,1);
}

.uv-fcf button:hover {
  transform: translateY(-1px);
}

.uv-fcf button.on {
  color: #fff;
  box-shadow: inset 0 0 0 1.5px var(--c1),0 6px 16px color-mix(in srgb,var(--c1) 32%,transparent);
}

.uv-fcf button.on i {
  transform: scale(1);
}
`;

// Interacción en JavaScript del DOM: la misma que en la pestaña JS.
// eslint-disable-next-line @typescript-eslint/no-explicit-any
function setup(el: any) {
  el.querySelectorAll("button").forEach(b=>b.addEventListener("click",()=>{el.querySelectorAll("button").forEach(x=>x.classList.remove("on"));b.classList.add("on")}))
}

export default function FChipsFill() {
  const ref = useRef<HTMLDivElement>(null);

  useEffect(() => {
    const el = ref.current?.firstElementChild;
    return el ? setup(el) : undefined;
  }, []);

  return (
    <>
      <style>{css}</style>
      <div
        ref={ref} style={{
          "--c1": "#0071e3",
          "--c2": "#8ec5ff",
          "--s": "16px",
          "--k": "1",
          "--fg": "#1d1d1f",
          "--bg": "#f5f5f7",
        } as CSSProperties}
      >
        <div className="uv-fcf"><button className="on"><i></i><b>All</b></button><button><i></i><b>Design</b></button><button><i></i><b>Code</b></button><button><i></i><b>Photos</b></button><button><i></i><b>Video</b></button></div>
      </div>
    </>
  );
}
```

Give me the complete final code, ready to paste, and tell me in one line where to put it in my project.
````