# Colour-shifting segmented control

> A segmented control whose background and indicator shift tone depending on the option you choose.

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

## Where to use it

Made for status filters. A to-do app switching between All, Active and Done, or the orders page of an online shop showing pending, shipped and delivered. The colour change gives each state its own mood, so people notice at a glance which view they are in. Worth a look if you need a status filter or colour-coded tabs.

Choose colours that make sense for the states: a neutral tone for “All”, something greener for finished work. Don't rely on colour alone, though. The label still has to say what is selected, for people who can't tell the shades apart.

## Code

### HTML

```html
<div class="uv-fsc" style="--t:0"><span class="p"></span><button data-t="0" class="on">All</button><button data-t="1">Active</button><button data-t="2">Done</button></div>
```

### CSS

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

.uv-fsc {
  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;
  position: relative;
  display: inline-flex;
  padding: .3em;
  border-radius: 999px;
  background: color-mix(in srgb,var(--c1) calc(8% + var(--t) * 6%),transparent);
  transition: background calc(0.45s / var(--k)) cubic-bezier(.25,.1,.25,1);
}

.uv-fsc 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);
  z-index: 1;
}

.uv-fsc button.on {
  color: #fff;
}

.uv-fsc .p {
  position: absolute;
  top: .3em;
  left: 0;
  height: calc(100% - .6em);
  border-radius: 999px;
  background: color-mix(in srgb,var(--c1) calc(100% - var(--t) * 34%),var(--c2));
  box-shadow: 0 8px 20px color-mix(in srgb,var(--c1) 34%,transparent);
  transition: transform calc(0.42s / var(--k)) cubic-bezier(.34,1.56,.64,1),width calc(0.42s / var(--k)) cubic-bezier(.34,1.56,.64,1),background calc(0.45s / var(--k)) cubic-bezier(.25,.1,.25,1);
}
```

### JavaScript

```js
document.querySelectorAll(".uv-fsc").forEach(el => {
  const p=el.querySelector(".p"),bs=[...el.querySelectorAll("button")];const mv=b=>{p.style.width=b.offsetWidth+"px";p.style.transform="translateX("+b.offsetLeft+"px)";el.style.setProperty("--t",b.dataset.t)};bs.forEach(b=>b.addEventListener("click",()=>{bs.forEach(x=>x.classList.remove("on"));b.classList.add("on");mv(b)}));requestAnimationFrame(()=>mv(el.querySelector("button.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-fsc {
  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;
  position: relative;
  display: inline-flex;
  padding: .3em;
  border-radius: 999px;
  background: color-mix(in srgb,var(--c1) calc(8% + var(--t) * 6%),transparent);
  transition: background calc(0.45s / var(--k)) cubic-bezier(.25,.1,.25,1);
}

.uv-fsc 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);
  z-index: 1;
}

.uv-fsc button.on {
  color: #fff;
}

.uv-fsc .p {
  position: absolute;
  top: .3em;
  left: 0;
  height: calc(100% - .6em);
  border-radius: 999px;
  background: color-mix(in srgb,var(--c1) calc(100% - var(--t) * 34%),var(--c2));
  box-shadow: 0 8px 20px color-mix(in srgb,var(--c1) 34%,transparent);
  transition: transform calc(0.42s / var(--k)) cubic-bezier(.34,1.56,.64,1),width calc(0.42s / var(--k)) cubic-bezier(.34,1.56,.64,1),background calc(0.45s / var(--k)) cubic-bezier(.25,.1,.25,1);
}
`;

// 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) {
  const p=el.querySelector(".p"),bs=[...el.querySelectorAll("button")];const mv=b=>{p.style.width=b.offsetWidth+"px";p.style.transform="translateX("+b.offsetLeft+"px)";el.style.setProperty("--t",b.dataset.t)};bs.forEach(b=>b.addEventListener("click",()=>{bs.forEach(x=>x.classList.remove("on"));b.classList.add("on");mv(b)}));requestAnimationFrame(()=>mv(el.querySelector("button.on")))
}

export default function FSegColor() {
  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-fsc" style={{ "--t": "0" } as CSSProperties}><span className="p"></span><button data-t="0" className="on">All</button><button data-t="1">Active</button><button data-t="2">Done</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 “Colour-shifting segmented control” block (Filters) from AIMRAN Library to my project.

## What it is
A segmented control whose background and indicator shift tone depending on the option you choose.

## 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-fsc {
  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;
  position: relative;
  display: inline-flex;
  padding: .3em;
  border-radius: 999px;
  background: color-mix(in srgb,var(--c1) calc(8% + var(--t) * 6%),transparent);
  transition: background calc(0.45s / var(--k)) cubic-bezier(.25,.1,.25,1);
}

.uv-fsc 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);
  z-index: 1;
}

.uv-fsc button.on {
  color: #fff;
}

.uv-fsc .p {
  position: absolute;
  top: .3em;
  left: 0;
  height: calc(100% - .6em);
  border-radius: 999px;
  background: color-mix(in srgb,var(--c1) calc(100% - var(--t) * 34%),var(--c2));
  box-shadow: 0 8px 20px color-mix(in srgb,var(--c1) 34%,transparent);
  transition: transform calc(0.42s / var(--k)) cubic-bezier(.34,1.56,.64,1),width calc(0.42s / var(--k)) cubic-bezier(.34,1.56,.64,1),background calc(0.45s / var(--k)) cubic-bezier(.25,.1,.25,1);
}
`;

// 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) {
  const p=el.querySelector(".p"),bs=[...el.querySelectorAll("button")];const mv=b=>{p.style.width=b.offsetWidth+"px";p.style.transform="translateX("+b.offsetLeft+"px)";el.style.setProperty("--t",b.dataset.t)};bs.forEach(b=>b.addEventListener("click",()=>{bs.forEach(x=>x.classList.remove("on"));b.classList.add("on");mv(b)}));requestAnimationFrame(()=>mv(el.querySelector("button.on")))
}

export default function FSegColor() {
  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-fsc" style={{ "--t": "0" } as CSSProperties}><span className="p"></span><button data-t="0" className="on">All</button><button data-t="1">Active</button><button data-t="2">Done</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.
````