# iOS-style segmented control

> A segmented control in the Apple style, where the white indicator stretches a little as it slides between options.

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

## Where to use it

The classic Day, Week, Month switch. It fits the stats screen of a fitness app, the chart on a sales dashboard or a calendar that changes its view. People already know this control from their phones, so nobody has to think about it. If you need an iOS segmented control in HTML and CSS, here it is.

Two to four options is the sweet spot. Beyond that the segments get narrow and the labels start to squeeze. It looks most at home on light grey panels; on a dark theme, tone down the indicator shadow.

## Code

### HTML

```html
<div class="uv-fsi"><span class="p"></span><button class="on">Day</button><button>Week</button><button>Month</button></div>
```

### CSS

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

.uv-fsi {
  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: .28em;
  border-radius: .85em;
  background: color-mix(in srgb,var(--fg) 8%,transparent);
}

.uv-fsi 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);
  border-radius: .6em;
  padding: .6em 1.4em;
  z-index: 1;
  font-weight: 600;
}

.uv-fsi button.on {
  color: var(--fg);
}

.uv-fsi .p {
  position: absolute;
  top: .28em;
  left: 0;
  height: calc(100% - .56em);
  border-radius: .6em;
  background: var(--bg);
  box-shadow: 0 3px 10px rgba(0,0,0,.14);
  transition: transform calc(0.4s / var(--k)) cubic-bezier(.25,.1,.25,1),width calc(0.4s / var(--k)) cubic-bezier(.25,.1,.25,1);
}

.uv-fsi .p.mv {
  animation: uv-fsi calc(0.4s / var(--k)) cubic-bezier(.25,.1,.25,1);
}

@keyframes uv-fsi {
  0% {
    scale: 1 1;
  }
  50% {
    scale: 1.14 .94;
  }
  100% {
    scale: 1 1;
  }
}
```

### JavaScript

```js
document.querySelectorAll(".uv-fsi").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)"};bs.forEach(b=>b.addEventListener("click",()=>{bs.forEach(x=>x.classList.remove("on"));b.classList.add("on");mv(b);p.classList.remove("mv");void p.offsetWidth;p.classList.add("mv")}));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-fsi {
  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: .28em;
  border-radius: .85em;
  background: color-mix(in srgb,var(--fg) 8%,transparent);
}

.uv-fsi 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);
  border-radius: .6em;
  padding: .6em 1.4em;
  z-index: 1;
  font-weight: 600;
}

.uv-fsi button.on {
  color: var(--fg);
}

.uv-fsi .p {
  position: absolute;
  top: .28em;
  left: 0;
  height: calc(100% - .56em);
  border-radius: .6em;
  background: var(--bg);
  box-shadow: 0 3px 10px rgba(0,0,0,.14);
  transition: transform calc(0.4s / var(--k)) cubic-bezier(.25,.1,.25,1),width calc(0.4s / var(--k)) cubic-bezier(.25,.1,.25,1);
}

.uv-fsi .p.mv {
  animation: uv-fsi calc(0.4s / var(--k)) cubic-bezier(.25,.1,.25,1);
}

@keyframes uv-fsi {
  0% {
    scale: 1 1;
  }
  50% {
    scale: 1.14 .94;
  }
  100% {
    scale: 1 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)"};bs.forEach(b=>b.addEventListener("click",()=>{bs.forEach(x=>x.classList.remove("on"));b.classList.add("on");mv(b);p.classList.remove("mv");void p.offsetWidth;p.classList.add("mv")}));requestAnimationFrame(()=>mv(el.querySelector("button.on")))
}

export default function FSegIos() {
  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-fsi"><span className="p"></span><button className="on">Day</button><button>Week</button><button>Month</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 “iOS-style segmented control” block (Filters) from AIMRAN Library to my project.

## What it is
A segmented control in the Apple style, where the white indicator stretches a little as it slides between options.

## 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-fsi {
  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: .28em;
  border-radius: .85em;
  background: color-mix(in srgb,var(--fg) 8%,transparent);
}

.uv-fsi 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);
  border-radius: .6em;
  padding: .6em 1.4em;
  z-index: 1;
  font-weight: 600;
}

.uv-fsi button.on {
  color: var(--fg);
}

.uv-fsi .p {
  position: absolute;
  top: .28em;
  left: 0;
  height: calc(100% - .56em);
  border-radius: .6em;
  background: var(--bg);
  box-shadow: 0 3px 10px rgba(0,0,0,.14);
  transition: transform calc(0.4s / var(--k)) cubic-bezier(.25,.1,.25,1),width calc(0.4s / var(--k)) cubic-bezier(.25,.1,.25,1);
}

.uv-fsi .p.mv {
  animation: uv-fsi calc(0.4s / var(--k)) cubic-bezier(.25,.1,.25,1);
}

@keyframes uv-fsi {
  0% {
    scale: 1 1;
  }
  50% {
    scale: 1.14 .94;
  }
  100% {
    scale: 1 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)"};bs.forEach(b=>b.addEventListener("click",()=>{bs.forEach(x=>x.classList.remove("on"));b.classList.add("on");mv(b);p.classList.remove("mv");void p.offsetWidth;p.classList.add("mv")}));requestAnimationFrame(()=>mv(el.querySelector("button.on")))
}

export default function FSegIos() {
  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-fsi"><span className="p"></span><button className="on">Day</button><button>Week</button><button>Month</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.
````