# Elastic iOS toggle

> An iPhone-style switch whose knob stretches while you hold it down, then springs into place.

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

## Where to use it

This iOS toggle switch is the one people expect in a settings screen: “Push notifications”, “Dark mode” or “Share usage data” in the preferences of a web app. It copies a detail from the iPhone that many CSS switches skip: while you keep it pressed, the knob stretches like a drop, and on release it springs to the other side.

The stretch only shows while holding, so it is felt more than noticed, and that's the point. Green gives you the native iPhone look; your brand color makes it feel like part of your own product.

## Code

### HTML

```html
<label class="uv-ti"><input type="checkbox" checked><span></span></label>
```

### CSS

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

.uv-ti {
  display: inline-block;
  font-size: var(--s);
  cursor: pointer;
}

.uv-ti input {
  display: none;
}

.uv-ti span {
  position: relative;
  display: block;
  width: 3.2em;
  height: 1.9em;
  border-radius: 999px;
  background: color-mix(in srgb,var(--fg) 18%,transparent);
  transition: background calc(0.3s / var(--k)) cubic-bezier(.25,.1,.25,1);
}

.uv-ti span::after {
  content: "";
  position: absolute;
  left: .15em;
  top: .15em;
  width: 1.6em;
  height: 1.6em;
  border-radius: 999px;
  background: #fff;
  box-shadow: 0 2px 6px rgba(0,0,0,.25);
  transition: all calc(0.35s / var(--k)) cubic-bezier(.34,1.56,.64,1);
}

.uv-ti:active span::after {
  width: 2.1em;
}

.uv-ti input:checked+span {
  background: var(--c1);
}

.uv-ti input:checked+span::after {
  left: calc(100% - 1.75em);
}

.uv-ti:active input:checked+span::after {
  left: calc(100% - 2.25em);
}
```

### React

```tsx
import type { CSSProperties } from "react";

const css = `
.uv-ti {
  display: inline-block;
  font-size: var(--s);
  cursor: pointer;
}

.uv-ti input {
  display: none;
}

.uv-ti span {
  position: relative;
  display: block;
  width: 3.2em;
  height: 1.9em;
  border-radius: 999px;
  background: color-mix(in srgb,var(--fg) 18%,transparent);
  transition: background calc(0.3s / var(--k)) cubic-bezier(.25,.1,.25,1);
}

.uv-ti span::after {
  content: "";
  position: absolute;
  left: .15em;
  top: .15em;
  width: 1.6em;
  height: 1.6em;
  border-radius: 999px;
  background: #fff;
  box-shadow: 0 2px 6px rgba(0,0,0,.25);
  transition: all calc(0.35s / var(--k)) cubic-bezier(.34,1.56,.64,1);
}

.uv-ti:active span::after {
  width: 2.1em;
}

.uv-ti input:checked+span {
  background: var(--c1);
}

.uv-ti input:checked+span::after {
  left: calc(100% - 1.75em);
}

.uv-ti:active input:checked+span::after {
  left: calc(100% - 2.25em);
}
`;

export default function TgIos() {
  return (
    <>
      <style>{css}</style>
      <div
        style={{
          "--c1": "#0071e3",
          "--c2": "#8ec5ff",
          "--s": "16px",
          "--k": "1",
          "--fg": "#1d1d1f",
          "--bg": "#f5f5f7",
        } as CSSProperties}
      >
        <label className="uv-ti"><input type="checkbox" checked={true} /><span></span></label>
      </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 “Elastic iOS toggle” block (Toggles) from AIMRAN Library to my project.

## What it is
An iPhone-style switch whose knob stretches while you hold it down, then springs into place.

## 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
import type { CSSProperties } from "react";

const css = `
.uv-ti {
  display: inline-block;
  font-size: var(--s);
  cursor: pointer;
}

.uv-ti input {
  display: none;
}

.uv-ti span {
  position: relative;
  display: block;
  width: 3.2em;
  height: 1.9em;
  border-radius: 999px;
  background: color-mix(in srgb,var(--fg) 18%,transparent);
  transition: background calc(0.3s / var(--k)) cubic-bezier(.25,.1,.25,1);
}

.uv-ti span::after {
  content: "";
  position: absolute;
  left: .15em;
  top: .15em;
  width: 1.6em;
  height: 1.6em;
  border-radius: 999px;
  background: #fff;
  box-shadow: 0 2px 6px rgba(0,0,0,.25);
  transition: all calc(0.35s / var(--k)) cubic-bezier(.34,1.56,.64,1);
}

.uv-ti:active span::after {
  width: 2.1em;
}

.uv-ti input:checked+span {
  background: var(--c1);
}

.uv-ti input:checked+span::after {
  left: calc(100% - 1.75em);
}

.uv-ti:active input:checked+span::after {
  left: calc(100% - 2.25em);
}
`;

export default function TgIos() {
  return (
    <>
      <style>{css}</style>
      <div
        style={{
          "--c1": "#0071e3",
          "--c2": "#8ec5ff",
          "--s": "16px",
          "--k": "1",
          "--fg": "#1d1d1f",
          "--bg": "#f5f5f7",
        } as CSSProperties}
      >
        <label className="uv-ti"><input type="checkbox" checked={true} /><span></span></label>
      </div>
    </>
  );
}
```

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