# Add to Cart

> Add-to-cart button that confirms with a tick while a copy of the product picture flies into the cart icon and its count rolls up by one. Rolls back if the request fails.

Buttons · button, cart, ecommerce, counter, woocommerce · HTML, CSS, vanilla JS · no dependencies · updated 2026-10-26
Demo: https://kodza.dev/components/add-to-cart/

## Files

The code below, served as files: byte for byte what the Kodza site copies (the CSS includes its theme guard).

- [`kodza-add-to-cart.css`](https://kodza.dev/registry/add-to-cart/kodza-add-to-cart.css) · 10.5 KB
- [`kodza-add-to-cart.js`](https://kodza.dev/registry/add-to-cart/kodza-add-to-cart.js) · 16.9 KB
- [`kodza-add-to-cart.html`](https://kodza.dev/registry/add-to-cart/kodza-add-to-cart.html) · 0.8 KB · the markup, to adapt and paste into your page

**Can you run shell commands? Download the CSS and the JS, don't retype them.** Retyping costs thousands of tokens and can drop or change lines of the CSS. Put the files where your stack expects them (Use it says where: change the `-o` paths):

```bash
curl -fsSL --create-dirs -o kodza/kodza-add-to-cart.css https://kodza.dev/registry/add-to-cart/kodza-add-to-cart.css
curl -fsSL --create-dirs -o kodza/kodza-add-to-cart.js https://kodza.dev/registry/add-to-cart/kodza-add-to-cart.js
```

Then load the files from your page as Use it shows, instead of pasting the content. The HTML is the part you adapt (text, links, modifiers): paste it from the Code section. Copy the CSS and the JS from the Code section only if you can't run commands, exactly as they are. (Windows PowerShell: `curl.exe`.)

## API

- Root: `.kodza-add-to-cart, .kodza-add-to-cart__cart`
- Variables (set them on the root element itself: it declares its own defaults):
  - `--kz-add-to-cart-bg: #0a0a0a`
  - `--kz-add-to-cart-fg: #ffffff`
  - `--kz-add-to-cart-height: 52px`
  - `--kz-add-to-cart-pad-x: 28px`
  - `--kz-add-to-cart-ease: cubic-bezier(0.22, 1, 0.36, 1)`
  - `--kz-add-to-cart-ink: #0a0a0a`
  - `--kz-add-to-cart-paper: #ffffff`
  - `--kz-add-to-cart-cart-size: 44px`
  - `--kz-add-to-cart-cart-hover: rgba(10, 10, 10, 0.06)`
- Modifiers: `.kodza-add-to-cart--soft`
- Attributes:
  - `data-cart`
  - `data-count` (e.g. `0`)
  - `data-image`
  - `data-quantity`
- Events: `kodza:add` (bubbling, from the root)
- Lifecycle: `kodza:init` / `kodza:destroy` on `document`, with `{ detail: { root } }` to target a container.

## Keyboard

What each key does, by where the focus is. Keep it working when you adapt the HTML: same elements, same classes.

- On the button (focus in `.kodza-add-to-cart`):
  - `Enter` / `Space`: Adds the product, the picture flies to the cart

## Dark mode

The values Kodza uses on a dark background (`#0a0a0a`). For a page that follows the system theme, add them after the component's CSS:

```css
@media (prefers-color-scheme: dark) {
  .kodza-add-to-cart {
    --kz-add-to-cart-bg: #ffffff;
    --kz-add-to-cart-fg: #0a0a0a;
  }

  .kodza-add-to-cart__cart {
    --kz-add-to-cart-ink: #ffffff;
    --kz-add-to-cart-paper: #0a0a0a;
    --kz-add-to-cart-cart-hover: rgba(255, 255, 255, 0.1);
  }
}
```

A site with its own theme switch puts the same rules under its dark selector instead (`[data-theme="dark"] .kodza-add-to-cart { … }`); a single dark section, under that section's class.

## Use it

### Plain HTML page

- CSS: `kodza/kodza-add-to-cart.css` next to the page (the Files commands as they are), linked in `<head>`: `<link rel="stylesheet" href="kodza/kodza-add-to-cart.css">`. Without a shell, paste it in a `<style>` in `<head>` instead. It only touches `kodza-` classes.
- HTML: where the component goes. Paste it as many times as you need: instances never interfere.
- JS: `kodza/kodza-add-to-cart.js`, loaded with `<script src="kodza/kodza-add-to-cart.js" defer></script>` in `<head>`. Without a shell, paste it in a `<script>` before `</body>` (or in `<head>`: it waits for the page). One copy per page, whatever the number of instances.
- Restyle with the `--kz-…` variables, set on the component's root element itself (the root declares its own defaults, so a value on an ancestor is ignored), and with the modifiers / attributes listed under API.
- Font: it takes the page's own. The Kodza look is Geist: `<link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Geist:wght@400;500;600;700&family=Geist+Mono:wght@400;500&display=swap">`.
- Content added later (AJAX navigation, a SPA route, a builder preview): start it with `document.dispatchEvent(new CustomEvent('kodza:init', { detail: { root: container } }))`; before removing it, the same call with `'kodza:destroy'` stops it and puts the original markup back.

### Claude artifact (claude.ai)

- Paste the CSS in a `<style>` and the JS in a `<script>` at the end, in the artifact itself: it loads stylesheets only from Google Fonts and scripts only from a few CDNs, so no `<link>` or `<script src>` to Kodza.
- Writing the artifact file with a shell? Insert the downloaded files (Files) with a command instead of retyping them: a line `KODZA-CSS` alone inside the `<style>`, `KODZA-JS` inside the `<script>`, then `sed -e '/^KODZA-CSS$/{r kodza/kodza-add-to-cart.css' -e 'd' -e '}' -e '/^KODZA-JS$/{r kodza/kodza-add-to-cart.js' -e 'd' -e '}' page.html > artifact.html`.
- Font: load Geist from Google Fonts (allowed): `<link rel="stylesheet" href="https://fonts.googleapis.com/css2?family=Geist:wght@400;500;600;700&family=Geist+Mono:wght@400;500&display=swap">`.
- Dark mode: the viewer sets `data-theme="dark"` or `"light"` on `<html>`, or nothing when it follows the system. Write the Dark mode rules twice: inside `@media (prefers-color-scheme: dark)` with `:root:not([data-theme="light"])` in front of each selector, and with `:root[data-theme="dark"]` in front of each selector.

### WordPress

- HTML: a **Custom HTML** block (or a pattern / template part). WordPress keeps this markup as it is only for users allowed to post unfiltered HTML (Administrators; Super Admins on multisite): for anyone else it strips tags such as `<svg>`, `<input>` or `<dialog>`, so add it from the theme (a pattern or template part) instead.
- This one is inline (it flows like a word): pasted alone, many themes leave it at the edge of the page (block themes, and classic ones like Twenty Twenty-One or Blocksy), so put the Custom HTML block inside a **Group** block to line it up with the text.
- CSS and JS: the downloaded files go in the theme, under `wp-content/themes/<your-theme>/kodza/` (the child theme if there is one), enqueued from its functions.php (or a code-snippets plugin):
  ```php
  add_action('wp_enqueue_scripts', function () {
    $dir = get_stylesheet_directory() . '/kodza/';
    $uri = get_stylesheet_directory_uri() . '/kodza/';
    wp_enqueue_style('kodza-add-to-cart', $uri . 'kodza-add-to-cart.css', [], filemtime($dir . 'kodza-add-to-cart.css'));
    wp_enqueue_script('kodza-add-to-cart', $uri . 'kodza-add-to-cart.js', [], filemtime($dir . 'kodza-add-to-cart.js'), true);
  });
  ```
  Scoped to `kodza-` classes, the CSS never touches the theme. One copy of the JS, whatever the number of blocks.
- No access to the theme files? The CSS can also go, as it is, in **Appearance → Customize → Additional CSS** (classic theme) or **Styles → Additional CSS** in the Site Editor (block theme).
- Theme with AJAX page transitions: fire `kodza:init` on the new content after each swap (and `kodza:destroy` on the old one).
- Performance plugin (WP Rocket, LiteSpeed Cache, Perfmatters…) with **Delay JavaScript execution** turned on: add `kodza` to the scripts it must not delay. Otherwise the component waits for the visitor's first scroll, tap or mouse move, and that first click can be lost.
- Colours: it takes the colour of the text around it (or keeps its own monochrome): nothing to point at the theme.
- WordPress turns straight quotes and `--` into typographic ones in the text of a Custom HTML block (not inside `<code>` or `<pre>`).

#### With Elementor

- HTML: an **HTML** widget (Elementor shows it to administrators only). It keeps the code exactly as pasted, straight quotes included.
- CSS and JS: as above. Elementor's Site Settings → Theme Style styles every button, field, link and image of the page, components included; the theme guard at the end of the CSS keeps the component's buttons, fields and link colours as they are.
- The Elementor editor redraws each widget after the page has loaded: without the script below, the component stays still in the editor preview (the published page works). Add it once per site, in the footer like the component's script (`kodza/elementor-editor.js`, or a code-snippets plugin):

```js
// Kodza in the Elementor editor: the editor redraws each HTML widget after the page has loaded.
// Start Kodza in what it draws, stop it in what it replaces or removes. Once per site.
window.addEventListener('elementor/frontend/init', () => {
  if (!elementorFrontend.isEditMode()) return;
  class KodzaWidget extends elementorModules.frontend.handlers.Base {
    onInit() {
      super.onInit();
      this.kodza = [...this.$element[0].children];
      document.dispatchEvent(new CustomEvent('kodza:init', { detail: { root: this.$element[0] } }));
    }
    onDestroy() {
      super.onDestroy();
      this.kodza.forEach((root) => document.dispatchEvent(new CustomEvent('kodza:destroy', { detail: { root } })));
    }
  }
  elementorFrontend.elementsHandler.attachHandler('html', KodzaWidget);
});
```

- No child theme: everything can go in the HTML widget instead, `<style>` with the CSS, the HTML, then `<script>` with the JS. It works on the page and in the editor without the script above. This one reads the page around it, and a script in the widget runs before the rest of the page exists: put its `<script>` in an HTML widget at the bottom of the page instead.

### Shopify

- Files: `assets/kodza-add-to-cart.css` and `assets/kodza-add-to-cart.js` (the Files commands with `-o assets/…`).
- In the section: `{{ 'kodza-add-to-cart.css' | asset_url | stylesheet_tag }}` and `<script src="{{ 'kodza-add-to-cart.js' | asset_url }}" defer></script>`, then the HTML.
- The theme editor re-renders sections: restart them with
  `document.addEventListener('shopify:section:load', (e) => document.dispatchEvent(new CustomEvent('kodza:init', { detail: { root: e.target } })));`
  and the same with `shopify:section:unload` → `kodza:destroy`.

### React / Next.js

- Files, side by side (e.g. in `components/kodza/`): `AddToCart.tsx` (below), the CSS block under Code saved as `add-to-cart.css` and the JS block as `add-to-cart.js`, both as they are. The HTML block is already inside the component: skip it.
- Use it: `import { AddToCart } from '@/components/kodza/AddToCart';` then `<AddToCart>0</AddToCart>`. Props: `count` (`data-count`: "0"), `vars` (the `--kz-…` variables listed under API, e.g. `vars={{ '--kz-add-to-cart-bg': … }}`), `children` (the text, plain), `onAdd` (the `kodza:add` event), `className`, `style` and the other props of its `<a>` (`onClick`, `aria-…`).
- Next.js App Router: it is a Client Component already (`'use client'`). Pages Router: Next.js takes global CSS only in `pages/_app`, so move the `import './add-to-cart.css'` line there.
- Safe under StrictMode, client-side navigation and prop changes: when a prop changes, the `key` gives React a fresh element, `kodza:destroy` stops the script on the old one and `kodza:init` starts it on the new one.
- Built from your data (tabs, rows, options)? Add what the markup is made of to the `key`, as plain values (ids, text, numbers). What the visitor changes (the open tab, the sort, what they type) is the script's: follow it with `onClick` or `onInput` on the root, and change it from your code as a visitor would (click the tab; set the field's value, then dispatch a bubbling `input` event). Fields stay uncontrolled (`defaultValue`, `name`).

```tsx
'use client';
// Kodza — Add to Cart, for React. From https://kodza.dev/components/add-to-cart/
// Kodza License: free to use, client work included. Not to resell or redistribute, ported or not: https://kodza.dev/docs/#print-license
// Next to this file: add-to-cart.css and add-to-cart.js, the component's CSS and JS from Kodza, as they are.
// Yours to edit: the markup is plain JSX below.
// The script changes this markup once React has rendered it (it adds layers, splits text, moves
// nodes), so React must not patch it afterwards. When a prop changes, the key gives React a fresh
// element: kodza:destroy stops the script on the old one, kodza:init starts it on the new one.
// Built from your data (tabs, rows, options)? Put what the markup is made of in the key, as plain
// values (ids, text, numbers): a change starts the script again on fresh markup. What the visitor
// changes (the open tab, the sort, what they type) is the script's: keep it out of the key, follow
// it with onClick or onInput on the root, and change it from your code as a visitor would (click
// the tab; set the field's value, then dispatch a bubbling input event).
import { useRef, useEffect, type ComponentPropsWithoutRef, type ComponentRef, type CSSProperties } from 'react';
import './add-to-cart.css';

export type AddToCartProps = Omit<ComponentPropsWithoutRef<'a'>, "children" | "vars" | "count" | "onAdd"> & {
  /** data-count on the root (default: 0) */
  count?: "0";
  /** Settings, as CSS variables on the root */
  vars?: {
    /** default: #0a0a0a */
    "--kz-add-to-cart-bg"?: string | number;
    /** default: #ffffff */
    "--kz-add-to-cart-fg"?: string | number;
    /** default: 52px */
    "--kz-add-to-cart-height"?: string | number;
    /** default: 28px */
    "--kz-add-to-cart-pad-x"?: string | number;
    /** default: cubic-bezier(0.22, 1, 0.36, 1) */
    "--kz-add-to-cart-ease"?: string | number;
    /** default: #0a0a0a */
    "--kz-add-to-cart-ink"?: string | number;
    /** default: #ffffff */
    "--kz-add-to-cart-paper"?: string | number;
    /** default: 44px */
    "--kz-add-to-cart-cart-size"?: string | number;
    /** default: rgba(10, 10, 10, 0.06) */
    "--kz-add-to-cart-cart-hover"?: string | number;
  };
  /** The text, plain: the script reads it and rebuilds the markup around it */
  children?: string;
  /** "kodza:add", fired by the script (bubbles from the root) */
  onAdd?: (event: CustomEvent) => void;
  className?: string;
};

export function AddToCart({ count = "0", vars, children = "0", onAdd, className, style, ...rest }: AddToCartProps) {
  const ref = useRef<ComponentRef<'a'>>(null);
  const classes = ["kodza-add-to-cart__cart", className].filter(Boolean).join(' ');
  // Everything the markup is made of: when it changes, React gets a fresh element (see the top)
  const key = JSON.stringify([classes, count, vars, children, style, rest]);

  // Starts the script on this element once React has rendered it, stops it when it goes
  useEffect(() => {
    const root = ref.current;
    let live = true;
    // @ts-ignore: a plain script, no types to find
    import('./add-to-cart.js').then(() => {
      if (live) document.dispatchEvent(new CustomEvent('kodza:init', { detail: { root } }));
    });
    return () => {
      live = false;
      document.dispatchEvent(new CustomEvent('kodza:destroy', { detail: { root } }));
    };
  }, [key]);

  useEffect(() => {
    const root = ref.current;
    if (!root || !onAdd) return;
    const listener = (event: Event) => onAdd(event as CustomEvent);
    root.addEventListener("kodza:add", listener);
    return () => root.removeEventListener("kodza:add", listener);
  }, [onAdd, key]);

  return (
    <a href="/cart/" aria-label="Cart, 0 items" key={key} {...rest} className={classes} data-count={count} style={{ ...vars, ...style } as CSSProperties} ref={ref}>
      <svg className="kodza-add-to-cart__bag" viewBox="0 0 24 24" aria-hidden="true">
        <path d="M5.2 8.2h13.6l-1 11a2 2 0 0 1-2 1.8H8.2a2 2 0 0 1-2-1.8z" />
        <path d="M9 8.2V6.8a3 3 0 0 1 6 0v1.4" />
      </svg>
      {' '}
      <span className="kodza-add-to-cart__count" aria-hidden="true">{children}</span>
    </a>
  );
}
```

## Code

```html
<a class="kodza-add-to-cart__cart" href="/cart/" aria-label="Cart, 0 items" data-count="0">
  <svg class="kodza-add-to-cart__bag" viewBox="0 0 24 24" aria-hidden="true"><path d="M5.2 8.2h13.6l-1 11a2 2 0 0 1-2 1.8H8.2a2 2 0 0 1-2-1.8z" /><path d="M9 8.2V6.8a3 3 0 0 1 6 0v1.4" /></svg>
  <span class="kodza-add-to-cart__count" aria-hidden="true">0</span>
</a>

<button class="kodza-add-to-cart" type="button">
  <span class="kodza-add-to-cart__label">
    <span>Add to cart</span>
    <span aria-hidden="true"><svg viewBox="0 0 24 24"><path d="M6 12.5l4 4 8-9" pathLength="1" /></svg>Added</span>
    <span aria-hidden="true"><svg viewBox="0 0 24 24"><circle cx="12" cy="12" r="8.5" /><path d="M12 7.8v5" /><path d="M12 16.2v.01" /></svg>Try again</span>
  </span>
</button>
```

```css
/* Kodza License: free to use, client work included. Not to resell or redistribute, ported or not: https://kodza.dev/docs/#print-license */
/* Kodza — Add to Cart
   Two pieces: the button that goes on each product, and the cart icon that goes in the header.
   Clicked, the button rolls to "Added" with a tick, a copy of the product picture flies in an
   arc into the bag, and the count rolls up by one, digit by digit. The count lives in the
   cart's data-count: set it from your code (cart fragments, a page load) and it rolls too.
   From your code: listen to "kodza:add" and pass your request to event.detail.wait(promise);
   if it fails, the count rolls back and the button says "Try again".
   Everything is tuned with the --kz-add-to-cart-* variables. */
.kodza-add-to-cart {
  --kz-add-to-cart-bg: #0a0a0a;
  --kz-add-to-cart-fg: #ffffff;
  --kz-add-to-cart-height: 52px;
  --kz-add-to-cart-pad-x: 28px;
  --kz-add-to-cart-ease: cubic-bezier(0.22, 1, 0.36, 1);

  position: relative;
  display: inline-grid;
  align-items: center;
  height: var(--kz-add-to-cart-height);
  padding: 0 var(--kz-add-to-cart-pad-x);
  border: 0;
  border-radius: 999px;
  background: var(--kz-add-to-cart-bg);
  color: var(--kz-add-to-cart-fg);
  font: inherit;
  font-weight: 500;
  letter-spacing: -0.01em;
  white-space: nowrap;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  transition: transform 0.25s var(--kz-add-to-cart-ease);
}

.kodza-add-to-cart:active {
  transform: scale(0.97);
}

.kodza-add-to-cart:focus-visible {
  outline: 2px solid var(--kz-add-to-cart-bg);
  outline-offset: 3px;
}

.kodza-add-to-cart--soft {
  --kz-add-to-cart-bg: rgba(10, 10, 10, 0.07);
  --kz-add-to-cart-fg: #0a0a0a;
}

.kodza-add-to-cart--soft:focus-visible {
  outline-color: var(--kz-add-to-cart-fg);
}

/* The words: three in one cell, so the width is the widest one's and never moves */
.kodza-add-to-cart__label {
  display: inline-grid;
  grid-area: 1 / 1;
  overflow: hidden;
  padding-block: 0.15em;
}

.kodza-add-to-cart__label > span {
  display: inline-flex;
  grid-area: 1 / 1;
  align-items: center;
  justify-self: center;
  gap: 8px;
}

.kodza-add-to-cart__label > span:not(:first-child) {
  transform: translateY(110%);
}

.kodza-add-to-cart__label svg {
  display: block;
  flex: none;
  width: 18px;
  height: 18px;
  margin-left: -4px;
  overflow: visible;
  fill: none;
  stroke: currentColor;
  stroke-width: 2.2;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* The tick draws itself once "Added" is in */
.kodza-add-to-cart__label > span:nth-child(2) path {
  stroke-dasharray: 1;
  stroke-dashoffset: 1;
}

.kodza-add-to-cart[data-state="added"] .kodza-add-to-cart__label > span:nth-child(2) path {
  stroke-dashoffset: 0;
  transition: stroke-dashoffset 0.38s var(--kz-add-to-cart-ease) 0.16s;
}

.kodza-add-to-cart__label > span:nth-child(3) svg {
  stroke-width: 1.8;
}

.kodza-add-to-cart__label > span:nth-child(3) path {
  stroke-width: 2.2;
}

/* The cart: a round icon link with its count on the corner */
.kodza-add-to-cart__cart {
  --kz-add-to-cart-ink: #0a0a0a;
  --kz-add-to-cart-paper: #ffffff;
  --kz-add-to-cart-cart-size: 44px;
  --kz-add-to-cart-cart-hover: rgba(10, 10, 10, 0.06);

  position: relative;
  display: inline-grid;
  place-items: center;
  width: var(--kz-add-to-cart-cart-size);
  height: var(--kz-add-to-cart-cart-size);
  border-radius: 999px;
  color: var(--kz-add-to-cart-ink);
  text-decoration: none;
  -webkit-tap-highlight-color: transparent;
  transition: background-color 0.2s ease;
}

.kodza-add-to-cart__cart:hover {
  background: var(--kz-add-to-cart-cart-hover);
}

.kodza-add-to-cart__cart:focus-visible {
  outline: 2px solid var(--kz-add-to-cart-ink);
  outline-offset: 2px;
}

.kodza-add-to-cart__bag {
  display: block;
  width: 22px;
  height: 22px;
  overflow: visible;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.6;
  stroke-linecap: round;
  stroke-linejoin: round;
  transform-origin: 50% 85%;
}

/* The count: hidden at zero, pops in with the first item */
.kodza-add-to-cart__count {
  position: absolute;
  top: 3px;
  left: calc(50% + 3px);
  display: inline-flex;
  justify-content: center;
  box-sizing: border-box;
  min-width: 18px;
  height: 18px;
  padding: 0 5px;
  overflow: hidden;
  border-radius: 999px;
  background: var(--kz-add-to-cart-ink);
  color: var(--kz-add-to-cart-paper);
  font-size: 11px;
  font-weight: 600;
  line-height: 18px;
  letter-spacing: 0;
  font-variant-numeric: tabular-nums;
  pointer-events: none;
  transition: transform 0.45s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.2s ease;
}

.kodza-add-to-cart__cart[data-count="0"] .kodza-add-to-cart__count {
  opacity: 0;
  transform: scale(0.3);
  transition: transform 0.25s cubic-bezier(0.65, 0, 0.35, 1), opacity 0.2s ease 0.05s;
}

/* One cell per digit, so only the digits that change roll */
.kodza-add-to-cart__digit {
  position: relative;
  display: block;
  height: 18px;
  overflow: hidden;
}

.kodza-add-to-cart__digit > span {
  display: block;
}

.kodza-add-to-cart__digit > span + span {
  position: absolute;
  top: 0;
  left: 0;
}

.kodza-add-to-cart__sr {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

@media (prefers-reduced-motion: reduce) {
  .kodza-add-to-cart,
  .kodza-add-to-cart__count,
  .kodza-add-to-cart__label path {
    transition-duration: 0.01ms !important;
    transition-delay: 0s !important;
  }
}

/* Theming example — on a dark background:
.dark-section .kodza-add-to-cart {
  --kz-add-to-cart-bg: #ffffff;
  --kz-add-to-cart-fg: #0a0a0a;
}
.dark-section .kodza-add-to-cart__cart {
  --kz-add-to-cart-ink: #ffffff;
  --kz-add-to-cart-paper: #0a0a0a;
  --kz-add-to-cart-cart-hover: rgba(255, 255, 255, 0.1);
}
*/

/* kodza-guard 7903578edcb7 — generated by Kodza, do not edit.
   Theme guard: keeps a site's own CSS (WordPress themes, Bootstrap, CSS resets…) off this
   component. :not(#_) is always true and weighs as much as an id, so these lines win over
   theme rules made of classes and tags. Customise the component through its --kz-* variables. */

/* What the browser gives, where the component sets it only in some states: at the lowest weight, so its own rules below put it back */

:where(.kodza-add-to-cart__cart):not(#_) {
  outline: revert;
  background-color: revert;
  background-image: revert;
  outline-offset: revert;
}

:where(.kodza-add-to-cart):not(#_) {
  outline: revert;
  outline-offset: revert;
}

/* What the browser gives, on everything the component leaves to it */

.kodza-add-to-cart__cart:not(#_) {
  border: revert;
  padding: revert;
  list-style: revert;
  box-sizing: revert;
  box-shadow: revert;
  appearance: revert;
  max-height: revert;
  font-family: revert;
  font-size: revert;
  font-weight: revert;
  font-style: revert;
  line-height: revert;
  letter-spacing: revert;
  text-transform: revert;
  text-underline-offset: revert;
  text-align: revert;
  text-indent: revert;
  text-shadow: revert;
  vertical-align: revert;
}

.kodza-add-to-cart__bag:not(#_) {
  border: revert;
  margin: revert;
  padding: revert;
  border-radius: revert;
  outline: revert;
  text-decoration: revert;
  transition: revert;
  list-style: revert;
  box-sizing: revert;
  float: revert;
  position: revert;
  background-color: revert;
  background-image: revert;
  box-shadow: revert;
  outline-offset: revert;
  appearance: revert;
  max-width: revert;
  max-height: revert;
  color: revert;
  font-family: revert;
  font-size: revert;
  font-weight: revert;
  font-style: revert;
  line-height: revert;
  letter-spacing: revert;
  text-transform: revert;
  text-underline-offset: revert;
  text-align: revert;
  text-indent: revert;
  text-shadow: revert;
  vertical-align: revert;
}

.kodza-add-to-cart:not(#_) {
  text-decoration: revert;
  list-style: revert;
  box-sizing: revert;
  box-shadow: revert;
  appearance: revert;
  max-height: revert;
  text-transform: revert;
  text-underline-offset: revert;
  text-align: revert;
  text-indent: revert;
  text-shadow: revert;
  vertical-align: revert;
  min-height: revert;
}

.kodza-add-to-cart__label:not(#_),
.kodza-add-to-cart__label span:where(:not([class*="kodza-"])):not(#_) {
  box-sizing: revert;
}

.kodza-add-to-cart__label svg:where(:not([class*="kodza-"])):not(#_) {
  border: revert;
  padding: revert;
  border-radius: revert;
  outline: revert;
  text-decoration: revert;
  transition: revert;
  list-style: revert;
  box-sizing: revert;
  float: revert;
  position: revert;
  margin-top: revert;
  margin-right: revert;
  margin-bottom: revert;
  background-color: revert;
  background-image: revert;
  box-shadow: revert;
  outline-offset: revert;
  appearance: revert;
  max-width: revert;
  max-height: revert;
  color: revert;
  font-family: revert;
  font-size: revert;
  font-weight: revert;
  font-style: revert;
  line-height: revert;
  letter-spacing: revert;
  text-transform: revert;
  text-underline-offset: revert;
  text-align: revert;
  text-indent: revert;
  text-shadow: revert;
  vertical-align: revert;
}

/* The component's own rules, one step stronger: real buttons and fields, what it sets on tags themes style (links, lists, headings, images…), and the root width (a theme may narrow it, never widen it) */

.kodza-add-to-cart:not(#_) {
  position: relative;
  display: inline-grid;
  align-items: center;
  height: var(--kz-add-to-cart-height);
  padding: 0 var(--kz-add-to-cart-pad-x);
  border: 0;
  border-radius: 999px;
  background: var(--kz-add-to-cart-bg);
  color: var(--kz-add-to-cart-fg);
  font: inherit;
  font-weight: 500;
  letter-spacing: -0.01em;
  white-space: nowrap;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  transition: transform 0.25s var(--kz-add-to-cart-ease);
}

.kodza-add-to-cart:active:not(#_) {
  transform: scale(0.97);
}

.kodza-add-to-cart:focus-visible:not(#_) {
  outline: 2px solid var(--kz-add-to-cart-bg);
  outline-offset: 3px;
}

.kodza-add-to-cart__label svg:not(#_) {
  display: block;
  margin-left: -4px;
}

.kodza-add-to-cart__cart:not(#_) {
  position: relative;
  display: inline-grid;
  border-radius: 999px;
  color: var(--kz-add-to-cart-ink);
  text-decoration: none;
  transition: background-color 0.2s ease;
}

.kodza-add-to-cart__cart:hover:not(#_) {
  background: var(--kz-add-to-cart-cart-hover);
}

.kodza-add-to-cart__cart:focus-visible:not(#_) {
  outline: 2px solid var(--kz-add-to-cart-ink);
  outline-offset: 2px;
}

.kodza-add-to-cart__bag:not(#_) {
  display: block;
}

@media (prefers-reduced-motion: reduce) {
  .kodza-add-to-cart:not(#_) {
    transition-duration: 0.01ms !important;
    transition-delay: 0s !important;
  }
}
```

```js
// Kodza License: free to use, client work included. Not to resell or redistribute, ported or not: https://kodza.dev/docs/#print-license
// Kodza — Add to Cart
// The button rolls to "Added", flies a copy of the product picture in an arc into the bag and
// adds one to the cart; the cart rolls its count digit by digit whenever data-count changes,
// from the button or from your code. "kodza:add" bubbles from the button and can be cancelled:
// pass your request to event.detail.wait(promise), and if it rejects the count rolls back and
// the button says "Try again". data-image (a selector) picks the picture, data-cart the carts,
// data-quantity how many it adds.
(() => {
  const SELECTOR = '.kodza-add-to-cart, .kodza-add-to-cart__cart';
  const CART = '.kodza-add-to-cart__cart';
  const reduceMotion = window.matchMedia('(prefers-reduced-motion: reduce)').matches;
  const ease = 'cubic-bezier(0.22, 1, 0.36, 1)';
  const STATES = ['idle', 'added', 'failed'];
  const countOf = (cart) => Math.max(0, parseInt(cart.dataset.count, 10) || 0);
  const format = (n) => new Intl.NumberFormat(document.documentElement.lang || undefined).format(n);

  // The cart: its count follows data-count, rolling only the digits that change (999 → 1,000
  // carries), and the bag gives a little bump each time something lands in it
  function mountCart(cart, signal) {
    const count = cart.querySelector('.kodza-add-to-cart__count');
    const bag = cart.querySelector('.kodza-add-to-cart__bag');
    let shown = countOf(cart);

    const label = (n) => {
      const text = cart.getAttribute('aria-label');
      if (!text) return;
      cart.setAttribute('aria-label', text.replace(/\d[\d.,  ]*/, format(n)).replace(/\bitems?\b/, n === 1 ? 'item' : 'items'));
    };

    // Old and new numbers aligned on the right: a digit that changes rolls (up when the count
    // grows, down when it shrinks), the units first, and a digit that appears opens its room
    const draw = (from, to) => {
      const a = format(from);
      const b = format(to);
      const n = Math.max(a.length, b.length);
      const was = a.padStart(n);
      const now = b.padStart(n);
      const k = to > from ? 1 : -1;
      count.textContent = '';
      for (let i = 0; i < n; i++) {
        const cell = Object.assign(document.createElement('span'), { className: 'kodza-add-to-cart__digit' });
        const next = Object.assign(document.createElement('span'), { textContent: now[i].trim() });
        cell.append(next);
        count.append(cell);
        if (was[i] === now[i] || reduceMotion) continue;
        const old = Object.assign(document.createElement('span'), { textContent: was[i].trim() });
        cell.append(old);
        const timing = { duration: 460, delay: (n - 1 - i) * 60, easing: ease };
        next.animate([{ transform: `translateY(${100 * k}%)` }, { transform: 'none' }], { ...timing, fill: 'backwards' });
        const leave = old.animate([{ transform: 'none' }, { transform: `translateY(${-100 * k}%)` }], { ...timing, fill: 'forwards' });
        if (was[i] === ' ') cell.animate([{ width: '0px' }, { width: `${cell.offsetWidth}px` }], timing);
        if (now[i] === ' ') cell.animate([{ width: `${old.offsetWidth}px` }, { width: '0px' }], { ...timing, fill: 'forwards' });
        // Once out of sight the old digit goes, and so does a cell left empty
        leave.finished.then(() => (now[i] === ' ' ? cell : old).remove(), () => {});
      }
    };

    const observer = new MutationObserver(() => {
      const next = countOf(cart);
      if (next === shown) return;
      const from = shown;
      shown = next;
      label(next);
      if (!count) return;
      // From zero the badge pops in with its number; to zero it shrinks away with the last one
      if (from === 0) count.textContent = format(next);
      else if (next > 0) draw(from, next);
      if (reduceMotion || next < from) return;
      bag?.animate([
        { transform: 'none' },
        { transform: 'translateY(1.5px) scale(1.08, 0.9)', offset: 0.3 },
        { transform: 'translateY(-1px) scale(0.97, 1.04)', offset: 0.65 },
        { transform: 'none' },
      ], { duration: 520, easing: 'ease-out' });
      if (from > 0) count.animate([{ transform: 'none' }, { transform: 'translateY(-3px) scale(1.12)', offset: 0.35 }, { transform: 'none' }], { duration: 420, easing: 'ease-out' });
    });
    observer.observe(cart, { attributes: true, attributeFilter: ['data-count'] });
    signal.addEventListener('abort', () => observer.disconnect());
    if (count) count.textContent = format(shown);
    label(shown);
  }

  // The button: words rolling between three states, the flight, and the request it waits for
  function mountButton(button, signal) {
    const words = [...button.querySelectorAll('.kodza-add-to-cart__label > span')];
    if (words.length < 3) return;
    // The spoken status sits right after the button, and leaves with it
    const status = Object.assign(document.createElement('span'), { className: 'kodza-add-to-cart__sr' });
    status.setAttribute('role', 'status');
    button.after(status);
    const flights = new Set();
    let index = 0;
    let rest = 0;
    let sayTimer = 0;

    // The new words come up from below, the old ones leave through the top
    const roll = (next) => {
      if (next === index) return;
      const old = words[index];
      const now = words[next];
      index = next;
      words.forEach((word, i) => {
        word.getAnimations().forEach((a) => a.cancel());
        word.style.transform = i === next ? 'none' : 'translateY(110%)';
        if (i === next) word.removeAttribute('aria-hidden');
        else word.setAttribute('aria-hidden', 'true');
      });
      if (reduceMotion) return;
      const timing = { duration: 520, easing: ease };
      old.animate([{ transform: 'none' }, { transform: 'translateY(-110%)' }], timing);
      now.animate([{ transform: 'translateY(110%)' }, { transform: 'none' }], timing);
    };

    const settle = (state) => {
      roll(STATES.indexOf(state));
      button.dataset.state = state;
      clearTimeout(rest);
      if (state !== 'idle') rest = setTimeout(() => settle('idle'), state === 'added' ? 2400 : 3200);
    };

    // Emptied first, then filled: a screen reader reads the same message twice in a row too
    const say = (message) => {
      status.textContent = '';
      clearTimeout(sayTimer);
      sayTimer = setTimeout(() => { status.textContent = message(); }, 60);
    };

    // The carts it adds to: data-cart, or the ones nearest to the button in the page
    const cartsFor = () => {
      if (button.dataset.cart) return [...document.querySelectorAll(button.dataset.cart)];
      for (let el = button.parentElement; el; el = el.parentElement) {
        const found = el.querySelectorAll(CART);
        if (found.length) return [...found];
      }
      return [];
    };

    // The picture that flies: data-image, or the first one shown around the button, but never
    // past a block that holds other buttons (a grid of products)
    const pictureFor = () => {
      const wanted = button.dataset.image;
      for (let el = button.parentElement, depth = 0; el && el !== document.documentElement; el = el.parentElement, depth++) {
        if (wanted) {
          const found = el.querySelector(wanted);
          if (found) return found;
          continue;
        }
        if (depth > 3 || el.querySelectorAll('.kodza-add-to-cart').length > 1) return null;
        const img = [...el.querySelectorAll('img')].find((image) => !image.closest(CART) && image.getBoundingClientRect().width > 0);
        if (img) return img;
      }
      return null;
    };

    const visible = (el) => {
      const r = el.getBoundingClientRect();
      return r.width > 0 && r.bottom > 0 && r.top < innerHeight;
    };

    // A picture mostly scrolled out of sight (a phone, the button far below it) would fly in from
    // nowhere: then the dot leaves the button instead
    const seen = (el) => {
      const r = el?.getBoundingClientRect();
      return r && r.width > 0 && Math.min(r.bottom, innerHeight) - Math.max(r.top, 0) > r.height / 4;
    };

    // A copy of the picture lifts, flies in an arc above the cart and drops into the bag,
    // turning into a small round on the way. Without a picture, a dot leaves the button.
    const fly = (picture, cart) => {
      const bag = cart.querySelector('.kodza-add-to-cart__bag') || cart;
      const own = button.getBoundingClientRect();
      const start = picture ? picture.getBoundingClientRect() : new DOMRect(own.left + own.width / 2 - 7, own.top + own.height / 2 - 7, 14, 14);
      const end = bag.getBoundingClientRect();
      const { width: w, height: h } = start;
      const side = Math.min(w, h);
      const radius = picture ? parseFloat(getComputedStyle(picture).borderTopLeftRadius) || 0 : 7;
      const p0 = { x: start.left + w / 2, y: start.top + h / 2 };
      const p2 = { x: end.left + end.width / 2, y: end.top + end.height * 0.42 };
      const dx = p2.x - p0.x;
      const lift = Math.min(140, Math.max(36, Math.hypot(dx, p2.y - p0.y) * 0.22));
      const p1 = { x: p0.x + dx * 0.62, y: Math.min(p0.y, p2.y) - lift };
      // It ends about the size of the bag, whatever scale the page is drawn at
      const small = Math.min(1, (end.width * 0.9) / side);

      const wrap = document.createElement('span');
      const pic = document.createElement('span');
      wrap.setAttribute('aria-hidden', 'true');
      Object.assign(wrap.style, {
        position: 'fixed', left: `${start.left}px`, top: `${start.top}px`, width: `${w}px`, height: `${h}px`,
        display: 'block', margin: '0', padding: '0', zIndex: '2147483000', pointerEvents: 'none',
        filter: 'drop-shadow(0 10px 14px rgba(10, 10, 10, 0.22))',
      });
      Object.assign(pic.style, {
        display: 'block', width: '100%', height: '100%', margin: '0',
        background: picture ? `center / cover no-repeat url("${(picture.currentSrc || picture.src).replace(/"/g, '%22')}")` : getComputedStyle(button).backgroundColor,
      });
      wrap.append(pic);
      document.body.append(wrap);

      // Sampled along the curve: a short lift, then the flight, sped up in the middle
      const LIFT = 140;
      const TRAVEL = 720;
      const at = LIFT / (LIFT + TRAVEL);
      const clip = (c) => `inset(${((h - side) / 2) * c}px ${((w - side) / 2) * c}px round ${radius + (side / 2 - radius) * c}px)`;
      const frames = [
        { offset: 0, transform: 'none', clipPath: clip(0), opacity: 1, easing: 'ease-out' },
        { offset: at, transform: 'translateY(-6px) scale(1.04)', clipPath: clip(0), opacity: 1 },
      ];
      for (let i = 1; i <= 24; i++) {
        const u = i / 24;
        const p = (1 - Math.cos(Math.PI * u)) / 2;
        const x = (1 - p) ** 2 * p0.x + 2 * (1 - p) * p * p1.x + p ** 2 * p2.x - p0.x;
        const y = (1 - p) ** 2 * p0.y + 2 * (1 - p) * p * p1.y + p ** 2 * p2.y - p0.y - 6 * (1 - u);
        const shrink = 1 - (1 - Math.min(1, u / 0.8)) ** 2;
        const scale = 1.04 + (small - 1.04) * shrink;
        const tilt = 7 * Math.sign(dx) * Math.sin(Math.PI * u);
        frames.push({
          offset: at + (1 - at) * u,
          transform: `translate(${x}px, ${y}px) rotate(${tilt}deg) scale(${u > 0.86 ? scale * (1 - ((u - 0.86) / 0.14) * 0.55) : scale})`,
          clipPath: clip(Math.min(1, u / 0.45)),
          opacity: u > 0.86 ? 1 - (u - 0.86) / 0.14 : 1,
        });
      }
      const flight = wrap.animate(frames, { duration: LIFT + TRAVEL, fill: 'forwards' });
      const done = () => {
        flights.delete(stop);
        wrap.remove();
      };
      // A refused request while it is still in the air: it falls away instead of landing
      const drop = () => {
        flight.pause();
        const now = getComputedStyle(wrap).transform;
        wrap.getAnimations().forEach((a) => a.cancel());
        wrap.animate([{ transform: now, opacity: 1 }, { transform: `${now === 'none' ? '' : now} translateY(24px)`, opacity: 0 }], { duration: 280, easing: 'ease-in', fill: 'forwards' }).finished.then(done, done);
      };
      const stop = () => {
        flight.cancel();
        done();
      };
      flights.add(stop);
      return { landed: flight.finished.then(() => done()), drop };
    };

    // Adds to every cart it found (a header and its mobile copy stay in step)
    const add = (carts, quantity) => carts.forEach((cart) => {
      cart.dataset.count = String(Math.max(0, countOf(cart) + quantity));
    });

    button.addEventListener('click', () => {
      const quantity = Math.max(1, parseInt(button.dataset.quantity, 10) || 1);
      let request = null;
      const event = new CustomEvent('kodza:add', {
        bubbles: true,
        cancelable: true,
        detail: { quantity, wait: (promise) => { request = Promise.resolve(promise); } },
      });
      if (!button.dispatchEvent(event)) return;
      const carts = cartsFor();
      // It flies to a cart in sight. None on screen (a header scrolled away): nothing flies off into
      // nowhere, the button says it and the count changes
      const target = carts.find(visible);
      let landed = false;
      let failed = false;
      const land = () => {
        if (failed || signal.aborted) return;
        landed = true;
        add(carts, quantity);
        say(() => [words[1].textContent.trim(), (target || carts[0])?.getAttribute('aria-label')].filter(Boolean).join('. ') + '.');
      };
      settle('added');
      const picture = pictureFor();
      const flight = !reduceMotion && target ? fly(seen(picture) ? picture : null, target) : null;
      if (flight) flight.landed.then(land, () => {});
      else land();
      request?.catch(() => {
        if (signal.aborted) return;
        failed = true;
        if (landed) add(carts, -quantity);
        else flight?.drop();
        settle('failed');
        say(() => `${words[2].textContent.trim()}.`);
      });
    }, { signal });

    button.dataset.state = 'idle';
    signal.addEventListener('abort', () => {
      clearTimeout(rest);
      clearTimeout(sayTimer);
      flights.forEach((stop) => stop());
      status.remove();
    });
  }

  // One instance per button and per cart, each with its own state. Everything it starts is
  // tied to `signal`, so kodza:destroy stops it all.
  function mount(root, signal) {
    if (root.matches(CART)) mountCart(root, signal);
    else mountButton(root, signal);
  }

  // Kodza lifecycle, the same in every component: `kodza:init` starts the instances inside
  // event.detail.root (the whole page by default), `kodza:destroy` stops them and puts their
  // markup back. For themes and apps that swap content without a page load. Each running root
  // keeps its markup as written under KODZA, shared by every Kodza script on the page: a Kodza
  // component inside another one is saved as written, not half-started, and stopped with it.
  const KODZA = Symbol.for('kodza');
  const instances = new WeakMap();
  const find = (scope = document) => [scope, ...scope.querySelectorAll(SELECTOR)].filter((el) => el.matches?.(SELECTOR));
  const attrsOf = (el) => [...el.attributes].map((a) => [a.name, a.value]);
  const put = (el, saved) => {
    [...el.attributes].forEach((a) => el.removeAttribute(a.name));
    saved.attrs.forEach(([name, value]) => el.setAttribute(name, value));
    el.innerHTML = saved.html;
  };
  // The markup inside a root as written: Kodza components already running in it give back their own
  const written = (root) => {
    const all = [...root.querySelectorAll('*')];
    if (!all.some((el) => el[KODZA])) return root.innerHTML;
    const copy = root.cloneNode(true);
    const twins = copy.querySelectorAll('*');
    let last = null;
    all.forEach((el, i) => {
      if (!el[KODZA] || last?.contains(el)) return;
      last = el;
      put(twins[i], el[KODZA]);
    });
    return copy.innerHTML;
  };
  const init = (scope) => find(scope).forEach((root) => {
    if (root.classList.contains('is-ready')) return; // already running, maybe from another copy of this script
    const controller = new AbortController();
    const saved = { html: written(root), attrs: attrsOf(root), stop: () => destroy(root) };
    instances.set(root, { controller, saved });
    root[KODZA] = saved;
    mount(root, controller.signal);
    root.classList.add('is-ready');
  });
  const destroy = (scope) => find(scope).forEach((root) => {
    const instance = instances.get(root);
    if (!instance) return;
    instances.delete(root);
    // The Kodza components running inside it stop first: once its markup is put back, their own
    // script could not find them any more
    root.querySelectorAll('*').forEach((el) => el[KODZA]?.stop());
    instance.controller.abort();
    delete root[KODZA];
    put(root, instance.saved);
  });
  document.addEventListener('kodza:init', (event) => init(event.detail?.root));
  document.addEventListener('kodza:destroy', (event) => destroy(event.detail?.root));
  init();
  // Loaded in <head>, the script runs before the markup exists: once more when it is parsed
  if (document.readyState === 'loading') document.addEventListener('DOMContentLoaded', () => init(), { once: true });
})();
```

Free to use, from Kodza (https://kodza.dev).