# Liquid fill radio

> Colour rises inside the circle like water, and its wavy surface keeps turning gently.

- Category: [Radio buttons](https://library.aimran.es/components/radios)
- Built with: HTML + CSS
- Live editor: https://library.aimran.es/blocks/uv-rd-liquid
- Library: AIMRAN Library (https://library.aimran.es), free, no sign-up, by Aimran Oukham

## Where to use it

A radio that fills up like a glass is a natural match for anything you drink or pour: choosing water, juice or coffee in a café ordering app, the milk for a latte or the size of a smoothie. It also fits a water tracker app. A liquid radio button in CSS with a two-colour gradient.

The wave keeps moving while an option is selected, so use it where there are only a few choices on screen. Pick two shades of the same colour for the gradient; it looks more like real liquid that way.

## Code

### HTML

```html
<div class="uv-rdl"><label><input type="radio" name="rdl" checked><span class="rb"><i></i></span>Water</label><label><input type="radio" name="rdl"><span class="rb"><i></i></span>Juice</label><label><input type="radio" name="rdl"><span class="rb"><i></i></span>Coffee</label></div>
```

### CSS

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

.uv-rdl {
  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-direction: column;
  gap: .9em;
}

.uv-rdl label {
  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: inline-flex;
  align-items: center;
  gap: .7em;
  cursor: pointer;
  user-select: none;
  font-weight: 500;
}

.uv-rdl input {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
  pointer-events: none;
}

.uv-rdl .rb {
  position: relative;
  display: block;
  width: 1.5em;
  height: 1.5em;
  border-radius: 50%;
  overflow: hidden;
  box-shadow: inset 0 0 0 2px color-mix(in srgb,var(--fg) 20%,transparent);
  transition: box-shadow calc(0.3s / var(--k)) cubic-bezier(.25,.1,.25,1);
}

.uv-rdl i {
  position: absolute;
  left: -50%;
  bottom: -100%;
  width: 200%;
  height: 100%;
  background: linear-gradient(180deg,var(--c2),var(--c1));
  border-radius: 42% 44% 0 0 / 22% 20% 0 0;
  transition: bottom calc(0.55s / var(--k)) cubic-bezier(.25,.1,.25,1);
}

.uv-rdl label:hover .rb {
  box-shadow: inset 0 0 0 2px var(--c1);
}

.uv-rdl input:checked + .rb {
  box-shadow: inset 0 0 0 2px var(--c1);
}

.uv-rdl input:checked + .rb i {
  bottom: -10%;
  animation: uv-rdl calc(2.6s / var(--k)) linear infinite;
}

@keyframes uv-rdl {
  to {
    transform: rotate(360deg);
  }
}
```

### React

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

const css = `
.uv-rdl {
  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-direction: column;
  gap: .9em;
}

.uv-rdl label {
  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: inline-flex;
  align-items: center;
  gap: .7em;
  cursor: pointer;
  user-select: none;
  font-weight: 500;
}

.uv-rdl input {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
  pointer-events: none;
}

.uv-rdl .rb {
  position: relative;
  display: block;
  width: 1.5em;
  height: 1.5em;
  border-radius: 50%;
  overflow: hidden;
  box-shadow: inset 0 0 0 2px color-mix(in srgb,var(--fg) 20%,transparent);
  transition: box-shadow calc(0.3s / var(--k)) cubic-bezier(.25,.1,.25,1);
}

.uv-rdl i {
  position: absolute;
  left: -50%;
  bottom: -100%;
  width: 200%;
  height: 100%;
  background: linear-gradient(180deg,var(--c2),var(--c1));
  border-radius: 42% 44% 0 0 / 22% 20% 0 0;
  transition: bottom calc(0.55s / var(--k)) cubic-bezier(.25,.1,.25,1);
}

.uv-rdl label:hover .rb {
  box-shadow: inset 0 0 0 2px var(--c1);
}

.uv-rdl input:checked + .rb {
  box-shadow: inset 0 0 0 2px var(--c1);
}

.uv-rdl input:checked + .rb i {
  bottom: -10%;
  animation: uv-rdl calc(2.6s / var(--k)) linear infinite;
}

@keyframes uv-rdl {
  to {
    transform: rotate(360deg);
  }
}
`;

export default function RdLiquid() {
  return (
    <>
      <style>{css}</style>
      <div
        style={{
          "--c1": "#0071e3",
          "--c2": "#8ec5ff",
          "--s": "16px",
          "--k": "1",
          "--fg": "#1d1d1f",
          "--bg": "#f5f5f7",
        } as CSSProperties}
      >
        <div className="uv-rdl"><label><input type="radio" name="rdl" checked={true} /><span className="rb"><i></i></span>Water</label><label><input type="radio" name="rdl" /><span className="rb"><i></i></span>Juice</label><label><input type="radio" name="rdl" /><span className="rb"><i></i></span>Coffee</label></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 “Liquid fill radio” block (Radio buttons) from AIMRAN Library to my project.

## What it is
Colour rises inside the circle like water, and its wavy surface keeps turning gently.

## 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-rdl {
  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-direction: column;
  gap: .9em;
}

.uv-rdl label {
  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: inline-flex;
  align-items: center;
  gap: .7em;
  cursor: pointer;
  user-select: none;
  font-weight: 500;
}

.uv-rdl input {
  position: absolute;
  opacity: 0;
  width: 0;
  height: 0;
  pointer-events: none;
}

.uv-rdl .rb {
  position: relative;
  display: block;
  width: 1.5em;
  height: 1.5em;
  border-radius: 50%;
  overflow: hidden;
  box-shadow: inset 0 0 0 2px color-mix(in srgb,var(--fg) 20%,transparent);
  transition: box-shadow calc(0.3s / var(--k)) cubic-bezier(.25,.1,.25,1);
}

.uv-rdl i {
  position: absolute;
  left: -50%;
  bottom: -100%;
  width: 200%;
  height: 100%;
  background: linear-gradient(180deg,var(--c2),var(--c1));
  border-radius: 42% 44% 0 0 / 22% 20% 0 0;
  transition: bottom calc(0.55s / var(--k)) cubic-bezier(.25,.1,.25,1);
}

.uv-rdl label:hover .rb {
  box-shadow: inset 0 0 0 2px var(--c1);
}

.uv-rdl input:checked + .rb {
  box-shadow: inset 0 0 0 2px var(--c1);
}

.uv-rdl input:checked + .rb i {
  bottom: -10%;
  animation: uv-rdl calc(2.6s / var(--k)) linear infinite;
}

@keyframes uv-rdl {
  to {
    transform: rotate(360deg);
  }
}
`;

export default function RdLiquid() {
  return (
    <>
      <style>{css}</style>
      <div
        style={{
          "--c1": "#0071e3",
          "--c2": "#8ec5ff",
          "--s": "16px",
          "--k": "1",
          "--fg": "#1d1d1f",
          "--bg": "#f5f5f7",
        } as CSSProperties}
      >
        <div className="uv-rdl"><label><input type="radio" name="rdl" checked={true} /><span className="rb"><i></i></span>Water</label><label><input type="radio" name="rdl" /><span className="rb"><i></i></span>Juice</label><label><input type="radio" name="rdl" /><span className="rb"><i></i></span>Coffee</label></div>
      </div>
    </>
  );
}
```

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