# Glass tab bar

> A floating glass tab bar where the active pill slides to the next tab and stretches on the way.

- Category: [Liquid Glass](https://library.aimran.es/components/liquid-glass)
- Built with: React + Motion
- Live editor: https://library.aimran.es/blocks/lg-tab-bar
- Library: AIMRAN Library (https://library.aimran.es), free, no sign-up, by Aimran Oukham

## Where to use it

Think of the bottom navigation of a mobile web app: home, explore, library and search in a podcast app, or menu, orders and profile in a food delivery PWA. This glass tab bar floats above the content, and the pill that marks the current tab stretches as it travels, like on iOS.

Four tabs is the sweet spot. With six the pill has little room to move and the labels start to feel cramped. Keep each label to one short word and let the icons do most of the talking.

## Code

### React (Motion)

```tsx
import { useState, type CSSProperties, type MouseEvent, type ReactNode } from "react";
import { motion } from "framer-motion";
import { Compass, Home, Library, Search } from "lucide-react";

type Wallpaper = "aurora" | "sunset" | "ocean" | "light";

const spring = { type: "spring" as const, stiffness: 400, damping: 30 };

const walls: Record<Wallpaper, { base: string; blobs: string[] }> = {
  aurora: { base: "#0b0b1a", blobs: ["#5b21b6", "#2563eb", "#ec4899"] },
  sunset: { base: "#1a0b14", blobs: ["#f97316", "#f43f5e", "#8b5cf6"] },
  ocean: { base: "#031a1f", blobs: ["#06b6d4", "#3b82f6", "#10b981"] },
  light: { base: "#f8fafc", blobs: ["#fed7aa", "#ddd6fe", "#bae6fd"] },
};

const blobPositions = [
  ["-10%", "-15%"],
  ["45%", "5%"],
  ["5%", "50%"],
];

const grain = "url(\"data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E\")";

const glassCss = `
.lg-font {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Inter", sans-serif;
  -webkit-font-smoothing: antialiased;
}
.lg-glass {
  position: relative;
  overflow: hidden;
  background: rgba(255, 255, 255, var(--lg-a, 0.12));
  -webkit-backdrop-filter: blur(var(--lg-blur, 20px)) saturate(180%);
  backdrop-filter: blur(var(--lg-blur, 20px)) saturate(180%);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.5),
    inset 0 -1px 0 rgba(255, 255, 255, 0.1),
    inset 0 0 20px rgba(255, 255, 255, 0.08),
    0 8px 32px rgba(0, 0, 0, 0.18);
}
/* Borde de luz */
.lg-glass::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 2;
  padding: 1px;
  border-radius: inherit;
  pointer-events: none;
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.7), rgba(255, 255, 255, 0.05) 40%, rgba(255, 255, 255, 0.05) 60%, rgba(255, 255, 255, 0.4));
  mask: linear-gradient(#000 0 0) content-box exclude, linear-gradient(#000 0 0);
}
/* Reflejo que sigue al cursor (--x / --y los pone track()) */
.lg-glass::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  border-radius: inherit;
  pointer-events: none;
  opacity: var(--lg-hover, 0);
  transition: opacity 0.3s;
  background: radial-gradient(circle 140px at var(--x, 50%) var(--y, 0%), rgba(255, 255, 255, var(--lg-shine, 0.25)), transparent 70%);
}
.lg-glass:hover {
  --lg-hover: 1;
}
.lg-text {
  color: #fff;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.18);
}
.lg-light .lg-text {
  color: #1d1d1f;
  text-shadow: none;
}
@keyframes lg-drift {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33% { transform: translate(8%, -6%) scale(1.12); }
  66% { transform: translate(-6%, 7%) scale(0.94); }
}
`;

// Guarda la posición del cursor para el reflejo de .lg-glass::after
function track(e: MouseEvent<HTMLElement>) {
  const r = e.currentTarget.getBoundingClientRect();
  e.currentTarget.style.setProperty("--x", `${e.clientX - r.left}px`);
  e.currentTarget.style.setProperty("--y", `${e.clientY - r.top}px`);
}

interface StageProps {
  bg: Wallpaper;
  blur: number;
  opacity: number;
  shine: number;
  className?: string;
  children: ReactNode;
}

// Fondo de degradado animado sobre el que se ve el cristal
function Stage({
  bg,
  blur,
  opacity,
  shine,
  className = "relative h-[560px] w-full",
  children,
}: StageProps) {
  const light = bg === "light";
  const wall = walls[bg] ?? walls.aurora;
  const vars = {
    "--lg-blur": `${blur}px`,
    "--lg-a": light ? Math.min(0.6, opacity / 100 + 0.23) : opacity / 100,
    "--lg-shine": shine / 100,
  } as CSSProperties;

  return (
    <div
      className={`lg-font overflow-hidden rounded-[22px] ${className} ${light ? "lg-light" : ""}`}
      style={vars}
    >
      <style>{glassCss}</style>
      <div className="absolute inset-0 overflow-hidden" style={{ background: wall.base }}>
        <div className="absolute inset-0" style={{ filter: "blur(60px)" }}>
          {wall.blobs.map((color, i) => (
            <div
              key={i}
              className="absolute h-[75%] w-[75%] rounded-full"
              style={{
                left: blobPositions[i]?.[0],
                top: blobPositions[i]?.[1],
                background: `radial-gradient(circle, ${color} 0%, transparent 68%)`,
                opacity: light ? 1 : 0.9,
                animation: `lg-drift 20s ease-in-out ${-i * 6}s infinite`,
              }}
            />
          ))}
        </div>
        <div
          className="absolute inset-0"
          style={{ backgroundImage: grain, opacity: 0.04, mixBlendMode: "overlay" }}
        />
      </div>
      <div className="relative grid h-full w-full grid-cols-[100%] place-items-center p-4">{children}</div>
    </div>
  );
}

const tabs = [
  { icon: Home, label: "Home" },
  { icon: Compass, label: "Explore" },
  { icon: Library, label: "Library" },
  { icon: Search, label: "Search" },
];

interface GlassTabBarProps {
  bg?: Wallpaper;
  blur?: number;
  opacity?: number;
  shine?: number;
}

export default function GlassTabBar({
  bg = "aurora",
  blur = 20,
  opacity = 12,
  shine = 25,
}: GlassTabBarProps) {
  const glass = { bg, blur, opacity, shine };
  const [active, setActive] = useState(0);

  return (
    <Stage {...glass}>
      <div className="absolute inset-x-0 bottom-6 flex justify-center">
        <div onMouseMove={track} className="lg-glass flex rounded-full p-1">
          {tabs.map(({ icon: Icon, label }, i) => (
            <motion.button
              key={label}
              type="button"
              aria-pressed={active === i}
              onClick={() => setActive(i)}
              whileTap={{ scale: 0.92 }}
              transition={spring}
              className="lg-text relative z-[3] flex h-[54px] w-[74px] flex-col items-center justify-center gap-0.5"
            >
              {active === i && (
                // La key cambia en cada pulsación para repetir el estirón de la píldora
                <motion.span
                  key={`pill-${active}`}
                  layoutId="lg-tab-pill"
                  className="absolute inset-0 rounded-full"
                  initial={{ scaleX: 1 }}
                  animate={{ scaleX: [1, 1.15, 1] }}
                  transition={{
                    layout: spring,
                    scaleX: { duration: 0.45, ease: [0.25, 0.1, 0.25, 1] },
                  }}
                  style={{
                    background: "rgba(255,255,255,.22)",
                    boxShadow: "inset 0 1px 0 rgba(255,255,255,.55), 0 2px 8px rgba(0,0,0,.08)",
                  }}
                />
              )}
              <Icon className="relative h-[22px] w-[22px]" strokeWidth={1.75} />
              <span className="relative text-[11px] font-medium">{label}</span>
            </motion.button>
          ))}
        </div>
      </div>
    </Stage>
  );
}
```

## 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 “Glass tab bar” block (Liquid Glass) from AIMRAN Library to my project.

## What it is
A floating glass tab bar where the active pill slides to the next tab and stretches on the way.

## Chosen settings
- Text: "Home"
- Background: Aurora (other options: Sunset, Ocean, Light)
- Blur: 20px (from 4 to 40px)
- Glass opacity: 12% (from 4 to 40%)
- Shine: 25% (from 0 to 60%)

## 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 React + TypeScript, with framer-motion for the animation and lucide-react for the icons. 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 { useState, type CSSProperties, type MouseEvent, type ReactNode } from "react";
import { motion } from "framer-motion";
import { Compass, Home, Library, Search } from "lucide-react";

type Wallpaper = "aurora" | "sunset" | "ocean" | "light";

const spring = { type: "spring" as const, stiffness: 400, damping: 30 };

const walls: Record<Wallpaper, { base: string; blobs: string[] }> = {
  aurora: { base: "#0b0b1a", blobs: ["#5b21b6", "#2563eb", "#ec4899"] },
  sunset: { base: "#1a0b14", blobs: ["#f97316", "#f43f5e", "#8b5cf6"] },
  ocean: { base: "#031a1f", blobs: ["#06b6d4", "#3b82f6", "#10b981"] },
  light: { base: "#f8fafc", blobs: ["#fed7aa", "#ddd6fe", "#bae6fd"] },
};

const blobPositions = [
  ["-10%", "-15%"],
  ["45%", "5%"],
  ["5%", "50%"],
];

const grain = "url(\"data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='.9' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E\")";

const glassCss = `
.lg-font {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Inter", sans-serif;
  -webkit-font-smoothing: antialiased;
}
.lg-glass {
  position: relative;
  overflow: hidden;
  background: rgba(255, 255, 255, var(--lg-a, 0.12));
  -webkit-backdrop-filter: blur(var(--lg-blur, 20px)) saturate(180%);
  backdrop-filter: blur(var(--lg-blur, 20px)) saturate(180%);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.5),
    inset 0 -1px 0 rgba(255, 255, 255, 0.1),
    inset 0 0 20px rgba(255, 255, 255, 0.08),
    0 8px 32px rgba(0, 0, 0, 0.18);
}
/* Borde de luz */
.lg-glass::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 2;
  padding: 1px;
  border-radius: inherit;
  pointer-events: none;
  background: linear-gradient(135deg, rgba(255, 255, 255, 0.7), rgba(255, 255, 255, 0.05) 40%, rgba(255, 255, 255, 0.05) 60%, rgba(255, 255, 255, 0.4));
  mask: linear-gradient(#000 0 0) content-box exclude, linear-gradient(#000 0 0);
}
/* Reflejo que sigue al cursor (--x / --y los pone track()) */
.lg-glass::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  border-radius: inherit;
  pointer-events: none;
  opacity: var(--lg-hover, 0);
  transition: opacity 0.3s;
  background: radial-gradient(circle 140px at var(--x, 50%) var(--y, 0%), rgba(255, 255, 255, var(--lg-shine, 0.25)), transparent 70%);
}
.lg-glass:hover {
  --lg-hover: 1;
}
.lg-text {
  color: #fff;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.18);
}
.lg-light .lg-text {
  color: #1d1d1f;
  text-shadow: none;
}
@keyframes lg-drift {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33% { transform: translate(8%, -6%) scale(1.12); }
  66% { transform: translate(-6%, 7%) scale(0.94); }
}
`;

// Guarda la posición del cursor para el reflejo de .lg-glass::after
function track(e: MouseEvent<HTMLElement>) {
  const r = e.currentTarget.getBoundingClientRect();
  e.currentTarget.style.setProperty("--x", `${e.clientX - r.left}px`);
  e.currentTarget.style.setProperty("--y", `${e.clientY - r.top}px`);
}

interface StageProps {
  bg: Wallpaper;
  blur: number;
  opacity: number;
  shine: number;
  className?: string;
  children: ReactNode;
}

// Fondo de degradado animado sobre el que se ve el cristal
function Stage({
  bg,
  blur,
  opacity,
  shine,
  className = "relative h-[560px] w-full",
  children,
}: StageProps) {
  const light = bg === "light";
  const wall = walls[bg] ?? walls.aurora;
  const vars = {
    "--lg-blur": `${blur}px`,
    "--lg-a": light ? Math.min(0.6, opacity / 100 + 0.23) : opacity / 100,
    "--lg-shine": shine / 100,
  } as CSSProperties;

  return (
    <div
      className={`lg-font overflow-hidden rounded-[22px] ${className} ${light ? "lg-light" : ""}`}
      style={vars}
    >
      <style>{glassCss}</style>
      <div className="absolute inset-0 overflow-hidden" style={{ background: wall.base }}>
        <div className="absolute inset-0" style={{ filter: "blur(60px)" }}>
          {wall.blobs.map((color, i) => (
            <div
              key={i}
              className="absolute h-[75%] w-[75%] rounded-full"
              style={{
                left: blobPositions[i]?.[0],
                top: blobPositions[i]?.[1],
                background: `radial-gradient(circle, ${color} 0%, transparent 68%)`,
                opacity: light ? 1 : 0.9,
                animation: `lg-drift 20s ease-in-out ${-i * 6}s infinite`,
              }}
            />
          ))}
        </div>
        <div
          className="absolute inset-0"
          style={{ backgroundImage: grain, opacity: 0.04, mixBlendMode: "overlay" }}
        />
      </div>
      <div className="relative grid h-full w-full grid-cols-[100%] place-items-center p-4">{children}</div>
    </div>
  );
}

const tabs = [
  { icon: Home, label: "Home" },
  { icon: Compass, label: "Explore" },
  { icon: Library, label: "Library" },
  { icon: Search, label: "Search" },
];

interface GlassTabBarProps {
  bg?: Wallpaper;
  blur?: number;
  opacity?: number;
  shine?: number;
}

export default function GlassTabBar({
  bg = "aurora",
  blur = 20,
  opacity = 12,
  shine = 25,
}: GlassTabBarProps) {
  const glass = { bg, blur, opacity, shine };
  const [active, setActive] = useState(0);

  return (
    <Stage {...glass}>
      <div className="absolute inset-x-0 bottom-6 flex justify-center">
        <div onMouseMove={track} className="lg-glass flex rounded-full p-1">
          {tabs.map(({ icon: Icon, label }, i) => (
            <motion.button
              key={label}
              type="button"
              aria-pressed={active === i}
              onClick={() => setActive(i)}
              whileTap={{ scale: 0.92 }}
              transition={spring}
              className="lg-text relative z-[3] flex h-[54px] w-[74px] flex-col items-center justify-center gap-0.5"
            >
              {active === i && (
                // La key cambia en cada pulsación para repetir el estirón de la píldora
                <motion.span
                  key={`pill-${active}`}
                  layoutId="lg-tab-pill"
                  className="absolute inset-0 rounded-full"
                  initial={{ scaleX: 1 }}
                  animate={{ scaleX: [1, 1.15, 1] }}
                  transition={{
                    layout: spring,
                    scaleX: { duration: 0.45, ease: [0.25, 0.1, 0.25, 1] },
                  }}
                  style={{
                    background: "rgba(255,255,255,.22)",
                    boxShadow: "inset 0 1px 0 rgba(255,255,255,.55), 0 2px 8px rgba(0,0,0,.08)",
                  }}
                />
              )}
              <Icon className="relative h-[22px] w-[22px]" strokeWidth={1.75} />
              <span className="relative text-[11px] font-medium">{label}</span>
            </motion.button>
          ))}
        </div>
      </div>
    </Stage>
  );
}
```

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