CSS Magnetic Mercury Ripple Button

The button leans toward your cursor like it is magnetised, a liquid mercury highlight tracks the pointer across its surface, and clicks send a ripple out from the exact point of contact. Fourteen lines of JavaScript write two custom properties — every visual is CSS.

Live DemoUpdated Aug 10, 2026

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The code

<div class="cb-15">
  <div class="cb-15__stage">
    <button class="cb-15__btn" type="button">
      <span class="cb-15__mercury" aria-hidden="true"></span>
      <span class="cb-15__ripple" aria-hidden="true"></span>
      <span class="cb-15__label">Explore the system</span>
    </button>
  </div>
</div>

<div class="cb-15">
  <div class="cb-15__stage">
    <button class="cb-15__btn" type="button">
      <span class="cb-15__mercury" aria-hidden="true"></span>
      <span class="cb-15__ripple" aria-hidden="true"></span>
      <span class="cb-15__label">Explore the system</span>
    </button>
  </div>
</div>

@import url('https://fonts.googleapis.com/css2?family=Sora:wght@400;500;600;700&display=swap');

.cb-15 {
  --bg: #08090c;
  --btn: #101319;
  --line: #262b36;
  --ink: #f2f5fa;
  --accent: #a3e635;
  --ripple: #a3e635;
  --pull: 13px;
  --radius: 1.15rem;
  --spring: linear(0,.35 6%,.78 14%,1.05 22%,1.09 27%,1.03 36%,1 50%,1);
  --sans: "Sora",ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif;
  width: 100%;
  min-height: 100vh;
  min-height: 100svh;
  display: block;
  background: radial-gradient(38rem 24rem at 50% 50%, color-mix(in oklab,var(--accent) 8%,transparent), transparent 70%), var(--bg);
  font-family: var(--sans);
  -webkit-font-smoothing: antialiased;
}

@supports (color: oklch(50% 0 0)) {
  .cb-15 {
    --accent: oklch(87% .19 124);
    --btn: oklch(20% .015 260);
    --line: oklch(31% .02 260);
  }
}

@media (prefers-color-scheme: light) {
  .cb-15:not([data-theme="dark"]) {
    --bg: #f2f3f5;
    --btn: #111318;
    --line: #2a2f3a;
  }
}

.cb-15[data-theme="light"] {
  --bg: #f2f3f5;
  --btn: #111318;
  --line: #2a2f3a;
}

.cb-15,
.cb-15 *,
.cb-15 *::before,
.cb-15 *::after {
  box-sizing: border-box;
}

.cb-15__stage {
  min-height: 100vh;
  min-height: 100svh;
  display: grid;
  place-items: center;
  padding: clamp(1.5rem,6vw,4rem);
}

.cb-15__btn {
  --mx: 50%;
  --my: 50%;
  --dx: 0;
  --dy: 0;
  position: relative;
  overflow: hidden;
  isolation: isolate;
  cursor: pointer;
  min-height: 3.75rem;
  padding: 0 2.2rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font: inherit;
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -.01em;
  color: var(--ink);
  background: linear-gradient(180deg,color-mix(in oklab,var(--btn) 82%,white 5%),var(--btn));
  box-shadow: 0 20px 44px -24px color-mix(in oklab,black 90%,transparent), inset 0 1px 0 color-mix(in oklab,white 12%,transparent);
  translate: calc(var(--dx) * var(--pull)) calc(var(--dy) * var(--pull) * .6);
  transition: translate .45s var(--spring), border-color .3s ease, box-shadow .3s ease;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
}

.cb-15__label {
  position: relative;
  z-index: 2;
  display: inline-block;
  transition: translate .5s var(--spring);
}

.cb-15__btn:hover .cb-15__label {
  translate: calc(var(--dx) * 4px) calc(var(--dy) * 3px);
}

.cb-15__mercury {
  position: absolute;
  inset: -1px;
  z-index: 1;
  border-radius: inherit;
  opacity: 0;
  background: radial-gradient(9rem 6rem at var(--mx) var(--my), color-mix(in oklab,var(--accent) 55%,transparent), transparent 62%), radial-gradient(3.2rem 3.2rem at var(--mx) var(--my), color-mix(in oklab,white 55%,transparent), transparent 70%);
  filter: blur(2px) saturate(1.2);
  transition: opacity .35s ease;
}

.cb-15__btn:hover {
  border-color: color-mix(in oklab,var(--accent) 45%,var(--line));
}

.cb-15__btn:hover .cb-15__mercury {
  opacity: .9;
}

.cb-15__btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 4px;
}

.cb-15__btn:active {
  scale: .985;
}

.cb-15__ripple {
  position: absolute;
  z-index: 1;
  top: var(--my);
  left: var(--mx);
  width: 1rem;
  height: 1rem;
  margin: -.5rem 0 0 -.5rem;
  border-radius: 50%;
  pointer-events: none;
  opacity: 0;
  background: radial-gradient(circle, color-mix(in oklab,var(--ripple) 70%,transparent), transparent 70%);
}

.cb-15__btn.is-rippling .cb-15__ripple {
  animation: cb-15-ripple .62s cubic-bezier(.16,1,.3,1) forwards;
}

@keyframes cb-15-ripple {
  0% {
    opacity: .85;
    scale: 0;
  }

  100% {
    opacity: 0;
    scale: 22;
  }
}

@media (prefers-reduced-motion: reduce) {
  .cb-15__btn {
    translate: 0 0 !important;
    transition: none;
  }

  .cb-15__label {
    transition: none;
    translate: 0 0 !important;
  }

  .cb-15__ripple {
    display: none;
  }
}

@media (forced-colors: active) {
  .cb-15__btn {
    background: ButtonFace;
    color: ButtonText;
    border: 1px solid ButtonText;
  }

  .cb-15__mercury,
    .cb-15__ripple {
    display: none;
  }
}

@import url('https://fonts.googleapis.com/css2?family=Sora:wght@400;500;600;700&display=swap');

.cb-15 {
  --bg: #08090c;
  --btn: #101319;
  --line: #262b36;
  --ink: #f2f5fa;
  --accent: #a3e635;
  --ripple: #a3e635;
  --pull: 13px;
  --radius: 1.15rem;
  --spring: linear(0,.35 6%,.78 14%,1.05 22%,1.09 27%,1.03 36%,1 50%,1);
  --sans: "Sora",ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif;
  width: 100%;
  min-height: 100vh;
  min-height: 100svh;
  display: block;
  background: radial-gradient(38rem 24rem at 50% 50%, color-mix(in oklab,var(--accent) 8%,transparent), transparent 70%), var(--bg);
  font-family: var(--sans);
  -webkit-font-smoothing: antialiased;
}

@supports (color: oklch(50% 0 0)) {
  .cb-15 {
    --accent: oklch(87% .19 124);
    --btn: oklch(20% .015 260);
    --line: oklch(31% .02 260);
  }
}

@media (prefers-color-scheme: light) {
  .cb-15:not([data-theme="dark"]) {
    --bg: #f2f3f5;
    --btn: #111318;
    --line: #2a2f3a;
  }
}

.cb-15[data-theme="light"] {
  --bg: #f2f3f5;
  --btn: #111318;
  --line: #2a2f3a;
}

.cb-15,
.cb-15 *,
.cb-15 *::before,
.cb-15 *::after {
  box-sizing: border-box;
}

.cb-15__stage {
  min-height: 100vh;
  min-height: 100svh;
  display: grid;
  place-items: center;
  padding: clamp(1.5rem,6vw,4rem);
}

.cb-15__btn {
  --mx: 50%;
  --my: 50%;
  --dx: 0;
  --dy: 0;
  position: relative;
  overflow: hidden;
  isolation: isolate;
  cursor: pointer;
  min-height: 3.75rem;
  padding: 0 2.2rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font: inherit;
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -.01em;
  color: var(--ink);
  background: linear-gradient(180deg,color-mix(in oklab,var(--btn) 82%,white 5%),var(--btn));
  box-shadow: 0 20px 44px -24px color-mix(in oklab,black 90%,transparent), inset 0 1px 0 color-mix(in oklab,white 12%,transparent);
  translate: calc(var(--dx) * var(--pull)) calc(var(--dy) * var(--pull) * .6);
  transition: translate .45s var(--spring), border-color .3s ease, box-shadow .3s ease;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
}

.cb-15__label {
  position: relative;
  z-index: 2;
  display: inline-block;
  transition: translate .5s var(--spring);
}

.cb-15__btn:hover .cb-15__label {
  translate: calc(var(--dx) * 4px) calc(var(--dy) * 3px);
}

.cb-15__mercury {
  position: absolute;
  inset: -1px;
  z-index: 1;
  border-radius: inherit;
  opacity: 0;
  background: radial-gradient(9rem 6rem at var(--mx) var(--my), color-mix(in oklab,var(--accent) 55%,transparent), transparent 62%), radial-gradient(3.2rem 3.2rem at var(--mx) var(--my), color-mix(in oklab,white 55%,transparent), transparent 70%);
  filter: blur(2px) saturate(1.2);
  transition: opacity .35s ease;
}

.cb-15__btn:hover {
  border-color: color-mix(in oklab,var(--accent) 45%,var(--line));
}

.cb-15__btn:hover .cb-15__mercury {
  opacity: .9;
}

.cb-15__btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 4px;
}

.cb-15__btn:active {
  scale: .985;
}

.cb-15__ripple {
  position: absolute;
  z-index: 1;
  top: var(--my);
  left: var(--mx);
  width: 1rem;
  height: 1rem;
  margin: -.5rem 0 0 -.5rem;
  border-radius: 50%;
  pointer-events: none;
  opacity: 0;
  background: radial-gradient(circle, color-mix(in oklab,var(--ripple) 70%,transparent), transparent 70%);
}

.cb-15__btn.is-rippling .cb-15__ripple {
  animation: cb-15-ripple .62s cubic-bezier(.16,1,.3,1) forwards;
}

@keyframes cb-15-ripple {
  0% {
    opacity: .85;
    scale: 0;
  }

  100% {
    opacity: 0;
    scale: 22;
  }
}

@media (prefers-reduced-motion: reduce) {
  .cb-15__btn {
    translate: 0 0 !important;
    transition: none;
  }

  .cb-15__label {
    transition: none;
    translate: 0 0 !important;
  }

  .cb-15__ripple {
    display: none;
  }
}

@media (forced-colors: active) {
  .cb-15__btn {
    background: ButtonFace;
    color: ButtonText;
    border: 1px solid ButtonText;
  }

  .cb-15__mercury,
    .cb-15__ripple {
    display: none;
  }
}

(() => {
  const btn = document.querySelector('.cb-15__btn');
  if (!btn) return;
  let box = null;
  btn.addEventListener('pointerenter', () => { box = btn.getBoundingClientRect(); });
  btn.addEventListener('pointermove', (e) => {
    if (e.pointerType !== 'mouse') return;
    box = box || btn.getBoundingClientRect();
    const nx = (e.clientX - box.left) / box.width;
    const ny = (e.clientY - box.top) / box.height;
    btn.style.setProperty('--mx', (nx * 100).toFixed(2) + '%');
    btn.style.setProperty('--my', (ny * 100).toFixed(2) + '%');
    btn.style.setProperty('--dx', (nx - 0.5).toFixed(3));
    btn.style.setProperty('--dy', (ny - 0.5).toFixed(3));
  });
  btn.addEventListener('pointerleave', () => {
    box = null;
    btn.style.setProperty('--dx', '0');
    btn.style.setProperty('--dy', '0');
  });
  btn.addEventListener('click', () => {
    btn.classList.remove('is-rippling');
    void btn.offsetWidth; // restart the keyframes
    btn.classList.add('is-rippling');
  });
})();

(() => {
  const btn = document.querySelector('.cb-15__btn');
  if (!btn) return;
  let box = null;
  btn.addEventListener('pointerenter', () => { box = btn.getBoundingClientRect(); });
  btn.addEventListener('pointermove', (e) => {
    if (e.pointerType !== 'mouse') return;
    box = box || btn.getBoundingClientRect();
    const nx = (e.clientX - box.left) / box.width;
    const ny = (e.clientY - box.top) / box.height;
    btn.style.setProperty('--mx', (nx * 100).toFixed(2) + '%');
    btn.style.setProperty('--my', (ny * 100).toFixed(2) + '%');
    btn.style.setProperty('--dx', (nx - 0.5).toFixed(3));
    btn.style.setProperty('--dy', (ny - 0.5).toFixed(3));
  });
  btn.addEventListener('pointerleave', () => {
    box = null;
    btn.style.setProperty('--dx', '0');
    btn.style.setProperty('--dy', '0');
  });
  btn.addEventListener('click', () => {
    btn.classList.remove('is-rippling');
    void btn.offsetWidth; // restart the keyframes
    btn.classList.add('is-rippling');
  });
})();

Here's a working CSS Button from CodeFronts. Use it as-is or adapt to your framework. All classes are scoped under a unique prefix so the code won't collide with your existing styles. MIT licensed.
Demo: CSS Magnetic Mercury Ripple Button
Source: https://codefronts.com/components/css-buttons/css-magnetic-mercury-ripple-button/

The button leans toward your cursor like it is magnetised, a liquid mercury highlight tracks the pointer across its surface, and clicks send a ripple out from the exact point of contact. Fourteen lines of JavaScript write two custom properties — every visual is CSS.
## HTML
```html
<div class="cb-15">
  <div class="cb-15__stage">
    <button class="cb-15__btn" type="button">
      <span class="cb-15__mercury" aria-hidden="true"></span>
      <span class="cb-15__ripple" aria-hidden="true"></span>
      <span class="cb-15__label">Explore the system</span>
    </button>
  </div>
</div>
```
## CSS
```css
@import url('https://fonts.googleapis.com/css2?family=Sora:wght@400;500;600;700&display=swap');

.cb-15 {
  --bg: #08090c;
  --btn: #101319;
  --line: #262b36;
  --ink: #f2f5fa;
  --accent: #a3e635;
  --ripple: #a3e635;
  --pull: 13px;
  --radius: 1.15rem;
  --spring: linear(0,.35 6%,.78 14%,1.05 22%,1.09 27%,1.03 36%,1 50%,1);
  --sans: "Sora",ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif;
  width: 100%;
  min-height: 100vh;
  min-height: 100svh;
  display: block;
  background: radial-gradient(38rem 24rem at 50% 50%, color-mix(in oklab,var(--accent) 8%,transparent), transparent 70%), var(--bg);
  font-family: var(--sans);
  -webkit-font-smoothing: antialiased;
}

@supports (color: oklch(50% 0 0)) {
  .cb-15 {
    --accent: oklch(87% .19 124);
    --btn: oklch(20% .015 260);
    --line: oklch(31% .02 260);
  }
}

@media (prefers-color-scheme: light) {
  .cb-15:not([data-theme="dark"]) {
    --bg: #f2f3f5;
    --btn: #111318;
    --line: #2a2f3a;
  }
}

.cb-15[data-theme="light"] {
  --bg: #f2f3f5;
  --btn: #111318;
  --line: #2a2f3a;
}

.cb-15,
.cb-15 *,
.cb-15 *::before,
.cb-15 *::after {
  box-sizing: border-box;
}

.cb-15__stage {
  min-height: 100vh;
  min-height: 100svh;
  display: grid;
  place-items: center;
  padding: clamp(1.5rem,6vw,4rem);
}

.cb-15__btn {
  --mx: 50%;
  --my: 50%;
  --dx: 0;
  --dy: 0;
  position: relative;
  overflow: hidden;
  isolation: isolate;
  cursor: pointer;
  min-height: 3.75rem;
  padding: 0 2.2rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font: inherit;
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -.01em;
  color: var(--ink);
  background: linear-gradient(180deg,color-mix(in oklab,var(--btn) 82%,white 5%),var(--btn));
  box-shadow: 0 20px 44px -24px color-mix(in oklab,black 90%,transparent), inset 0 1px 0 color-mix(in oklab,white 12%,transparent);
  translate: calc(var(--dx) * var(--pull)) calc(var(--dy) * var(--pull) * .6);
  transition: translate .45s var(--spring), border-color .3s ease, box-shadow .3s ease;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
}

.cb-15__label {
  position: relative;
  z-index: 2;
  display: inline-block;
  transition: translate .5s var(--spring);
}

.cb-15__btn:hover .cb-15__label {
  translate: calc(var(--dx) * 4px) calc(var(--dy) * 3px);
}

.cb-15__mercury {
  position: absolute;
  inset: -1px;
  z-index: 1;
  border-radius: inherit;
  opacity: 0;
  background: radial-gradient(9rem 6rem at var(--mx) var(--my), color-mix(in oklab,var(--accent) 55%,transparent), transparent 62%), radial-gradient(3.2rem 3.2rem at var(--mx) var(--my), color-mix(in oklab,white 55%,transparent), transparent 70%);
  filter: blur(2px) saturate(1.2);
  transition: opacity .35s ease;
}

.cb-15__btn:hover {
  border-color: color-mix(in oklab,var(--accent) 45%,var(--line));
}

.cb-15__btn:hover .cb-15__mercury {
  opacity: .9;
}

.cb-15__btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 4px;
}

.cb-15__btn:active {
  scale: .985;
}

.cb-15__ripple {
  position: absolute;
  z-index: 1;
  top: var(--my);
  left: var(--mx);
  width: 1rem;
  height: 1rem;
  margin: -.5rem 0 0 -.5rem;
  border-radius: 50%;
  pointer-events: none;
  opacity: 0;
  background: radial-gradient(circle, color-mix(in oklab,var(--ripple) 70%,transparent), transparent 70%);
}

.cb-15__btn.is-rippling .cb-15__ripple {
  animation: cb-15-ripple .62s cubic-bezier(.16,1,.3,1) forwards;
}

@keyframes cb-15-ripple {
  0% {
    opacity: .85;
    scale: 0;
  }

  100% {
    opacity: 0;
    scale: 22;
  }
}

@media (prefers-reduced-motion: reduce) {
  .cb-15__btn {
    translate: 0 0 !important;
    transition: none;
  }

  .cb-15__label {
    transition: none;
    translate: 0 0 !important;
  }

  .cb-15__ripple {
    display: none;
  }
}

@media (forced-colors: active) {
  .cb-15__btn {
    background: ButtonFace;
    color: ButtonText;
    border: 1px solid ButtonText;
  }

  .cb-15__mercury,
    .cb-15__ripple {
    display: none;
  }
}
```

## JavaScript
```js
(() => {
  const btn = document.querySelector('.cb-15__btn');
  if (!btn) return;
  let box = null;
  btn.addEventListener('pointerenter', () => { box = btn.getBoundingClientRect(); });
  btn.addEventListener('pointermove', (e) => {
    if (e.pointerType !== 'mouse') return;
    box = box || btn.getBoundingClientRect();
    const nx = (e.clientX - box.left) / box.width;
    const ny = (e.clientY - box.top) / box.height;
    btn.style.setProperty('--mx', (nx * 100).toFixed(2) + '%');
    btn.style.setProperty('--my', (ny * 100).toFixed(2) + '%');
    btn.style.setProperty('--dx', (nx - 0.5).toFixed(3));
    btn.style.setProperty('--dy', (ny - 0.5).toFixed(3));
  });
  btn.addEventListener('pointerleave', () => {
    box = null;
    btn.style.setProperty('--dx', '0');
    btn.style.setProperty('--dy', '0');
  });
  btn.addEventListener('click', () => {
    btn.classList.remove('is-rippling');
    void btn.offsetWidth; // restart the keyframes
    btn.classList.add('is-rippling');
  });
})();
```

Paste this into ChatGPT, Claude, Cursor, or any coding assistant. The block below is pre-framed with everything the AI needs to integrate this demo into your project — markup, styles, scoping notes, and the source URL. Hit Copy and paste straight into your chat.

Here's a working CSS Button from CodeFronts. Use it as-is or adapt to your framework. All classes are scoped under a unique prefix so the code won't collide with your existing styles. MIT licensed.
Demo: CSS Magnetic Mercury Ripple Button
Source: https://codefronts.com/components/css-buttons/css-magnetic-mercury-ripple-button/

The button leans toward your cursor like it is magnetised, a liquid mercury highlight tracks the pointer across its surface, and clicks send a ripple out from the exact point of contact. Fourteen lines of JavaScript write two custom properties — every visual is CSS.
## HTML
```html
<div class="cb-15">
  <div class="cb-15__stage">
    <button class="cb-15__btn" type="button">
      <span class="cb-15__mercury" aria-hidden="true"></span>
      <span class="cb-15__ripple" aria-hidden="true"></span>
      <span class="cb-15__label">Explore the system</span>
    </button>
  </div>
</div>
```
## CSS
```css
@import url('https://fonts.googleapis.com/css2?family=Sora:wght@400;500;600;700&display=swap');

.cb-15 {
  --bg: #08090c;
  --btn: #101319;
  --line: #262b36;
  --ink: #f2f5fa;
  --accent: #a3e635;
  --ripple: #a3e635;
  --pull: 13px;
  --radius: 1.15rem;
  --spring: linear(0,.35 6%,.78 14%,1.05 22%,1.09 27%,1.03 36%,1 50%,1);
  --sans: "Sora",ui-sans-serif,system-ui,-apple-system,"Segoe UI",sans-serif;
  width: 100%;
  min-height: 100vh;
  min-height: 100svh;
  display: block;
  background: radial-gradient(38rem 24rem at 50% 50%, color-mix(in oklab,var(--accent) 8%,transparent), transparent 70%), var(--bg);
  font-family: var(--sans);
  -webkit-font-smoothing: antialiased;
}

@supports (color: oklch(50% 0 0)) {
  .cb-15 {
    --accent: oklch(87% .19 124);
    --btn: oklch(20% .015 260);
    --line: oklch(31% .02 260);
  }
}

@media (prefers-color-scheme: light) {
  .cb-15:not([data-theme="dark"]) {
    --bg: #f2f3f5;
    --btn: #111318;
    --line: #2a2f3a;
  }
}

.cb-15[data-theme="light"] {
  --bg: #f2f3f5;
  --btn: #111318;
  --line: #2a2f3a;
}

.cb-15,
.cb-15 *,
.cb-15 *::before,
.cb-15 *::after {
  box-sizing: border-box;
}

.cb-15__stage {
  min-height: 100vh;
  min-height: 100svh;
  display: grid;
  place-items: center;
  padding: clamp(1.5rem,6vw,4rem);
}

.cb-15__btn {
  --mx: 50%;
  --my: 50%;
  --dx: 0;
  --dy: 0;
  position: relative;
  overflow: hidden;
  isolation: isolate;
  cursor: pointer;
  min-height: 3.75rem;
  padding: 0 2.2rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font: inherit;
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -.01em;
  color: var(--ink);
  background: linear-gradient(180deg,color-mix(in oklab,var(--btn) 82%,white 5%),var(--btn));
  box-shadow: 0 20px 44px -24px color-mix(in oklab,black 90%,transparent), inset 0 1px 0 color-mix(in oklab,white 12%,transparent);
  translate: calc(var(--dx) * var(--pull)) calc(var(--dy) * var(--pull) * .6);
  transition: translate .45s var(--spring), border-color .3s ease, box-shadow .3s ease;
  touch-action: manipulation;
  -webkit-tap-highlight-color: transparent;
}

.cb-15__label {
  position: relative;
  z-index: 2;
  display: inline-block;
  transition: translate .5s var(--spring);
}

.cb-15__btn:hover .cb-15__label {
  translate: calc(var(--dx) * 4px) calc(var(--dy) * 3px);
}

.cb-15__mercury {
  position: absolute;
  inset: -1px;
  z-index: 1;
  border-radius: inherit;
  opacity: 0;
  background: radial-gradient(9rem 6rem at var(--mx) var(--my), color-mix(in oklab,var(--accent) 55%,transparent), transparent 62%), radial-gradient(3.2rem 3.2rem at var(--mx) var(--my), color-mix(in oklab,white 55%,transparent), transparent 70%);
  filter: blur(2px) saturate(1.2);
  transition: opacity .35s ease;
}

.cb-15__btn:hover {
  border-color: color-mix(in oklab,var(--accent) 45%,var(--line));
}

.cb-15__btn:hover .cb-15__mercury {
  opacity: .9;
}

.cb-15__btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 4px;
}

.cb-15__btn:active {
  scale: .985;
}

.cb-15__ripple {
  position: absolute;
  z-index: 1;
  top: var(--my);
  left: var(--mx);
  width: 1rem;
  height: 1rem;
  margin: -.5rem 0 0 -.5rem;
  border-radius: 50%;
  pointer-events: none;
  opacity: 0;
  background: radial-gradient(circle, color-mix(in oklab,var(--ripple) 70%,transparent), transparent 70%);
}

.cb-15__btn.is-rippling .cb-15__ripple {
  animation: cb-15-ripple .62s cubic-bezier(.16,1,.3,1) forwards;
}

@keyframes cb-15-ripple {
  0% {
    opacity: .85;
    scale: 0;
  }

  100% {
    opacity: 0;
    scale: 22;
  }
}

@media (prefers-reduced-motion: reduce) {
  .cb-15__btn {
    translate: 0 0 !important;
    transition: none;
  }

  .cb-15__label {
    transition: none;
    translate: 0 0 !important;
  }

  .cb-15__ripple {
    display: none;
  }
}

@media (forced-colors: active) {
  .cb-15__btn {
    background: ButtonFace;
    color: ButtonText;
    border: 1px solid ButtonText;
  }

  .cb-15__mercury,
    .cb-15__ripple {
    display: none;
  }
}
```

## JavaScript
```js
(() => {
  const btn = document.querySelector('.cb-15__btn');
  if (!btn) return;
  let box = null;
  btn.addEventListener('pointerenter', () => { box = btn.getBoundingClientRect(); });
  btn.addEventListener('pointermove', (e) => {
    if (e.pointerType !== 'mouse') return;
    box = box || btn.getBoundingClientRect();
    const nx = (e.clientX - box.left) / box.width;
    const ny = (e.clientY - box.top) / box.height;
    btn.style.setProperty('--mx', (nx * 100).toFixed(2) + '%');
    btn.style.setProperty('--my', (ny * 100).toFixed(2) + '%');
    btn.style.setProperty('--dx', (nx - 0.5).toFixed(3));
    btn.style.setProperty('--dy', (ny - 0.5).toFixed(3));
  });
  btn.addEventListener('pointerleave', () => {
    box = null;
    btn.style.setProperty('--dx', '0');
    btn.style.setProperty('--dy', '0');
  });
  btn.addEventListener('click', () => {
    btn.classList.remove('is-rippling');
    void btn.offsetWidth; // restart the keyframes
    btn.classList.add('is-rippling');
  });
})();
```

How this works

All the JS does is publish normalised pointer coordinates; CSS decides what they mean, so the same two variables drive the magnet, the highlight and the ripple origin:

btn.addEventListener('pointermove', (e) => {
  const r = btn.getBoundingClientRect();
  btn.style.setProperty('--mx', ((e.clientX - r.left) / r.width * 100) + '%');
  btn.style.setProperty('--my', ((e.clientY - r.top) / r.height * 100) + '%');
  btn.style.setProperty('--dx', ((e.clientX - r.left) / r.width - .5).toFixed(3));
  btn.style.setProperty('--dy', ((e.clientY - r.top) / r.height - .5).toFixed(3));
});

The magnet is a translate driven by --dx/--dy with a hard cap, so the button can never wander far from its layout position:

.cb-15__btn{ translate:calc(var(--dx) * var(--pull)) calc(var(--dy) * var(--pull) * .6); }

The mercury is a radial gradient positioned at var(--mx) var(--my); the ripple is a single span scaled from 0 with its own centre at the same point, re-triggered by removing and re-adding the class after a forced reflow. On pointerleave the variables reset to 0/50% and the spring easing carries the button home.

Make it yours

--pull is the magnet strength in px; 10-14px feels premium, above 24px feels broken.
Kill the magnet on touch by only binding pointermove when e.pointerType === 'mouse' — the highlight still works on tap.
Change the mercury to a spotlight by swapping the radial gradient's colour for white at low alpha.
Ripple colour and speed live in --ripple and the animation duration; 620ms matches Material's timing.
Combine with any other demo — the pointer variables are independent of the button's skin.

Gotchas — read before shipping

Never read layout inside pointermove without care: getBoundingClientRect() per move is acceptable for one element, but cache it on pointerenter if you have a grid of them.
A magnetic button must not move under a keyboard user — the effect is bound to pointer events only, and :focus-visible gets a static ring instead.
Ripples that start at the centre on keyboard activation look broken; default --mx/--my to 50% so Enter/Space produce a symmetric ripple.
prefers-reduced-motion must disable the magnet and the ripple; vestibular triggers include small unexpected translations.
Set touch-action:manipulation or the 300ms tap delay on mobile makes the ripple feel laggy.

Browser support

Chrome	Safari	Firefox	Edge
111+	16.2+	113+	111+

Floor set by oklch(), color-mix() as this demo is written. The core technique itself goes back further — Chrome 104+.

Pointer Events are universal; individual transform properties need Chrome 104 / Safari 14.1 / Firefox 72. color-mix() (Chrome 111 / Safari 16.2 / Firefox 113) degrades to the flat hex tokens declared first.

Techniques used in this demo

filterMDN ↗radial-gradient()MDN ↗color-mix()MDN ↗@keyframesMDN ↗clamp()MDN ↗place-items / place-contentMDN ↗