Builds the 240ms a click takes to feel right. Frontend at Mitra. Demos below are live, single-file, run on this page.
Cursor radius pulls the button along its axis. Spring-eased return when you leave the field.
// translate by (cursor − center) * 0.35 const r = btn.getBoundingClientRect(); const dx = (e.clientX − r.left − r.width/2) * 0.35; const dy = (e.clientY − r.top − r.height/2) * 0.35; btn.style.transform = `translate(${dx}px, ${dy}px)`;
transition: 600ms cubic-bezier(0.22, 0.8, 0.24, 1) · pull-radius: 180px · strength: 0.35
rotateX/rotateY from cursor offset. Children get translateZ for parallax. Spotlight follows the pointer.
// max ±12deg, clamped & damped const px = (e.clientX − r.left) / r.width − 0.5; const py = (e.clientY − r.top) / r.height − 0.5; card.style.transform = `rotateY(${px * 12}deg) rotateX(${−py * 12}deg)`; card.style.setProperty('--mx', `${px*100+50}%`);
perspective: 900px · max-tilt: 12deg · transition: 240ms cubic-bezier(0.22, 0.8, 0.24, 1)
Three counters animate together when this section enters viewport. Side-by-side proves easing isn't decoration — it's tone of voice.
// IntersectionObserver fires once const animate = (el, ease) => { const t0 = performance.now(); const step = (t) => { const p = Math.min(1, (t−t0)/1400); el.textContent = Math.floor( ease(p) * 1247 ).toLocaleString(); if (p < 1) requestAnimationFrame(step); }; requestAnimationFrame(step); };
duration: 1400ms · target: 1247 · 60fps via requestAnimationFrame
FLIP (First, Last, Invert, Play). Measure source rect, position destination, invert with transform, play forward. No layout thrash.
// FLIP — first, last, invert, play const first = src.getBoundingClientRect(); moveToDestination(src); const last = src.getBoundingClientRect(); const dx = first.left − last.left; const dy = first.top − last.top; src.animate( [{transform:`translate(${dx}px,${dy}px)`}, {transform:'none'}], {duration:420, easing:'var(--ease)'} );
duration: 420ms cubic-bezier(0.22, 0.8, 0.24, 1) · backdrop blur 12px · ESC to close
Sticky element that responds to its own scroll container's offset. Threshold-based, hardware-accelerated.
Most micro-interactions are paid for in milliseconds the user can feel. The right ones are paid for in trust.
I build for the second category. A magnetic button isn't a flourish — it's a signal that the system is paying attention to where you are.
Scroll further. The header shrinks. The logo trims. The background blurs. None of it is decorative — it gives back the screen real estate the page needs.
Every animation in this lab respects prefers-reduced-motion. The settings panel forces it manually for users who want to try both modes.
Bottom of the scroller. Header is fully compact now. Threshold was 40px.
// state changes once per threshold cross scroller.addEventListener('scroll', () => { const compact = scroller.scrollTop > 40; header.classList.toggle( 'compact', compact ); });
threshold: 40px · transition: 240ms cubic-bezier(0.22, 0.8, 0.24, 1) · backdrop-filter blur 8px