# Odometer roll Subtle web animation sketch from [https://mighil.com/animations](https://mighil.com/animations). - **Live demo:** https://mighil.com/animations/odometer-roll - **Standalone HTML:** https://mighil.com/animations/odometer-roll?download=1 - **This file:** https://mighil.com/animations/odometer-roll/odometer-roll.md - **Technique:** `digits` ## What it does Columns roll to the new digits on the same ease. ## Instructions for AI / coding agents Implement this micro-interaction in the user's stack (vanilla HTML, React, Vue, Svelte, etc.). 1. Use the **HTML** as the DOM structure (adapt JSX/templates as needed; keep class names and ids). 2. Include the **Theme** CSS (or map the same variables into the host design system). It switches light/dark with `prefers-color-scheme`. 3. Apply the **CSS** as-is when possible. It uses `var(--text-color)`, `var(--heading-color)`, `var(--background-color)`, etc. from the theme so both modes work. 4. Run the **JavaScript** after the markup mounts. Prefer `DOMContentLoaded` or a framework `useEffect` / `onMount`. 5. Keep motion respectful of `prefers-reduced-motion` if the snippet already checks it. 6. Do not depend on mighil.com runtime or fonts. Theme variables are enough for color. 7. If porting to a component, expose the interactive root via a ref and preserve accessibility attributes (`aria-*`, `role`, `button` types). ## Theme (auto light / dark) ```css /* Auto light / dark — follows prefers-color-scheme */ :root{ color-scheme: light dark; --text-color: hsl(0, 0%, 18%); --heading-color: hsl(0, 0%, 18%); --background-color: hsl(0, 0%, 99%); --bg-color: hsl(0, 0%, 99%); --link-color: hsl(0, 0%, 18%); --visited-color: hsl(0, 0%, 18%); --blockquote-color: hsl(0, 0%, 18%); --code-bg-color: hsl(0, 0%, 95%); --code-color: hsl(0, 0%, 18%); --sub-color: hsl(0, 0%, 29%); } @media (prefers-color-scheme: dark){ :root{ --text-color: hsl(35, 25%, 85%); --heading-color: hsl(35.2, 32.6%, 82.5%); --background-color: hsl(60, 2.2%, 8.8%); --bg-color: hsl(60, 2.2%, 8.8%); --link-color: hsl(34.7, 55.3%, 79.8%); --visited-color: hsla(34.7, 55.3%, 79.8%, 0.85); --blockquote-color: hsl(35, 30%, 75%); --code-bg-color: hsl(30, 5%, 7.8%); --code-color: limegreen; --sub-color: hsla(34.7, 24.7%, 84.9%, 0.78); } } ``` ## HTML ```html
0123456789 0123456789 0123456789
``` ## CSS ```css .odo{display:inline-flex;gap:4px;font-variant-numeric:tabular-nums} .odo-digit{ position:relative;width:1.35em;height:1.5em;overflow:hidden;border-radius:6px; border:1px solid color-mix(in srgb,var(--text-color) 12%,transparent); background:color-mix(in srgb,var(--text-color) 3%,transparent); font-size:1.35rem;font-weight:600;text-align:center; } .odo-digit > b{ display:block;font-weight:600;will-change:transform; } .odo-digit i{ display:flex;align-items:center;justify-content:center; height:1.5em;font-style:normal;font-weight:600; } @media (prefers-reduced-motion: reduce){ .grow-link::after,.wipe,.wipe .b,.shuffle .card,.odo-digit > b,.flap-reel,.step-node,.step-line > i, .switch,.switch::after,.copy-btn .c-idle,.copy-btn .c-done,.field label,.tip-bubble,.chip,.like-btn svg, .disc-btn svg,.disc-panel,.snack,.save-btn,.ux-box,.seg-pill,.soft-tabs-ink,.list-actions,.success-banner,.search-clear,.pin-btn svg,.submit-ring rect, .hold-btn .hold-fill,.toast,.menu-btn .menu-line,.stars button,.conn,.retry-btn,.sort-item,.mute-btn .wave,.mute-btn .x-line,.wizard-dots span,.cart-badge,.range-bubble, .filter-list li,.upload-bar > i,.quota-track > i,.quota-tip,.splitbtn-toggle svg,.splitbtn-menu,.presence-dot, .draft-banner,.tag-chip,.empty-state,.empty-item,.deadline,.deadline-clock,.deadline-track > i,.edge-fade-mask,.dirty-bar,.seen-ticks path,.nudge-field,.stack-card, .blur-line,.xface span,.magnet-chip,.confirm-btn,.confirm-btn span,.offline-banner,.sort-flip-btn svg,.sort-flip-list li,.react-fan,.react-fan button,.sticky-cta, .pw-toggle .pw-eye,.pw-toggle .pw-slash,.otp input,.exp-search,.exp-search input,.ok-field input,.ok-field .ok-check,.unread-dot,.unread-check,.unread-row,.sync-label,.sync-btn .sync-arrows,.sync-btn .sync-check, .inline-edit .ie-title,.inline-edit .ie-rename,.inline-edit .ie-panel,.inline-edit .ie-input,.inline-edit .ie-bar, .ghost-wrap .ghost-hint,.ghost-wrap .ghost-key,.cmd-palette,.cmd-palette li,.cmd-stage::before,.crumb-mid,.crumb-more,.diff-add,.diff-add > .diff-add-inner,.slot > i,.zoom-thumb,.zoom-full,.zoom-caption, .bulk-bar,.bulk-check svg,.bulk-row,.env-switch .env-ink,.env-switch button,.invite-btn .invite-idle,.invite-btn .invite-done,.flag-row,.flag-sw,.flag-sw::after,.deploy-node,.deploy-node i,.deploy-wire > b,.ws-ink,.ws-item .ws-check,.thread,.thread-body,.thread-resolve svg, .unfurl-card,.unfurl-thumb,.seat,.form-prog-bar > i,.form-prog-field,.form-prog-field svg,.mention b,.glyph-tile path,.glyph-tile line,.glyph-tile circle{transition:none!important} } ``` ## JavaScript ```js // Odometer — forward reel with coast + soft lock const odo = document.getElementById('odo'); const ODO_H = 1.5; // em — match .odo-digit i height function ensureOdoStrip(el) { if (!el || el.dataset.stripReady === '1') return; const glyphs = [...el.querySelectorAll('i')].map((n) => n.textContent); // three cycles so we can always roll forward a full turn + land if (glyphs.length === 10) { for (let pass = 0; pass < 2; pass++) { glyphs.forEach((g) => { const i = document.createElement('i'); i.textContent = g; el.appendChild(i); }); } } el.dataset.stripReady = '1'; el._odoPos = Number(el.dataset.n || 0); } function odoCommit(el, pos) { el.getAnimations().forEach((a) => a.cancel()); el.style.transition = 'none'; el.style.transform = 'translateY(-' + (pos * ODO_H) + 'em)'; el._odoPos = pos; } function runOdo() { if (!odo) return; const digits = [...odo.querySelectorAll('.odo-digit > b')]; const target = String(Math.floor(100 + Math.random() * 899)); digits.forEach((el, i) => { ensureOdoStrip(el); const n = Number(target[i] || 0); let prev = el._odoPos == null ? Number(el.dataset.n || 0) : el._odoPos; if (prev >= 10) { prev = prev % 10; odoCommit(el, prev); void el.offsetWidth; } const next = prev + 10 + ((n - (prev % 10) + 10) % 10); el.dataset.n = String(n); const delay = reduce ? 0 : (digits.length - 1 - i) * 90; clearTimeout(el._odoTimer); el._odoTimer = setTimeout(() => { if (reduce) { odoCommit(el, n); return; } const startY = prev * ODO_H; const endY = next * ODO_H; const dist = next - prev; // Keep speed through the roll; only ease the last half-digit const coastY = endY - 0.45 * ODO_H; el.getAnimations().forEach((a) => a.cancel()); el.style.transition = 'none'; el.style.transform = 'translateY(-' + startY + 'em)'; const anim = el.animate( [ { transform: 'translateY(-' + startY + 'em)' }, { transform: 'translateY(-' + coastY + 'em)', offset: 0.9, easing: 'cubic-bezier(.3,.05,.6,.4)' }, { transform: 'translateY(-' + endY + 'em)', easing: 'cubic-bezier(.2,.85,.25,1)' } ], { duration: 900 + dist * 40, easing: 'linear', fill: 'forwards' } ); el._odoPos = next; const token = (el._odoToken = (el._odoToken || 0) + 1); anim.finished .then(() => { if (el._odoToken !== token) return; if (typeof anim.commitStyles === 'function') anim.commitStyles(); else el.style.transform = 'translateY(-' + endY + 'em)'; anim.cancel(); }) .catch(() => {}); }, delay); }); } if (odo) { const start = String(Math.floor(100 + Math.random() * 899)); odo.querySelectorAll('.odo-digit > b').forEach((el, i) => { ensureOdoStrip(el); const n = Number(start[i] || 0); odoCommit(el, n); el.dataset.n = String(n); void el.offsetWidth; }); } document.querySelectorAll('[data-act]').forEach((btn) => { btn.addEventListener('click', (e) => { e.stopPropagation(); const act = btn.getAttribute('data-act'); if (act === 'odo') runOdo(); }); }); ``` --- _Source: https://mighil.com/animations/odometer-roll_