Staggered entrance

<!doctype html><html lang="ja"><meta charset="utf-8"><meta name="viewport" content="width=device-width,initial-scale=1"><style>body{margin:0;min-height:300px}.sample{width:100%;height:100%;min-height:190px;position:relative;box-sizing:border-box;display:grid;place-items:center;overflow:hidden;padding:18px;background:#f4f3ee;color:#242424;font-family:Arial,Meiryo,sans-serif}.sample *{box-sizing:border-box}.sample button{font:600 11px Arial,Meiryo,sans-serif;border:1px solid #333;border-radius:999px;min-height:36px;padding:8px 14px;background:#fff;color:#222;cursor:pointer;touch-action:manipulation}.sample :focus-visible{outline:2px solid #555;outline-offset:4px}.sample small{font-size:10px;color:#666;line-height:1.5}.sample .adv-wrap{width:min(100%,260px);display:flex;flex-direction:column;align-items:center;gap:10px}.sample .adv-status{min-height:13px;text-align:center;font-size:10px;color:#666}.sample svg{max-width:100%}@media(prefers-reduced-motion:reduce){.sample *{transition:none!important;animation:none!important}}.sample .stagger-letters{display:flex;gap:3px;align-items:center;justify-content:center;height:100px;width:100%}.sample .stagger-letters i{font:900 55px Arial;letter-spacing:-.08em;font-style:normal;display:block}</style><div class="sample"><div class="adv-wrap"><div class="stagger-letters" aria-label="good"><i>g</i><i>o</i><i>o</i><i>d</i><i>.</i></div><button type="button" class="stagger-play">順番に登場させる ↗</button></div></div><script>const lifecycle=function lifecycle(root,options={}){const abort=new AbortController(),animations=new Set(),cleanup=[],pause=[];const os=globalThis.matchMedia?.('(prefers-reduced-motion:reduce)').matches||false;let reduced=options.reducedMotion??os,live=true;return{get reduced(){return reduced},get live(){return live},on(node,event,fn,opts={}){node.addEventListener(event,fn,{...opts,signal:abort.signal})},track(a){animations.add(a);a.finished.then(()=>animations.delete(a),()=>animations.delete(a));return a},stop(){animations.forEach(a=>a.cancel());animations.clear()},cleanup(fn){cleanup.push(fn)},onPause(fn){pause.push(fn)},destroy(){if(!live)return;live=false;abort.abort();this.stop();cleanup.forEach(fn=>fn())},setAuto(value){reduced=!value||os;if(reduced){this.stop();pause.forEach(fn=>fn())}}}};const control=(function stagger(root,options){const c=lifecycle(root,options),letters=[...root.querySelectorAll('.stagger-letters i')],button=root.querySelector('.stagger-play');c.on(button,'click',()=>{c.stop();if(c.reduced)return;letters.forEach((n,i)=>c.track(n.animate([{transform:'translateY(28px) rotate(10deg)',opacity:0},{transform:'translateY(0) rotate(0)',opacity:1}],{duration:540,delay:i*100,fill:'backwards',easing:'cubic-bezier(.16,1,.3,1)'})))});return c})(document,{reducedMotion:matchMedia('(prefers-reduced-motion:reduce)').matches});addEventListener('pagehide',()=>control.destroy(),{once:true});</script></html>