Cache hit and miss

<div class="demo"><div class="head"><strong>CACHE</strong><span id="outcome">HIT</span></div><div class="scene"><div class="chip" id="client">browser</div><span class="arrow">→</span><div class="chip" id="cache">cache</div><span class="arrow">→</span><div class="chip" id="origin">origin</div></div><div class="foot"><span id="route">browser → cache → browser</span><span>tap to switch</span></div></div>

.demo{width:min(92vw,660px);height:min(86vh,310px);border:1px solid var(--line);border-radius:14px;background:var(--surface);padding:clamp(10px,2.5vmin,20px);display:flex;flex-direction:column;gap:clamp(6px,1.7vmin,12px);box-shadow:0 10px 35px rgba(0,0,0,.07);font:500 clamp(10px,2.8vmin,15px)/1.35 ui-monospace,SFMono-Regular,Consolas,monospace}
.head,.foot{display:flex;align-items:center;justify-content:space-between;gap:8px}.head strong{color:var(--accent);font-size:1.05em}.foot{color:var(--muted);font-size:.85em;min-height:1.4em}.scene{flex:1;min-height:0;position:relative;display:flex;align-items:center;justify-content:center;gap:clamp(5px,1.5vmin,12px)}.chip{border:1px solid var(--line);background:var(--bg);border-radius:7px;padding:.4em .6em;text-align:center}.on{border-color:var(--accent)!important;background:color-mix(in srgb,var(--accent) 12%,var(--surface))!important;color:var(--accent)!important}.dim{opacity:.42}.arrow{color:var(--muted)}
.scene .chip{min-width:20%;height:50%;display:grid;place-items:center}.scene .arrow{font-size:1.5em}

let miss=false;function advance(){miss=!miss;document.getElementById("outcome").textContent=miss?"MISS · fill cache":"HIT · return";document.getElementById("origin").classList.toggle("on",miss);document.getElementById("origin").classList.toggle("dim",!miss);document.getElementById("cache").classList.add("on");document.getElementById("route").textContent=miss?"browser → cache → origin → cache":"browser → cache → browser"}advance();const timer=setInterval(advance,1300);document.querySelector(".demo").addEventListener("pointerdown",()=>{clearInterval(timer);advance()})