Bloom filter

<div class="v"><header><b>BLOOM FILTER</b><span id="state"></span></header><main><div class="bits" id="bits"></div><div class="query" id="query"></div></main><footer>zero bit proves absence</footer></div>

.v{width:min(92vw,660px);height:min(86vh,310px);box-sizing:border-box;padding:clamp(9px,2.5vmin,18px);border:1px solid var(--line);border-radius:14px;background:var(--surface);display:flex;flex-direction:column;gap:7px;color:var(--fg);font:500 clamp(15px,4.5vmin,19px)/1.25 var(--font-sans, sans-serif)}.v header,.v footer{display:flex;justify-content:space-between;align-items:center;gap:8px;white-space:nowrap}.v header b{color:var(--accent);font-size:.9em}.v header span,.v footer{color:var(--muted);font-size:.82em}.v main{flex:1;min-height:0;position:relative;overflow:hidden}.v .mono{font-family:ui-monospace,SFMono-Regular,Consolas,monospace}.v .active{background:var(--accent)!important;color:var(--bg)!important;border-color:var(--accent)!important}.v .muted{opacity:.45} .bits{height:57%;display:flex;align-items:center;justify-content:center;gap:3px}.bit{width:25px;height:30px;border:1px solid var(--line);border-radius:4px;display:grid;place-items:center;font:700 .8em ui-monospace,monospace}.query{text-align:center;color:var(--accent);font:600 .85em ui-monospace,monospace}

let n=0;const base=[1,0,1,1,0,1,0,1];function draw(){const checks=n%2?[1,4,6]:[0,3,7];document.getElementById("bits").innerHTML=base.map((v,i)=>"<div class=\"bit "+(checks.includes(i)?"active":"")+"\">"+v+"</div>").join("");document.getElementById("query").textContent=n%2?"B: bit 1 = 0 → absent":"A: all bits = 1 → maybe";document.getElementById("state").textContent=n%2?"definitely absent":"possibly present";n++}draw();setInterval(draw,1300)