Swift default actor isolation

<div class="v"><header><b>ACTOR ISOLATION</b><span id="state"></span></header><main><div class="lanes"><div class="lane" id="mainlane"></div><div class="lane" id="otherlane"></div></div></main><footer>state belongs to one isolation domain</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,3.2vmin,17px)/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:.28} .lanes{height:100%;display:flex;flex-direction:column;justify-content:center;gap:9px}.lane{height:36%;border:1px solid var(--line);border-radius:6px;display:flex;align-items:center;justify-content:space-around;font:600 .8em ui-monospace,monospace}.lane b{padding:6px;border-radius:4px}.lane.warning{border-color:var(--accent-2)}

let n=0;function draw(){document.getElementById("mainlane").innerHTML="<b>MAIN ACTOR</b><b class=active>UI state</b>";document.getElementById("otherlane").innerHTML=n?"<b>BACKGROUND</b><b>crossing requires hop</b>":"<b>BACKGROUND</b><b>independent work</b>";document.getElementById("otherlane").classList.toggle("warning",!!n);document.getElementById("state").textContent=n?"isolated access":"safe lane";n=1-n}draw();setInterval(draw,1300)