Client-side rendering

<section class="stage"><div class="heading">CSR <span class="hint">empty shell → script → UI</span></div><div class="csr-grid"><div class="tile shell">HTML<div class="blank">empty</div></div><div class="arrow">→</div><div class="tile bundle">JS<div class="bars"><i></i><i></i><i></i></div></div><div class="arrow">→</div><div class="tile result">VIEW<div class="mock"><i></i><i></i></div></div></div><div class="caption">The view waits for the script to execute</div></section>

.stage{width:min(94vw,780px);height:min(88vh,322px);padding:clamp(12px,3vmin,20px);border:1px solid var(--line);border-radius:16px;background:var(--surface);box-shadow:0 12px 36px #0001;display:flex;flex-direction:column;gap:clamp(7px,2vmin,14px);font:500 clamp(12px,3.5vmin,17px)/1.3 var(--font-sans,system-ui,sans-serif);overflow:hidden}.heading{display:flex;justify-content:space-between;align-items:center;gap:8px;font-weight:750;color:var(--accent)}.hint{color:var(--muted);font-size:clamp(12px,3.2vmin,14px);font-weight:500}.caption{margin-top:auto;color:var(--muted);font-size:clamp(12px,3.2vmin,14px)}.row{display:flex;gap:clamp(5px,1.5vmin,12px);align-items:center}.tile{padding:clamp(6px,1.8vmin,13px);border:1px solid var(--line);border-radius:9px;background:var(--bg);text-align:center;min-width:0}.arrow{color:var(--accent);font-weight:800}.stage [data-on]{transition:background .3s,border-color .3s,opacity .3s,transform .3s}.stage .on{border-color:var(--accent);background:color-mix(in srgb,var(--accent) 14%,var(--surface));color:var(--accent)}.csr-grid{display:flex;align-items:center;justify-content:center;gap:clamp(3px,1.3vmin,12px);flex:1}.csr-grid .tile{flex:1;max-width:150px;height:70%;display:flex;flex-direction:column;justify-content:space-between;font-weight:700}.blank{border:1px dashed var(--line);border-radius:6px;color:var(--muted);padding:10px 2px;font-weight:400}.bars,.mock{display:flex;flex-direction:column;gap:5px}.bars i,.mock i{height:8px;border-radius:5px;background:var(--line)}.bars i:nth-child(2),.mock i:nth-child(2){width:65%}.bundle,.result{opacity:.35;transition:opacity .3s}.stage[data-step="1"] .bundle,.stage[data-step="2"] .bundle,.stage[data-step="2"] .result{opacity:1}.stage[data-step="1"] .bars i,.stage[data-step="2"] .bars i{background:var(--accent-3)}.stage[data-step="2"] .mock i{background:var(--accent)}.stage small,.stage button,.stage .cards b,.stage .phase b,.stage .pair b,.stage .tree-mini b{font-size:clamp(12px,3.2vmin,14px)!important}

const stage=document.querySelector(".stage");let step=0;function tick(){stage.dataset.step=String(step);step=(step+1)%3}tick();let timer=setInterval(tick,950);stage.addEventListener("pointerdown",()=>{clearInterval(timer);tick()})