Endowment effect

<div class="owned"><div class="product">FIELD KIT<div class="mark">F</div></div><div class="axis"><span>BEFORE</span><div class="track"><i id="marker"></i></div><span>IN USE</span></div><div class="value">VALUE MARKER <b id="val">$40</b></div></div>

@media(min-width:700px){body>div{transform:scale(1.45)}}.owned{display:flex;align-items:center;gap:clamp(12px,5vmin,42px);width:min(90%,590px);font:800 clamp(10px,max(1.8vmin,1vw),14px)/1.2 sans-serif}.product{width:clamp(84px,26vmin,200px);height:clamp(84px,26vmin,200px);background:var(--accent-2);color:#211b19;border:2px solid #211b19;box-shadow:6px 6px 0 var(--accent);padding:clamp(7px,2vmin,16px);flex:none;letter-spacing:.07em}.mark{font:900 clamp(34px,11vmin,90px)/1 sans-serif;text-align:center}.axis{flex:1;min-width:0;display:flex;flex-direction:column;gap:clamp(8px,2vmin,14px)}.axis span:last-child{text-align:right}.track{height:5px;background:var(--line);position:relative}.track i{position:absolute;top:-8px;left:0;width:20px;height:20px;border-radius:50%;background:var(--accent);transition:left .6s}.track i.right{left:calc(100% - 20px)}.value{position:absolute;bottom:clamp(7px,3vmin,22px);right:clamp(12px,5vmin,46px);color:var(--muted)}.value b{color:var(--accent)}

const marker=document.querySelector('#marker');const value=document.querySelector('#val');let own=false;function update(){marker.classList.toggle('right',own);value.textContent=own?'$65':'$40'}update();setInterval(()=>{own=!own;update()},1500);