*{box-sizing:border-box}
:root{--bg:#0a0c10;--panel:#121722;--line:#293244;--txt:#f8fafc;--muted:#93a0b2;--accent:#7dd3fc}
html,body{margin:0;min-height:100%;font-family:Inter,system-ui,Arial,sans-serif;background:var(--bg);color:var(--txt)}
body{min-height:100vh}
.app{display:grid;grid-template-columns:330px 1fr;gap:18px;padding:18px;min-height:100vh}
.panel{background:var(--panel);border:1px solid var(--line);border-radius:18px;padding:18px;height:max-content;position:sticky;top:18px}
h1{font-size:21px;margin:0}h1 span{font-size:11px;color:var(--accent);vertical-align:top}
.sub{font-size:12px;color:var(--muted);line-height:1.5;margin:8px 0 18px}
.upload{display:flex;flex-direction:column;gap:5px;border:1px dashed #42516b;border-radius:13px;padding:16px;text-align:center;cursor:pointer;background:#0d121b}
.upload span{font-size:11px;color:var(--muted)}.upload input{display:none}
.group{margin-top:18px}.group>label{display:flex;justify-content:space-between;font-size:12px;font-weight:800;margin-bottom:8px}
.group small{display:block;font-size:10px;color:var(--muted);margin-top:6px}
.grid{display:grid;grid-template-columns:1fr 1fr;gap:7px}
.mat-btn,button,select{border:1px solid var(--line);background:#1a2230;color:var(--txt);border-radius:9px;padding:10px;font-weight:700}
.mat-btn{font-size:11px;cursor:pointer}.mat-btn.active{outline:2px solid var(--accent);background:#162838}
select,input[type=range]{width:100%}
select{padding:10px}
input[type=range]{accent-color:var(--accent)}
.check{display:flex;gap:8px;align-items:center;font-size:12px;margin:18px 0}
#demoBtn{width:100%;cursor:pointer}
.viewer{min-width:0;display:flex;flex-direction:column;gap:10px}
.toolbar{height:48px;display:flex;align-items:center;justify-content:space-between;background:var(--panel);border:1px solid var(--line);border-radius:14px;padding:0 14px;font-weight:800}
.pill{font-size:10px;padding:5px 8px;border-radius:999px;background:#1e293b;color:#bae6fd}
.stage{position:relative;overflow:hidden;min-height:680px;height:calc(100vh - 76px);border:1px solid var(--line);border-radius:18px;display:flex;align-items:center;justify-content:center;background:#20252e}
.checker{position:absolute;inset:0;background-color:#171b22;background-image:linear-gradient(45deg,#202630 25%,transparent 25%),linear-gradient(-45deg,#202630 25%,transparent 25%),linear-gradient(45deg,transparent 75%,#202630 75%),linear-gradient(-45deg,transparent 75%,#202630 75%);background-size:32px 32px;background-position:0 0,0 16px,16px -16px,-16px 0}
#glCanvas{width:min(75vw,760px);height:min(75vw,760px);max-width:88%;max-height:88%;position:relative;z-index:2;filter:drop-shadow(0 18px 35px rgba(0,0,0,.5))}
.hint{position:absolute;z-index:3;bottom:16px;left:50%;transform:translateX(-50%);font-size:11px;color:#cad5e1;background:rgba(0,0,0,.45);padding:7px 10px;border-radius:999px;pointer-events:none}
@media(max-width:900px){.app{grid-template-columns:1fr}.panel{position:static}.stage{min-height:480px;height:62vh}}