:root{
  --bg:#e9eaee; --card:#fff; --ink:#0b0b0d; --muted:#6b6e78; --line:#ededf1;
  --blue:#2f5bea; --red:#c8261f; --chip:#f0f1f4; --track:#dcdde3;
}
*{box-sizing:border-box}
html,body{height:100%}
body{margin:0;background:var(--bg);color:var(--ink);
  font-family:-apple-system,BlinkMacSystemFont,"SF Pro Text","Inter","Segoe UI",system-ui,sans-serif;
  -webkit-font-smoothing:antialiased;overflow:hidden}
.app{display:grid;grid-template-columns:360px 1fr;gap:18px;padding:12px;height:100vh}
.panel{background:var(--card);border-radius:28px;padding:26px 24px 20px;overflow-y:auto;
  box-shadow:0 8px 30px rgba(20,20,40,.08)}
.stage{background:#f1f2f6;border-radius:28px;position:relative;overflow:hidden;
  box-shadow:0 8px 30px rgba(20,20,40,.08)}
#view{position:absolute;inset:0;width:100%;height:100%;display:block}
h1{margin:0;font-size:23px;font-weight:800;letter-spacing:-.02em;line-height:1.15}
h1 span{color:var(--blue)}
.sub{margin:5px 0 0;font-size:12px;color:var(--muted);font-weight:600}
section{border-top:1px solid var(--line);margin-top:16px;padding-top:14px}
.sec{font-size:13px;color:var(--muted);font-weight:600;margin-bottom:10px}
.btn{display:flex;align-items:center;justify-content:center;gap:6px;width:100%;border:0;cursor:pointer;
  border-radius:999px;font:inherit;font-size:14px;font-weight:700;padding:13px 16px;transition:transform .08s,opacity .15s}
.btn:active{transform:scale(.98)}
.btn:disabled{opacity:.5;cursor:default}
.btn.dark{background:#000;color:#fff}
.btn.soft{background:var(--chip);color:#222;margin-top:10px}
.btn.blue{background:var(--blue);color:#fff;width:auto;padding:12px 18px;white-space:nowrap}
.btn.mini{background:transparent;color:var(--muted);width:auto;padding:4px 0;font-size:13px;font-weight:600;
  justify-content:flex-start;text-decoration:underline;text-underline-offset:2px;margin-top:8px}
.btn.mini:hover{color:var(--ink)}
.row{display:flex;justify-content:space-between;align-items:baseline;font-size:13px;font-weight:700;margin-top:12px}
.row label{color:#444}
.row output{color:var(--muted);font-variant-numeric:tabular-nums}
.row output.blue{color:var(--blue)} .row output.red{color:var(--red)}
.row.first{margin-top:0}
input[type=range]{-webkit-appearance:none;appearance:none;width:100%;height:20px;background:transparent;margin:2px 0 0;cursor:pointer}
input[type=range]::-webkit-slider-runnable-track{height:3px;background:var(--track);border-radius:2px}
input[type=range]::-webkit-slider-thumb{-webkit-appearance:none;width:15px;height:15px;border-radius:50%;background:#000;border:0;margin-top:-6px}
input[type=range]::-moz-range-track{height:3px;background:var(--track);border-radius:2px}
input[type=range]::-moz-range-thumb{width:15px;height:15px;border-radius:50%;background:#000;border:0}
.mode{display:flex;gap:10px;align-items:stretch}
select,textarea,input[type=password]{font:inherit;font-size:14px;font-weight:700;color:var(--ink);background:#fff;
  border:1px solid #e1e2e8;border-radius:14px;padding:11px 12px;width:100%;outline:none}
select{-webkit-appearance:none;appearance:none;flex:1;min-width:0;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='10' height='6'%3E%3Cpath d='M1 1l4 4 4-4' fill='none' stroke='%23333' stroke-width='1.5'/%3E%3C/svg%3E");
  background-repeat:no-repeat;background-position:right 12px center;padding-right:30px}
select:focus,textarea:focus,input[type=password]:focus{border-color:var(--blue)}
textarea{resize:vertical;min-height:64px;font-weight:500;margin-top:10px}
.status{font-size:12px;color:var(--muted);font-style:italic;margin:8px 0 0;min-height:14px;line-height:1.4}
.status.err{color:var(--red)}
details{margin-top:8px;font-size:13px;color:var(--muted)}
details summary{cursor:pointer;font-weight:600}
details .in{margin-top:8px;display:grid;gap:8px}
details small{font-size:12px;line-height:1.4}
.chk{display:flex;justify-content:space-between;align-items:center;font-size:14px;font-weight:700;padding:5px 0;cursor:pointer}
.chk input{-webkit-appearance:none;appearance:none;width:19px;height:19px;border:1.5px solid #cfd0d6;border-radius:6px;
  background:#fff;margin:0;cursor:pointer;display:grid;place-items:center}
.chk input:checked{background:#000;border-color:#000}
.chk input:checked::after{content:"";width:9px;height:5px;border-left:2px solid #fff;border-bottom:2px solid #fff;transform:rotate(-45deg) translate(1px,-1px)}
.exp{display:flex;gap:10px}
.hint{margin-top:16px;background:#f6f6f8;border-radius:14px;padding:12px 14px;font-size:12px;line-height:1.5;color:var(--muted);font-style:italic}
.empty{position:absolute;inset:0;display:grid;place-content:center;justify-items:center;gap:14px;text-align:center;
  color:var(--muted);font-size:13px;font-weight:600;padding:24px}
.empty.hide{display:none}
.empty .btn{width:auto;padding:11px 20px}
.stage.drag{outline:3px dashed var(--blue);outline-offset:-12px}
.hidden{display:none!important}
.dim{font-size:12px;color:var(--muted);font-weight:600;margin:8px 0 0;font-variant-numeric:tabular-nums}
.row.off{opacity:.4}
input[type=range]:disabled{opacity:.4;cursor:default}
.two{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:10px}
.two select{width:100%}
@media(max-width:860px){
  body{overflow:auto;height:auto}
  .app{grid-template-columns:1fr;height:auto}
  .stage{height:75vh;order:-1}
  .panel{overflow:visible}
}

.w100{width:100%}.mt8{margin-top:8px}
.back{display:inline-block;margin-bottom:12px;font-size:13px;font-weight:600;color:var(--muted);text-decoration:none}
.back:hover{color:var(--ink);text-decoration:underline}