:root{
  --bg:#0a0d14;
  --panel:rgba(255,255,255,.045);
  --panel-2:rgba(255,255,255,.075);
  --line:rgba(178,196,224,.15);
  --line-2:rgba(178,196,224,.32);
  --text:#eef1f7;
  --text-2:#aab4c4;
  --text-3:#737d8d;
  --text-4:#4c5565;
  --accent:#7fa8d9;
  --warm:#d9a054;
  --bad:#e0665a;
  --sans:'Inter',-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;
  --serif:'Instrument Serif',Georgia,'Times New Roman',serif;
  --mono:'IBM Plex Mono',ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
}
*{margin:0;padding:0;box-sizing:border-box}
[hidden]{display:none !important}
body.boot *{transition:none !important; animation:none !important}
html,body{height:100%}
body{
  background:var(--bg); color:var(--text); font-family:var(--sans);
  -webkit-font-smoothing:antialiased;
  background-image:radial-gradient(130% 95% at 50% -8%, #141a26 0%, #0d1118 52%, #070910 100%);
  background-attachment:fixed;
}
:focus-visible{outline:2px solid var(--accent); outline-offset:2px; border-radius:6px}
button{font-family:inherit; color:inherit; background:none; border:none}

.page{display:flex; flex-direction:column; min-height:100vh}

/* ---------- top bar ---------- */
.bar{
  display:flex; justify-content:space-between; align-items:center; gap:12px;
  padding:max(14px, env(safe-area-inset-top)) 20px 0; flex:none;
}
.home,.icon{
  display:inline-flex; align-items:center; gap:7px; height:38px;
  color:var(--text); text-decoration:none; font:500 14px/1 var(--sans);
  background:var(--panel); border:1px solid var(--line); border-radius:999px;
  cursor:pointer; transition:background .15s, border-color .15s;
}
.home{padding:0 14px 0 10px}
.home span{font-family:var(--serif); font-size:18px; letter-spacing:.01em}
.icon{width:38px; justify-content:center; padding:0}
.home:hover,.icon:hover{background:var(--panel-2); border-color:var(--line-2)}

/* ---------- layout ---------- */
main{
  flex:1; display:grid; grid-template-columns:minmax(0,1fr) 322px;
  gap:24px; padding:10px 20px max(22px, env(safe-area-inset-bottom));
  align-items:start; align-content:start;
  width:100%; max-width:1128px; margin:0 auto;
}
.stage{display:flex; flex-direction:column; gap:12px; min-width:0}
.titleblock{max-width:680px; padding:6px 2px 2px}
.kicker{font-size:11.5px; font-weight:600; letter-spacing:.15em; text-transform:uppercase; color:var(--text-3)}
h1{
  font-family:var(--serif); font-weight:400; font-size:clamp(34px, 4.4vw, 58px);
  line-height:.98; letter-spacing:-.01em; margin:4px 0 8px;
}
.sub{font-size:14.5px; line-height:1.55; color:var(--text-2); max-width:66ch}
.sub em{color:var(--text); font-style:italic; font-family:var(--serif); font-size:17.5px}
.sub b{font-weight:600; color:var(--text)}
.lbl{
  font-size:11px; font-weight:600; letter-spacing:.12em; text-transform:uppercase;
  color:var(--text-3); display:flex; justify-content:space-between; align-items:baseline; gap:8px;
}
.lbl .hint{
  font:600 11px/1 var(--mono); letter-spacing:.02em; text-transform:none; color:var(--accent);
}
.srlive{position:absolute; width:1px; height:1px; overflow:hidden; clip:rect(0 0 0 0); white-space:nowrap}
.code{font:600 12px/1.3 var(--mono); letter-spacing:.02em; color:var(--accent); text-transform:none}

/* ---------- the scene ---------- */
.slate{
  position:relative; width:100%; overflow:hidden; border-radius:14px;
  background:#05070d; border:1px solid rgba(160,186,224,.13);
  box-shadow:0 22px 46px -30px #000, 0 1px 0 rgba(200,220,255,.06) inset;
  isolation:isolate;
}
#scene{display:block; width:100%; aspect-ratio:1.5; height:auto; cursor:grab; touch-action:none}
#scene.dragging{cursor:grabbing}
.hud{
  position:absolute; left:0; top:0; right:0; pointer-events:none;
  display:flex; align-items:flex-start; justify-content:space-between; gap:10px;
  padding:9px 12px; font:600 11.5px/1.4 var(--mono); letter-spacing:.03em;
  color:rgba(238,244,252,.8); text-shadow:0 1px 6px rgba(0,0,0,.9);
}
.hud .rt{text-align:right; color:rgba(238,244,252,.56)}
.chip{
  display:inline-flex; align-items:center; gap:6px; padding:4px 10px 4px 8px;
  border-radius:999px; background:rgba(127,168,217,.18); color:#cfe2ff;
  text-transform:none; letter-spacing:.01em; text-shadow:none;
}
.chip::before{content:''; width:7px; height:7px; border-radius:50%; background:#7fd99c; box-shadow:0 0 8px #7fd99c}
.chip.lo{background:rgba(217,160,84,.2); color:#ffd9a0}
.chip.lo::before{background:var(--warm); box-shadow:0 0 8px var(--warm)}
.chip.hi{background:rgba(224,102,90,.22); color:#ffc4bd}
.chip.hi::before{background:var(--bad); box-shadow:0 0 8px var(--bad); animation:blink 1s steps(2) infinite}
.chip.off{background:rgba(170,180,196,.14); color:#c7cfdb}
.chip.off::before{background:var(--text-3); box-shadow:none}
@keyframes blink{50%{opacity:.25}}

.tracewrap{
  width:100%; border-radius:12px; background:rgba(255,255,255,.028);
  border:1px solid var(--line); overflow:hidden;
}
#trace{display:block; width:100%; height:108px}

.cap{display:flex; gap:7px 18px; flex-wrap:wrap; padding:1px 2px}
.legend{
  display:inline-flex; align-items:center; gap:6px;
  font:500 11px/1.3 var(--sans); color:var(--text-3);
}
.sw{width:13px; height:13px; border-radius:4px; display:inline-block; flex:none}
.sw.s-ok{background:rgba(127,168,217,.3); border:1.5px solid var(--accent)}
.sw.s-lo{background:rgba(217,160,84,.22); border:1.5px dashed var(--warm)}
.sw.s-hi{background:rgba(224,102,90,.24); border:1.5px dashed var(--bad)}

/* ---------- panel ---------- */
.panel{
  display:flex; flex-direction:column; gap:14px; position:sticky; top:12px;
  background:var(--panel); border:1px solid var(--line); border-radius:16px;
  padding:14px 15px 13px;
}
.grp{display:flex; flex-direction:column; gap:8px}
.row{display:flex; gap:6px}
.note{font-size:11.5px; line-height:1.5; color:var(--text-3)}
.note b{color:var(--text-2); font-weight:600}

input[type=range]{
  -webkit-appearance:none; appearance:none; width:100%; height:26px;
  background:transparent; cursor:pointer; display:block;
}
input[type=range]::-webkit-slider-runnable-track{
  height:5px; border-radius:99px; background:rgba(255,255,255,.13);
}
input[type=range]::-moz-range-track{height:5px; border-radius:99px; background:rgba(255,255,255,.13)}
input[type=range]::-webkit-slider-thumb{
  -webkit-appearance:none; appearance:none; width:19px; height:19px; margin-top:-7px;
  border-radius:50%; background:var(--accent); border:none;
  box-shadow:0 1px 5px rgba(0,0,0,.5), 0 0 0 1px rgba(0,0,0,.25);
}
input[type=range]::-moz-range-thumb{
  width:19px; height:19px; border-radius:50%; background:var(--accent); border:none;
  box-shadow:0 1px 5px rgba(0,0,0,.5);
}
#drv::-webkit-slider-thumb{background:var(--warm)}
#drv::-moz-range-thumb{background:var(--warm)}

.readout{
  border-radius:11px; padding:10px 12px; border:1px solid var(--line);
  background:var(--panel-2); font-size:12.5px; line-height:1.5; color:var(--text-2);
}
.readout .big{
  display:block; font:400 25px/1.1 var(--serif); color:var(--text); margin-bottom:4px;
  letter-spacing:.01em;
}
.readout .big b{color:var(--accent); font-weight:400}
.readout .dim{color:var(--text-3); font-size:12px}
.readout.alt{background:none; border-color:var(--line); font-size:11.5px}
.readout.alt dl{display:grid; grid-template-columns:auto 1fr; gap:4px 10px; align-items:baseline}
.readout.alt dt{color:var(--text-3)}
.readout.alt dd{font:600 12px/1.3 var(--mono); color:var(--text); text-align:right}
.readout.alt dd span{color:var(--text-3); font-weight:400}
.readout.alt .hi{color:var(--accent)}
.readout.alt .lo{color:var(--warm)}
.readout.alt .bad{color:var(--bad)}

.seg{display:flex; gap:5px}
.seg button{
  flex:1; height:32px; border-radius:9px; cursor:pointer; padding:0 2px;
  background:var(--panel-2); border:1px solid var(--line);
  font:600 12px/1 var(--sans); color:var(--text-2);
  transition:background .14s, border-color .14s, color .14s;
}
.seg.sm button{font-size:11px; height:30px; border-radius:8px}
.seg button:hover{border-color:var(--line-2); color:var(--text)}
.seg button.is-on{background:var(--accent); border-color:var(--accent); color:#06162e}

.btn{
  display:flex; align-items:center; justify-content:center; text-align:center; gap:8px;
  padding:0 10px; height:34px; border-radius:10px; cursor:pointer; width:100%;
  background:var(--panel-2); border:1px solid var(--line);
  font:600 12px/1 var(--sans); color:var(--text-2);
  transition:background .14s, border-color .14s, transform .08s, color .14s;
}
.btn:hover{background:rgba(255,255,255,.12); border-color:var(--line-2); color:var(--text)}
.btn:active{transform:translateY(1px)}
.btn.big{height:42px; font-size:13.5px; color:var(--text)}
.btn.big[aria-pressed=true]{
  background:rgba(127,168,217,.15); border-color:rgba(127,168,217,.5); color:#cfe2ff;
}
.btn.wide[aria-pressed=false]{color:var(--text-3)}

.foot{
  font-size:11.5px; line-height:1.6; color:#5d6676;
  border-top:1px solid var(--line); padding-top:12px;
}
.link{
  color:var(--accent); cursor:pointer; font:inherit; font-weight:600; text-align:left;
  text-decoration:underline; text-underline-offset:2px;
}
.link:hover{color:#b3d2ff}

/* ---------- about ---------- */
dialog{
  border:none; padding:0; background:transparent; max-width:min(706px, 92vw);
  max-height:86vh; margin:auto;
}
dialog::backdrop{background:rgba(4,6,11,.68); backdrop-filter:blur(3px)}
.about{
  position:relative; background:#11151f; border:1px solid rgba(178,196,224,.2);
  border-radius:18px; padding:26px 28px 24px; overflow-y:auto; max-height:86vh;
  box-shadow:0 30px 60px -28px #000;
}
.about h2{
  font-family:var(--serif); font-weight:400; font-size:31px; line-height:1.05;
  margin:4px 0 14px; color:var(--text);
}
.about h3{
  font-family:var(--serif); font-weight:400; font-size:22px; line-height:1.1;
  margin:22px 0 10px; color:var(--text);
}
.about p{font-size:14.5px; line-height:1.68; color:var(--text-2); margin-bottom:12px}
.about p b{color:var(--text); font-weight:600}
.about em,.about i{font-style:italic}
.about .fine{
  font-size:12.5px; color:var(--text-3); border-top:1px solid var(--line);
  padding-top:12px; margin-top:16px; margin-bottom:0;
}
.about .code{font-size:12px; color:var(--accent)}
.x{
  position:absolute; top:14px; right:14px; width:32px; height:32px; cursor:pointer;
  display:flex; align-items:center; justify-content:center; color:var(--text-3);
  background:var(--panel-2); border:1px solid var(--line); border-radius:999px;
}
.x:hover{color:var(--text); border-color:var(--line-2)}

/* ---------- narrow ---------- */
@media (max-width:920px){
  main{grid-template-columns:minmax(0,1fr); gap:16px; padding:8px 14px max(20px, env(safe-area-inset-bottom))}
  .panel{position:static}
  h1{font-size:clamp(30px, 8.6vw, 42px)}
  .sub{font-size:14px}
  #scene{aspect-ratio:1.28}
  #trace{height:96px}
  .about{padding:22px 20px 20px; border-radius:15px}
  .about h2{font-size:26px}
  .about h3{font-size:20px}
}
@media (max-width:420px){
  .hud{font-size:10.5px; padding:8px 10px}
  .readout .big{font-size:23px}
  .seg.sm button{font-size:10.5px}
}