:root{
  --bg:#140f0a;
  --panel:rgba(255,255,255,.045);
  --panel-2:rgba(255,255,255,.075);
  --line:rgba(224,186,130,.16);
  --line-2:rgba(224,186,130,.32);
  --text:#f5efe4;
  --text-2:#cdbb9d;
  --text-3:#8f7c63;
  --text-4:#5f5140;
  --accent:#e0a23f;
  --accent-dim:#8a5a1d;
  --bit0:#4fc9bb;
  --bit1:#e0a23f;
  --good:#5fdb9f;
  --bad:#ff6d54;
  --slate:#170f09;
  --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%, #2a1f12 0%, #180f08 52%, #0d0804 100%);
  background-attachment:fixed;
}
:focus-visible{outline:2px solid var(--accent); outline-offset:2px; border-radius:6px}
button,input,textarea{font-family:inherit; color:inherit}
button{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) 330px;
  gap:26px; padding:10px 20px max(22px, env(safe-area-inset-bottom));
  align-items:start; align-content:start;
  width:100%; max-width:1104px; margin:0 auto;
}
.stage{display:flex; flex-direction:column; gap:15px; min-width:0}
.titleblock{max-width:660px; padding:6px 2px 0}
.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(32px, 4.2vw, 54px);
  line-height:.99; letter-spacing:-.01em; margin:4px 0 8px;
}
.sub{font-size:14.5px; line-height:1.55; color:var(--text-2); max-width:66ch}
.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-size:10px; font-weight:500; letter-spacing:.05em; text-transform:none; color:var(--text-4)}
.srlive{position:absolute; width:1px; height:1px; overflow:hidden; clip:rect(0 0 0 0); white-space:nowrap}
.code{font:600 12px/1 var(--mono); letter-spacing:.06em; color:var(--accent); text-transform:none}

/* ---------- text input ---------- */
.inputwrap{display:flex; flex-direction:column; gap:7px}
textarea{
  width:100%; resize:none; padding:11px 13px; border-radius:12px;
  border:1px solid var(--line); background:var(--panel-2);
  font:500 15px/1.4 var(--sans); color:var(--text);
}
textarea:focus{background:#1d140b; border-color:var(--line-2)}
.chips{display:flex; flex-wrap:wrap; gap:6px}
.chips button{
  height:28px; padding:0 11px; border-radius:999px; cursor:pointer;
  border:1px solid var(--line); background:var(--panel-2);
  color:var(--text-2); font:500 12px/1 var(--sans);
  transition:background .14s, border-color .14s, color .14s;
}
.chips button:hover{background:var(--panel); border-color:var(--line-2); color:var(--text)}
.chips button.is-on{background:var(--accent); border-color:var(--accent); color:#241803}

/* ---------- tree stage ---------- */
.slate{
  background:var(--slate); border-radius:18px; border:1px solid rgba(224,186,130,.1);
  padding:14px 14px 13px; min-width:0;
  box-shadow:0 1px 0 rgba(224,186,130,.06) inset, 0 20px 40px -26px #000;
  background-image:radial-gradient(115% 130% at 18% 0%, #22180d 0%, #170f09 66%);
}
.treescroll{overflow-x:auto; overflow-y:hidden; padding:4px 0 2px; -webkit-overflow-scrolling:touch}
.treescroll.overflowing{
  -webkit-mask-image:linear-gradient(90deg, #000 calc(100% - 28px), transparent 100%);
  mask-image:linear-gradient(90deg, #000 calc(100% - 28px), transparent 100%);
}
#tree{display:block; height:auto}

.node{transition:opacity .3s ease}
.node.pending{opacity:0}
.edge{transition:opacity .3s ease}
.edge.pending{opacity:0}
.node.dim,.edge.dim{opacity:.22}
.leaftile{fill:#0f2b26; stroke:rgba(79,201,187,.4); stroke-width:1.3}
.leaftile.hl{stroke:var(--bit0); stroke-width:2}
.leafglyph{font:600 15px var(--mono); fill:var(--text); text-anchor:middle; dominant-baseline:central}
.leafcount{font:500 10px var(--sans); fill:var(--text-3); text-anchor:middle}
.leafcode{font:600 9.5px var(--mono); fill:var(--accent); text-anchor:middle; letter-spacing:.03em}
.inode circle{fill:#2a1a08; stroke:rgba(224,162,63,.45); stroke-width:1.3}
.inode.hl circle{stroke:var(--accent); stroke-width:2}
.inode text{font:600 12px var(--mono); fill:var(--text-2); text-anchor:middle; dominant-baseline:central}
.edgeline{stroke:rgba(224,186,130,.22); stroke-width:1.6; transition:stroke .2s, stroke-width .2s}
.edgeline.hl0{stroke:var(--bit0); stroke-width:2.4}
.edgeline.hl1{stroke:var(--bit1); stroke-width:2.4}
.edgebit{font:700 9.5px var(--mono); text-anchor:middle; dominant-baseline:central}
.edgebit.bit0{fill:var(--bit0)}
.edgebit.bit1{fill:var(--bit1)}
.edgebitbg{fill:var(--slate)}

/* ---------- build controls ---------- */
.build{display:flex; align-items:center; gap:8px; padding-top:12px; border-top:1px solid rgba(224,186,130,.1); margin-top:10px}
.sq{
  width:30px; height:30px; display:flex; align-items:center; justify-content:center; flex:none;
  border-radius:9px; cursor:pointer; border:1px solid var(--line); background:var(--panel-2);
  color:var(--text-2); transition:background .14s, border-color .14s, color .14s;
}
.sq:hover{background:var(--panel); border-color:var(--line-2); color:var(--text)}
.sq.play{color:var(--accent)}
.sq:disabled{opacity:.35; cursor:default}
#scrub{flex:1}
.step{flex:none; font:500 11.5px/1 var(--mono); color:var(--text-3); min-width:9ch; text-align:right}

.legend{display:flex; gap:12px; flex-wrap:wrap; padding-top:10px}
.legend span{
  display:inline-flex; align-items:center; gap:5px; white-space:nowrap;
  font:500 10.5px/1 var(--sans); letter-spacing:.03em; color:var(--text-4);
}
.sw{width:11px; height:11px; border-radius:3px; display:inline-block; flex:none}
.sw.s-leaf{background:#0f2b26; border:1px solid rgba(79,201,187,.55)}
.sw.s-node{background:#2a1a08; border:1px solid rgba(224,162,63,.55); border-radius:50%}
.sw.s-bit0{background:var(--bit0); border-radius:50%}
.sw.s-bit1{background:var(--bit1); border-radius:50%}

input[type=range]{
  -webkit-appearance:none; appearance:none; width:100%; height:24px;
  background:transparent; cursor:pointer; display:block;
}
input[type=range]::-webkit-slider-runnable-track{height:5px; border-radius:99px; background:rgba(255,255,255,.1)}
input[type=range]::-moz-range-track{height:5px; border-radius:99px; background:rgba(255,255,255,.1)}
input[type=range]::-webkit-slider-thumb{
  -webkit-appearance:none; appearance:none; width:17px; height:17px; margin-top:-6px;
  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:17px; height:17px; border-radius:50%; background:var(--accent); border:none}

/* ---------- 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:15px 15px 13px;
}
.grp{display:flex; flex-direction:column; gap:8px}
.note{font-size:11.5px; line-height:1.5; color:var(--text-3)}
.note b{color:var(--text-2); font-weight:600}
.row{display:flex; gap:6px}

/* ---------- frequency table ---------- */
.freq{width:100%; border-collapse:collapse; max-height:260px; display:block; overflow-y:auto}
.freq thead,.freq tbody{display:block}
.freq tr{display:flex; align-items:center; gap:6px}
.freq thead tr{padding:0 2px 5px}
.freq th{
  flex:1; text-align:left; font:600 10px/1 var(--sans); letter-spacing:.08em;
  text-transform:uppercase; color:var(--text-4);
}
.freq th:first-child{flex:0 0 34px}
.freq th:nth-child(3){flex:0 0 56px}
.freq th:last-child{flex:0 0 32px; text-align:right}
.freq tbody tr{
  padding:5px 4px; border-radius:8px; cursor:default;
  transition:background .14s;
}
.freq tbody tr:hover,.freq tbody tr.hl{background:rgba(224,186,130,.12)}
.freq td{flex:1; font-size:12.5px; color:var(--text-2); display:flex; align-items:center}
.freq td:first-child{flex:0 0 34px; font:600 14px/1 var(--mono); color:var(--text)}
.freq td.glyph .sp{color:var(--text-4); font-size:11px}
.freq td:nth-child(2){color:var(--text-3); font:500 12px var(--mono)}
.freq td:nth-child(3){flex:0 0 56px; font:600 12px var(--mono); color:var(--accent); letter-spacing:.04em}
.freq td:last-child{flex:0 0 32px; justify-content:flex-end; font:500 11.5px var(--mono); color:var(--text-3)}

/* ---------- bars ---------- */
.bars{display:flex; flex-direction:column; gap:7px}
.barrow{display:flex; align-items:center; gap:8px}
.barname{flex:0 0 72px; font:500 11px/1 var(--sans); color:var(--text-3)}
.bartrack{flex:1; height:16px; border-radius:5px; background:rgba(255,255,255,.05); position:relative; overflow:hidden}
.barfill{height:100%; border-radius:5px; background:var(--text-4)}
.barrow.hu .barfill{background:var(--accent)}
.barfloor{position:absolute; top:-3px; bottom:-3px; width:2px; background:var(--good); opacity:.85}
.barval{flex:0 0 58px; text-align:right; font:600 11.5px/1 var(--mono); color:var(--text-2)}

.btn{
  display:flex; align-items:center; justify-content:center; gap:6px; text-align:center;
  padding:0 11px; height:36px; border-radius:10px; cursor:pointer; flex:1;
  background:var(--panel-2); border:1px solid var(--line);
  font:600 12.5px/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.wide{flex:1}

.foot{
  font-size:11.5px; line-height:1.6; color:var(--text-4);
  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:#f0bd6c}

/* ---------- about ---------- */
dialog{
  border:none; padding:0; background:transparent; max-width:min(700px, 92vw);
  max-height:86vh; margin:auto;
}
dialog::backdrop{background:rgba(10,6,2,.66); backdrop-filter:blur(3px)}
.about{
  position:relative; background:#19120a; border:1px solid rgba(224,186,130,.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 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 sup,.about sub{font-size:.7em}
.about .b0{color:var(--bit0); font-weight:700; font-family:var(--mono)}
.about .b1{color:var(--bit1); font-weight:700; font-family:var(--mono)}
.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)}
kbd{
  font:600 11px/1.6 var(--mono); background:rgba(255,255,255,.07);
  border:1px solid var(--line-2); border-bottom-width:2px; border-radius:5px; padding:1px 5px;
}
.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}
  .titleblock{padding-top:2px}
  h1{font-size:clamp(28px, 8.4vw, 40px)}
  .sub{font-size:14px}
  .slate{padding:11px 10px 11px; border-radius:15px}
  .freq{max-height:220px}
  .about{padding:22px 20px 20px; border-radius:15px}
  .about h2{font-size:26px}
}

@media (prefers-reduced-motion:reduce){
  *{transition-duration:.01ms !important}
  .node,.edge{opacity:1 !important}
}