:root{
  --bg:#0d1117; --panel:#161b22; --panel-2:#1b2230; --sheet:#ffffff;
  --line:#28313c; --line-2:#333e4b;
  --ink:#e6edf3; --muted:#8b98a5; --muted-2:#5f6b78;
  --accent:#17b8a6; --accent-ink:#052b28;
  --amber:#f0b429;
  --before:#2f6fed; --after:#0e9488; --arc:#a855f7;
  --start:#22c55e; --end: #ff0000;
  --shadow:0 1px 0 rgba(255,255,255,.03), 0 8px 24px rgba(0,0,0,.35);
  --mono:ui-monospace,"SFMono-Regular",Menlo,Consolas,"Liberation Mono",monospace;
  --ui:system-ui,-apple-system,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
}
*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;background:var(--bg);color:var(--ink);font-family:var(--ui);
  font-size:13px;line-height:1.45;overflow:hidden;
  -webkit-font-smoothing:antialiased;
}

/* ---------- header ---------- */
header.bar{
  height:52px;display:flex;align-items:center;gap:18px;padding:0 16px;
  background:linear-gradient(180deg,#171d26,#12171e);
  border-bottom:1px solid var(--line);position:relative;z-index:5;
}
.brand{display:flex;align-items:center;gap:10px;font-weight:600;letter-spacing:.02em}
.brand .mark{
  width:26px;height:26px;border-radius:6px;display:grid;place-items:center;
  background:radial-gradient(120% 120% at 30% 20%, #03f6de,#0c5f57);
  box-shadow:inset 0 0 0 1px rgba(255,255,255,.12);
}
.brand .mark svg{width:16px;height:16px;display:block}
.brand small{color:var(--muted);font-weight:500;letter-spacing:.06em;text-transform:uppercase;font-size:10px}
.brand b{font-size:14px}

.controls{display:flex;align-items:center;gap:14px;margin-left:6px}
.field{display:flex;align-items:center;gap:7px}
.field label{color:var(--muted);font-size:11px;letter-spacing:.04em;text-transform:uppercase}
.field input,.field select{
  background:#0c1117;color:var(--ink);border:1px solid var(--line-2);border-radius:6px;
  padding:5px 8px;font-family:var(--mono);font-size:12px;width:66px;
}
.field select{width:auto}
.field input:focus,.field select:focus{outline:none;border-color:var(--accent);box-shadow:0 0 0 2px rgba(23,184,166,.18)}

.spacer{flex:1}
.stats{display:flex;gap:8px;align-items:center}
.chip{
  font-family:var(--mono);font-size:11px;color:var(--muted);
  background:#0c1117;border:1px solid var(--line);border-radius:999px;padding:4px 10px;white-space:nowrap;
}
.chip b{color:var(--ink)}
.chip.good b{color:var(--accent)}

button.btn{
  font-family:var(--ui);font-size:12px;font-weight:600;cursor:pointer;
  border:1px solid var(--line-2);background:#10161d;color:var(--ink);
  padding:7px 12px;border-radius:7px;display:inline-flex;align-items:center;gap:7px;
  transition:border-color .12s,background .12s,transform .05s;
}
button.btn:hover{border-color:var(--muted-2);background:#141b23}
button.btn:active{transform:translateY(1px)}
button.btn.primary{background:var(--accent);border-color:transparent;color:var(--accent-ink)}
button.btn.primary:hover{background:#1cc9b6}
button.btn.ghost{background:transparent}
button.btn svg{width:14px;height:14px}
button.btn:disabled{opacity:.5;cursor:not-allowed}

/* ---------- 3-panel workspace ---------- */
main{
  height:calc(100vh - 52px);
  display:grid;
  grid-template-columns:var(--colL,0.26fr) 6px var(--colM,0.48fr) 6px var(--colR,0.26fr);
}
.col{min-width:0;min-height:0;display:flex;flex-direction:column;background:var(--panel);overflow:hidden}
.col.mid{background:#0f141a}
.gutter{background:var(--bg);cursor:col-resize;position:relative}
.gutter::after{content:"";position:absolute;inset:0 2px;border-left:1px solid var(--line);border-right:1px solid var(--line)}
.gutter:hover::after{border-color:var(--accent)}

.col-head{
  height:38px;flex:0 0 auto;display:flex;align-items:center;gap:10px;padding:0 12px;
  border-bottom:1px solid var(--line);background:var(--panel-2);
}
.col-head .title{font-size:11px;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);font-weight:600}
.col-head .title b{color:var(--ink)}
.col-head .actions{margin-left:auto;display:flex;gap:6px}
.col-head .mini{
  font-size:11px;padding:4px 8px;border-radius:6px;border:1px solid var(--line-2);
  background:#10161d;color:var(--ink);cursor:pointer;display:inline-flex;gap:5px;align-items:center;
}
.col-head .mini:hover{border-color:var(--muted-2)}
.col-head .mini svg{width:12px;height:12px}

/* editors */
.editor{flex:1;min-height:0;position:relative}
textarea.code{
  width:100%;height:100%;resize:none;border:0;outline:none;
  background:#0b0f14;color:#c9d3de;font-family:var(--mono);font-size:12px;line-height:1.55;
  padding:12px 14px;white-space:pre;tab-size:2;
}
textarea.code::placeholder{color:var(--muted-2)}
.col.right textarea.code{background:#0a1310;color:#bfe6df}

/* ---------- middle: legend + cards ---------- */
.mid-toolbar{
  flex:0 0 auto;display:flex;align-items:center;gap:16px;padding:8px 12px;
  border-bottom:1px solid var(--line);background:#0f141a;flex-wrap:wrap;
}
.legend{display:flex;align-items:center;gap:14px;color:var(--muted);font-size:11px}
.legend .k{display:inline-flex;align-items:center;gap:6px}
.dot{width:9px;height:9px;border-radius:50%;display:inline-block}
.dot.start{background:var(--start)}
.dot.end{background:var(--end)}
.swatch{width:16px;height:0;border-top:2px solid var(--before);display:inline-block}
.swatch.after{border-top-color:var(--after)}
.swatch.arc{border-top-color:var(--arc);border-top-width:3px}
.arrowk{color:#8b98a5;display:inline-flex;align-items:center;gap:6px}
.arrowsw{color:#64748b;font-weight:800}
.arrowk{color:var(--muted)}
.toggle{display:inline-flex;align-items:center;gap:6px;cursor:pointer;user-select:none}
.toggle input{accent-color:var(--accent)}

.cards{flex:1;min-height:0;overflow:auto;padding:12px;display:flex;flex-direction:column;gap:12px;scroll-behavior:smooth}
.cards::-webkit-scrollbar{width:11px}
.cards::-webkit-scrollbar-thumb{background:#222c37;border-radius:8px;border:3px solid #0f141a}

.card{
  background:var(--panel);border:1px solid var(--line);border-radius:10px;box-shadow:var(--shadow);
  overflow:visible;scroll-margin-top:8px;
}
.card-head{
  display:flex;align-items:center;gap:10px;padding:9px 12px;border-bottom:1px solid var(--line);
  background:linear-gradient(180deg,#1a212b,#151b23);border-radius:10px 10px 0 0;
}
.zbadge{
  font-family:var(--mono);font-weight:700;font-size:12px;color:var(--accent-ink);
  background:var(--accent);border-radius:6px;padding:3px 9px;
}
.zband{font-family:var(--mono);font-size:11px;color:var(--muted)}
.counts{margin-left:auto;display:flex;gap:6px}
.counts .c{font-family:var(--mono);font-size:11px;color:var(--muted);background:#0c1117;border:1px solid var(--line);border-radius:6px;padding:3px 8px}
.counts .c b{color:var(--ink)}
.counts .c.arc b{color:var(--arc)}
.plot{width:100%;background:var(--sheet);border-radius:0 0 10px 10px;overflow:hidden}
.plot .subhdr{
  display:flex;justify-content:space-between;color:#5b6773;font-family:var(--mono);font-size:10px;
  padding:6px 10px 0;letter-spacing:.03em;
}
.plot-mount{width:100%;min-height:320px}
.placeholder{height:320px;display:grid;place-items:center;color:#9aa6b2;font-family:var(--mono);font-size:11px;background:#fbfcfd}

/* empty state */
.empty{
  flex:1;display:grid;place-items:center;color:var(--muted);text-align:center;padding:40px;
}
.empty .big{font-size:15px;color:var(--ink);margin-bottom:6px;font-weight:600}
.empty svg{width:46px;height:46px;color:var(--line-2);margin-bottom:14px}

/* toast */
#toast{
  position:fixed;bottom:18px;left:50%;transform:translateX(-50%) translateY(20px);
  background:#0b0f14;border:1px solid var(--line-2);color:var(--ink);padding:10px 16px;border-radius:8px;
  font-size:12px;box-shadow:var(--shadow);opacity:0;pointer-events:none;transition:.2s;z-index:50;max-width:70vw;
}
#toast.show{opacity:1;transform:translateX(-50%) translateY(0)}
#toast.err{border-color:var(--end);color:#ffd7d7}

.busy{position:fixed;inset:0;background:rgba(8,11,15,.55);display:none;place-items:center;z-index:40}
.busy.show{display:grid}
.spin{width:34px;height:34px;border-radius:50%;border:3px solid var(--line-2);border-top-color:var(--accent);animation:sp 0.8s linear infinite}
@keyframes sp{to{transform:rotate(360deg)}}