:root{
  --bg:#0c0f14; --panel:#131820; --panel-2:#1a2230; --line:#242e3e;
  --ink:#e8eef7; --muted:#8a99ad; --dim:#5d6b7f;
  --accent:#4dd4c4; --accent-dim:#1f5f58;
  --warn:#f0a842; --bad:#f0655d; --good:#57c98a;
  --mono:ui-monospace,SFMono-Regular,"SF Mono",Menlo,monospace;
}
*{box-sizing:border-box}
html,body{margin:0;height:100%}
body{
  background:var(--bg); color:var(--ink); font:15px/1.5 system-ui,-apple-system,sans-serif;
  display:flex; flex-direction:column; overflow:hidden;
}
header{
  display:flex; align-items:center; gap:11px; padding:12px 20px;
  border-bottom:1px solid var(--line); background:var(--panel); flex:none;
}
.logo{font:700 20px/1 var(--mono); letter-spacing:.14em; color:var(--accent)}
.tag{color:var(--muted); font-size:13px}
header .sp{flex:1}
.pill{
  font:600 11px/1 var(--mono); letter-spacing:.08em; text-transform:uppercase;
  padding:5px 9px; border-radius:999px; border:1px solid var(--line); color:var(--muted);
}
.pill.on{color:var(--accent); border-color:var(--accent-dim); background:#0f2a27}

main{flex:1; display:grid; grid-template-columns:270px 1fr 400px; min-height:0}
aside,.trace-col{overflow-y:auto; background:var(--panel)}
aside{border-right:1px solid var(--line); padding:18px}
.trace-col{border-left:1px solid var(--line); display:flex; flex-direction:column}
.center{display:flex; flex-direction:column; min-width:0; overflow-y:auto}

h2{font:600 11px/1 var(--mono); letter-spacing:.12em; text-transform:uppercase;
   color:var(--dim); margin:0 0 12px}
.field{margin-bottom:14px}
label{display:block; font-size:12px; color:var(--muted); margin-bottom:5px}
input[type=number]{
  width:100%; background:var(--bg); color:var(--ink); border:1px solid var(--line);
  border-radius:6px; padding:8px 10px; font:13px var(--mono);
}
input[type=number]:focus,.sel-btn:focus,.file-btn:focus{
  outline:none; border-color:var(--accent); box-shadow:0 0 0 3px rgba(77,212,196,.13);
}

/* Custom select. A native <select> renders its open list with the OS widget, which
   cannot be themed and breaks the dark UI, so the list is built in the DOM. */
.sel{position:relative}
.sel-btn{
  width:100%; display:flex; align-items:center; gap:8px; text-align:left;
  background:var(--bg); color:var(--ink); border:1px solid var(--line);
  border-radius:6px; padding:8px 10px; font:13px var(--mono); cursor:pointer;
}
.sel-btn .val{flex:1; overflow:hidden; text-overflow:ellipsis; white-space:nowrap}
.sel-btn .chev{
  width:0; height:0; flex:none; border-left:4.5px solid transparent;
  border-right:4.5px solid transparent; border-top:5px solid var(--muted);
  transition:transform .15s;
}
.sel.open .sel-btn{border-color:var(--accent)}
.sel.open .chev{transform:rotate(180deg)}
.sel-list{
  position:absolute; z-index:40; top:calc(100% + 4px); left:0; right:0;
  background:var(--panel-2); border:1px solid var(--accent-dim); border-radius:8px;
  padding:4px; box-shadow:0 12px 28px rgba(0,0,0,.55); max-height:230px; overflow-y:auto;
}
.sel-list[hidden]{display:none}
.sel-opt{
  display:flex; align-items:center; gap:8px; padding:7px 9px; border-radius:5px;
  font:13px var(--mono); color:var(--muted); cursor:pointer;
}
.sel-opt:hover{background:var(--bg); color:var(--ink)}
.sel-opt.sel-on{color:var(--accent); background:#0f2a27}
.sel-opt .tick{width:11px; flex:none; color:var(--accent)}
.sel-opt .sub{margin-left:auto; font-size:11px; color:var(--dim)}

/* Custom file input. The native control renders an OS button that cannot be themed. */
input[type=file]{position:absolute; width:1px; height:1px; opacity:0; pointer-events:none}
.file-btn{
  width:100%; display:flex; align-items:center; gap:9px;
  background:var(--bg); color:var(--muted); border:1px dashed var(--line);
  border-radius:6px; padding:10px; font:13px var(--mono); cursor:pointer;
}
.file-btn:hover{border-color:var(--accent-dim); color:var(--ink)}
.file-btn.has{border-style:solid; border-color:var(--accent-dim); color:var(--ink)}
.file-btn .ico{color:var(--accent); font:14px/1 var(--mono); flex:none}
.file-btn .nm{flex:1; overflow:hidden; text-overflow:ellipsis; white-space:nowrap}
.file-btn .sz{font-size:11px; color:var(--dim); flex:none}
input[type=range]{width:100%; accent-color:var(--accent)}
button{
  width:100%; padding:11px; border-radius:7px; border:1px solid var(--accent-dim);
  background:var(--accent); color:#05201d; font:700 14px system-ui; cursor:pointer;
}
button:hover{filter:brightness(1.08)}
button:disabled{opacity:.45; cursor:not-allowed}
button.ghost{background:transparent; color:var(--muted); border-color:var(--line); font-weight:500}
hr{border:0; border-top:1px solid var(--line); margin:20px 0}

.charts{padding:18px; display:flex; flex-direction:column; gap:14px}
.card{background:var(--panel); border:1px solid var(--line); border-radius:10px; padding:14px}
.card h3{margin:0 0 4px; font:600 13px system-ui}
.card .sub{color:var(--dim); font-size:12px; margin-bottom:10px}
canvas{width:100%; display:block}

.stats{display:grid; grid-template-columns:repeat(auto-fit,minmax(110px,1fr)); gap:10px}
.stat{background:var(--panel-2); border-radius:8px; padding:10px 12px}
.stat .k{font-size:11px; color:var(--dim); text-transform:uppercase; letter-spacing:.06em}
.stat .v{font:600 19px var(--mono); margin-top:3px}
.stat .v.small{font-size:14px}

.trace-head{padding:16px 18px 10px; border-bottom:1px solid var(--line)}
.steps{padding:14px 18px; display:flex; flex-direction:column; gap:12px}
.step{border-left:2px solid var(--line); padding:2px 0 2px 14px; position:relative}
.step::before{content:""; position:absolute; left:-5px; top:6px; width:8px; height:8px;
  border-radius:50%; background:var(--line)}
.step.re_acquire{border-color:var(--warn)} .step.re_acquire::before{background:var(--warn)}
.step.report{border-color:var(--good)} .step.report::before{background:var(--good)}
.step.escalate{border-color:var(--bad)} .step.escalate::before{background:var(--bad)}
.step.acquiring{border-color:var(--accent)} .step.acquiring::before{background:var(--accent)}
.step .hd{display:flex; align-items:baseline; gap:8px; margin-bottom:3px}
.step .n{font:700 11px var(--mono); color:var(--dim)}
.step .act{font:700 11px var(--mono); letter-spacing:.09em; text-transform:uppercase}
.re_acquire .act{color:var(--warn)} .report .act{color:var(--good)}
.escalate .act{color:var(--bad)} .acquiring .act{color:var(--accent)}
.step .meta{font:12px var(--mono); color:var(--dim); margin-bottom:5px}
.step .why{font-size:13px; color:var(--ink); opacity:.92}
.badges{display:flex; flex-wrap:wrap; gap:5px; margin-top:7px}
.badge{font:600 10px var(--mono); letter-spacing:.05em; padding:3px 7px; border-radius:4px;
  background:#2a1d1d; color:var(--bad); border:1px solid #3d2626}
.badge.ok{background:#14291f; color:var(--good); border-color:#1f3d2d}

.verdict{margin:0 18px 18px; border-radius:10px; padding:16px; border:1px solid var(--line);
  background:var(--panel-2)}
.verdict.report{border-color:var(--good); background:#102019}
.verdict.escalate{border-color:var(--bad); background:#20100f}
.verdict .lab{font:600 11px var(--mono); letter-spacing:.1em; text-transform:uppercase; color:var(--dim)}
.verdict .fault{font:700 22px system-ui; margin:5px 0 2px; text-transform:capitalize}
.verdict .conf{font:13px var(--mono); color:var(--muted)}
.verdict .truth{margin-top:11px; padding-top:11px; border-top:1px solid var(--line);
  font:12px var(--mono); color:var(--dim)}
.verdict .truth b{color:var(--ink)}
.hint{color:var(--dim); font-size:12px; line-height:1.55}
.err{color:var(--bad); font:12px var(--mono); margin-top:8px; white-space:pre-wrap}
.spin{display:inline-block; width:10px; height:10px; border:2px solid var(--accent-dim);
  border-top-color:var(--accent); border-radius:50%; animation:sp .7s linear infinite}
@keyframes sp{to{transform:rotate(360deg)}}
.tabs{display:flex; gap:4px; margin-bottom:16px}
.tabs button{flex:1; padding:7px; font-size:12px; font-weight:600;
  background:transparent; color:var(--muted); border:1px solid var(--line)}
.tabs button.sel{background:var(--panel-2); color:var(--accent); border-color:var(--accent-dim)}


/* ---- accessibility ---------------------------------------------------------
   The custom select and file control replace native elements that were keyboard
   and screen-reader accessible by default; these rules restore what the swap
   removed. */
.sr-only{
  position:absolute; width:1px; height:1px; padding:0; margin:-1px;
  overflow:hidden; clip:rect(0 0 0 0); white-space:nowrap; border:0;
}
.skip{
  position:absolute; left:-9999px; top:8px; z-index:100;
  background:var(--accent); color:#05201d; padding:9px 14px; border-radius:6px;
  font:600 13px system-ui;
}
.skip:focus{left:8px}
.sel-opt.sel-active{outline:2px solid var(--accent); outline-offset:-2px}
.sel-list:focus{outline:none}
:focus-visible{outline:2px solid var(--accent); outline-offset:2px}
/* the dim/muted greys are decorative only; nothing conveys meaning by colour alone */
@media (prefers-reduced-motion: reduce){
  *,*::before,*::after{animation-duration:.01ms !important; animation-iteration-count:1 !important;
    transition-duration:.01ms !important; scroll-behavior:auto !important}
}
@media (prefers-contrast: more){
  :root{--muted:#c3cede; --dim:#9fb0c4; --line:#4a5a70}
}