:root{
  --bg:#F8FAFC;
  --panel:#FFFFFF;
  --panel2:#F1F5F9;
  --line:#E2E8F0;
  --line-soft:#EDF1F6;
  --text:#0F172A;
  --muted:#64748B;
  --arc:#1868C2;             /* the accent; historical name kept on purpose */
  --arc-dim:rgba(24,104,194,.10);
  --amber:#B45309;
  --danger:#DC2626;
  --radius:8px;
  --font-body:system-ui,-apple-system,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;
  --font-display:system-ui,-apple-system,'Segoe UI',Roboto,Helvetica,Arial,sans-serif;
  --font-mono:ui-monospace,'Cascadia Mono',Consolas,Menlo,monospace;
}
*{box-sizing:border-box;margin:0;padding:0}
body{
  background:var(--bg);
  color:var(--text);
  font-family:var(--font-body);
  font-size:13.5px;
}
/* The tracer keeps its own full-viewport shell; marketing copy scrolls below it. */
.app-shell{
  height:100vh;
  display:flex;
  flex-direction:column;
  overflow:hidden;
}

/* ---------- header ---------- */
header{
  display:flex;align-items:center;gap:14px;
  padding:10px 16px;
  border-bottom:1px solid var(--line);
  background:var(--panel);
  flex:0 0 auto;
}
.wordmark{
  font-weight:700;
  font-size:17px;
  letter-spacing:-.01em;
}
.wordmark .arc{color:var(--arc)}
.tagline{
  color:var(--muted);
  font-size:12px;
  border-left:1px solid var(--line);
  padding-left:14px;
}
header .spacer{flex:1}
.btn{
  font-family:var(--font-body);
  font-size:13px;font-weight:600;
  color:var(--text);
  background:var(--panel);
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:7px 14px;
  cursor:pointer;
  transition:background .12s ease,border-color .12s ease;
}
.btn:hover{background:var(--panel2);border-color:#CBD5E1}
.btn:focus-visible{outline:2px solid var(--arc);outline-offset:2px}
.btn.primary{
  background:var(--arc);
  border-color:var(--arc);
  color:#FFFFFF;
}
.btn.primary:hover{background:#12549E;border-color:#12549E}
.btn.primary:disabled{
  background:#E2E8F0;border-color:#E2E8F0;color:#94A3B8;cursor:not-allowed;
}
.btn.small{padding:4px 10px;font-size:12px;font-weight:500}
.btn.small:disabled{color:#94A3B8;cursor:not-allowed;background:#F1F5F9}

/* ---------- layout ---------- */
main{flex:1;display:flex;min-height:0}
aside{
  scrollbar-width:thin;scrollbar-color:#C4CCD4 transparent;
  width:280px;flex:0 0 280px;
  background:#EDF0F3;
  border-right:1px solid var(--line);
  overflow-y:auto;
  padding:12px;
  display:flex;flex-direction:column;gap:12px;
}
aside .group{
  background:var(--panel);
  border:1px solid var(--line);
  border-radius:10px;
  padding:12px 14px 14px;
}
.stage{flex:1;display:flex;flex-direction:column;min-width:0}
.viewbar{
  display:flex;align-items:center;gap:10px;
  padding:8px 12px;
  border-bottom:1px solid var(--line-soft);
  flex:0 0 auto;
  flex-wrap:wrap;
}
.seg{display:flex;background:var(--panel2);border:1px solid var(--line);border-radius:var(--radius);overflow:hidden}
.seg button{
  font-family:var(--font-body);font-size:12px;font-weight:500;
  color:var(--muted);background:transparent;border:none;
  padding:6px 13px;cursor:pointer;
}
.seg button.active{background:var(--panel);color:var(--text);box-shadow:inset 0 0 0 1px var(--line)}
.seg button.active.keep{color:#15803D}
.seg button.active.erase{color:var(--danger)}
.seg button:focus-visible{outline:2px solid var(--arc);outline-offset:-2px}
.brushrow{display:flex;align-items:center;gap:7px}
.brushrow input[type=range]{width:90px}
.brushrow .readout{font-size:11.5px;color:var(--muted);min-width:88px;font-variant-numeric:tabular-nums}
.viewbar .hint{color:var(--muted);font-size:11.5px;margin-left:auto}
@media (max-width:1100px){.viewbar .hint{display:none}}

.canvas-wrap{flex:1;position:relative;min-height:0;background:#EDF0F3}
#stageCanvas{position:absolute;inset:0;width:100%;height:100%;cursor:grab}
#stageCanvas.panning{cursor:grabbing}
#stageCanvas.brushing{cursor:crosshair}
#stageCanvas.picking{cursor:pointer}
.readout.editable{cursor:text}
.readout.editable:hover{border-color:var(--arc)}
.readout-edit{width:62px;font-size:12px;color:var(--text);text-align:right;
  font-variant-numeric:tabular-nums;
  background:#FFFFFF;border:1px solid var(--arc);border-radius:5px;padding:2px 6px}

/* empty state / dropzone */
.dropzone{
  position:absolute;inset:24px;
  border:1.5px dashed #C3CCD4;
  border-radius:12px;
  display:flex;flex-direction:column;align-items:center;justify-content:center;gap:10px;
  color:var(--muted);
  cursor:pointer;
  transition:border-color .15s ease,background .15s ease;
}
.dropzone:hover,.dropzone.over{border-color:var(--arc);background:var(--arc-dim)}
.dropzone .big{font-size:21px;font-weight:600;
  letter-spacing:-.01em;color:var(--text)}
.dropzone .sub{font-size:13px;max-width:420px;text-align:center;line-height:1.5}
.dropzone.hidden{display:none}

/* ---------- DRO strip ---------- */
.dro{
  flex:0 0 auto;
  display:flex;gap:0;flex-wrap:wrap;
  border-top:1px solid var(--line);
  background:var(--panel);
}
.dro .cell{
  padding:9px 18px;
  border-right:1px solid var(--line-soft);
  display:flex;flex-direction:column;gap:1px;
  min-width:104px;
}
.dro .lab{font-size:9.5px;letter-spacing:.14em;color:var(--muted);text-transform:uppercase;font-family:var(--font-body);font-weight:600}
.dro .val{font-size:14.5px;color:var(--arc);font-weight:600;font-variant-numeric:tabular-nums}
.dro .val.plain{color:var(--text)}
.dro .val.warn{color:var(--danger)}
.dro .status{margin-left:auto;border-right:none;justify-content:center;min-width:200px;flex:1 1 200px}
.dro .status .val{font-size:11.5px;color:var(--muted);font-weight:400;white-space:normal;line-height:1.4;overflow:visible}
.dro .status .val.warn{color:#B45309}

/* ---------- controls ---------- */
.group h2{
  font-size:12.5px;font-weight:600;
  color:var(--text);
  margin:0 0 11px;padding-bottom:8px;
  border-bottom:1px solid var(--line-soft);
}
.ctl{margin-bottom:12px}
.ctl:last-child{margin-bottom:0}
.ctl .row{display:flex;justify-content:space-between;align-items:center;margin-bottom:6px;gap:8px}
.ctl label{font-size:13px;font-weight:400;color:#334155}
.ctl .readout{
  font-size:12px;color:var(--text);
  font-variant-numeric:tabular-nums;
  background:#F6F8FA;border:1px solid var(--line);border-radius:5px;
  padding:2px 8px;min-width:58px;text-align:right;white-space:nowrap;
}
input[type=range]{
  -webkit-appearance:none;appearance:none;
  width:100%;height:5px;border-radius:3px;
  background:#D9DFE5;outline:none;cursor:pointer;
}
input[type=range]::-webkit-slider-thumb{
  -webkit-appearance:none;appearance:none;
  width:14px;height:14px;border-radius:50%;
  background:var(--arc);border:2px solid #FFFFFF;
  cursor:pointer;
}
input[type=range]::-moz-range-thumb{
  width:12px;height:12px;border-radius:50%;
  background:var(--arc);border:2px solid #FFFFFF;cursor:pointer;
}
input[type=range]:focus-visible{outline:2px solid var(--arc);outline-offset:4px}
.check{display:flex;align-items:center;gap:8px;font-size:13px;color:#334155;cursor:pointer;user-select:none}
.check input{accent-color:var(--arc);width:15px;height:15px;cursor:pointer;flex:0 0 auto}
.outrow{display:flex;gap:8px;align-items:center}
input[type=number]{
  width:90px;
  font-size:13px;font-variant-numeric:tabular-nums;
  color:var(--text);background:#FFFFFF;
  border:1px solid var(--line);border-radius:6px;
  padding:6px 8px;
}
input[type=number].mini{width:64px;padding:4px 6px;font-size:12px}
input[type=number]:focus-visible{outline:2px solid var(--arc);outline-offset:1px}
select{
  font-family:var(--font-body);font-size:12.5px;
  color:var(--text);background:#FFFFFF;
  border:1px solid var(--line);border-radius:6px;
  padding:6px 8px;cursor:pointer;
}
select:focus-visible{outline:2px solid var(--arc);outline-offset:1px}
.dim-note{font-family:var(--font-mono);font-size:11.5px;color:var(--muted);margin-top:6px}
.export-note{font-size:11.5px;color:var(--muted);line-height:1.5;margin-top:10px}
.linklike{background:none;border:none;color:var(--arc);font-size:11.5px;cursor:pointer;padding:0;text-decoration:underline;text-underline-offset:2px;font-family:var(--font-body)}
.linklike:focus-visible{outline:2px solid var(--arc);outline-offset:2px}
.thinrow{display:flex;align-items:center;gap:6px;margin-top:7px;padding-left:23px}
.thinrow .unitlab{font-family:var(--font-mono);font-size:12px;color:var(--muted)}
aside .fill{flex:1}
aside .tip{font-size:11.5px;color:var(--muted);line-height:1.55;border-top:1px solid var(--line-soft);padding-top:10px}
.hiddenrow{display:none!important}

/* ---------- modal ---------- */
.modal{position:fixed;inset:0;background:rgba(15,23,42,.45);display:none;align-items:center;justify-content:center;z-index:50}
.modal.open{display:flex}
.modal .box{
  width:min(680px,92vw);max-height:82vh;
  background:var(--panel);border:1px solid var(--line);border-radius:12px;
  padding:18px;display:flex;flex-direction:column;gap:12px;
}
.modal h3{font-size:16px;font-weight:600;letter-spacing:-.01em;margin:0}
.modal textarea{
  flex:1;min-height:300px;resize:vertical;
  font-family:var(--font-mono);font-size:11.5px;line-height:1.4;
  color:var(--text);background:#F8FAFC;
  border:1px solid var(--line);border-radius:8px;padding:10px;
}
.modal .actions{display:flex;gap:8px;justify-content:flex-end}

@media (prefers-reduced-motion:reduce){*{transition:none!important}}
@media (max-width:760px){
  main{flex-direction:column}
  aside{width:100%;flex:0 0 auto;border-right:none;border-bottom:1px solid var(--line);max-height:44vh}
}

/* ---------- credit counter + paywall ---------- */
.credits{
  font-size:12.5px;font-weight:500;
  color:var(--muted);
  border:1px solid var(--line);border-radius:999px;
  padding:4px 11px;white-space:nowrap;
}
.credits.out{color:var(--amber);border-color:#EBD1AA}
.credits.licensed{color:#15803D;border-color:#BBE0C8}

.modal .box.pay{width:min(520px,92vw)}
.modal .box.pay h3{color:var(--text)}
.modal .box.pay p{font-size:13.5px;line-height:1.6;color:#334155;margin-bottom:9px}
.modal .box.pay p:last-child{margin-bottom:0}
.modal .box.pay strong{color:var(--text)}
.paynote{font-size:11.5px;color:var(--muted);line-height:1.5;min-height:1em}
.payactions{display:flex;flex-direction:column;gap:8px}
.payactions .btn{width:100%;padding:10px 14px;font-size:13.5px}
.paykey{
  border-top:1px solid var(--line-soft);padding-top:12px;
  display:flex;flex-direction:column;gap:7px;
}
.paykey .lab{font-size:11.5px;color:var(--muted)}
.paykey .row{display:flex;gap:7px}
.paykey input{
  flex:1;font-size:12.5px;
  color:var(--text);background:#FFFFFF;
  border:1px solid var(--line);border-radius:6px;padding:7px 9px;
}
.paykey input:focus-visible{outline:2px solid var(--arc);outline-offset:1px}
.paykey .msg{font-size:11.5px;color:var(--muted);min-height:1em}

/* Bait for ad-blocker detection. Off-screen, inert, never shown to anyone. */
.adsbox{position:absolute;left:-9999px;top:-9999px;pointer-events:none}

/* ---------- tooltips ---------- */
.apptip{
  position:fixed;z-index:120;max-width:280px;
  background:#0F172A;color:#F1F5F9;
  font-family:var(--font-body);font-size:12.5px;line-height:1.5;font-weight:400;
  padding:8px 11px;border-radius:7px;
  pointer-events:none;opacity:0;transform:translateY(2px);
  transition:opacity .14s ease,transform .14s ease;
}
.apptip.show{opacity:1;transform:none}

/* until an image is loaded, the controls are not the story */
.no-image aside .group{opacity:.5;pointer-events:none}
.no-image aside .tip{opacity:.8}

.btn.tiny{padding:2px 9px;font-size:11.5px;font-weight:600}

/* ---------- loading indicators ---------- */
.busybar{
  position:absolute;top:0;left:0;right:0;height:3px;z-index:5;
  background:repeating-linear-gradient(90deg,var(--arc) 0 22px,#BFD7F2 22px 44px);
  background-size:44px 3px;
  opacity:0;transition:opacity .12s ease;pointer-events:none;
  animation:busymove .8s linear infinite;
}
.canvas-wrap.busy .busybar{opacity:1}
.canvas-wrap.busy{cursor:progress}
@keyframes busymove{to{background-position:44px 0}}

.btn.loading{position:relative;color:transparent}
.btn.loading::after{
  content:'';position:absolute;inset:0;margin:auto;
  width:14px;height:14px;border-radius:50%;
  border:2px solid rgba(255,255,255,.45);border-top-color:#fff;
  animation:btnspin .7s linear infinite;
}
@keyframes btnspin{to{transform:rotate(360deg)}}
@media (prefers-reduced-motion:reduce){.busybar,.btn.loading::after{animation:none}}

/* click-to-copy licence key chip */
.keycopy{
  display:flex;align-items:center;gap:12px;width:100%;
  background:#F6F8FA;border:1px solid var(--line);border-radius:8px;
  padding:10px 12px;margin:2px 0 10px;cursor:pointer;
  font-family:var(--font-body);text-align:left;
  transition:border-color .16s ease;
}
.keycopy:hover{border-color:var(--arc)}
.keycopy code{
  flex:1;background:none;border:none;padding:0;
  font-size:14px;letter-spacing:.03em;color:var(--text);
  font-variant-numeric:tabular-nums;
}
.keycopy span{font-size:12.5px;font-weight:600;color:var(--arc);white-space:nowrap}
.keycopy.copied span{color:#15803D}

/* header units toggle */
.unitsel{
  font-family:var(--font-body);font-size:13px;font-weight:500;
  color:var(--text);background:var(--panel);
  border:1px solid var(--line);border-radius:var(--radius);
  padding:6px 8px;cursor:pointer;
}
.unitsel:focus-visible{outline:2px solid var(--arc);outline-offset:1px}

.unitsrow{
  display:flex;align-items:center;justify-content:space-between;gap:10px;
  background:var(--panel);border:1px solid var(--line);border-radius:10px;
  padding:8px 14px;
}
.unitsrow label{font-size:13px;color:#334155}