:root{
  --bg:#0f1115;
  --panel:#171a21;
  --node-border:#323a48;
  --text:#e8e9ec;
  --muted:#8b93a3;
  --danger:#e5586b;
}
*{box-sizing:border-box;}
html,body{margin:0;height:100%;background:var(--bg);color:var(--text);font-family:'Segoe UI',system-ui,Arial,sans-serif;overflow:hidden;font-size:16px;}

/* ---------- header ---------- */
#topbar{
  position:absolute;top:0;left:0;right:0;height:48px;z-index:20;
  display:flex;align-items:center;justify-content:space-between;padding:6px 14px;
  background:linear-gradient(to bottom, rgba(8,9,12,.55), transparent);
  pointer-events:none;
}
#brand{
  display:flex;align-items:center;gap:8px;color:var(--muted);
  font-size:15px;font-weight:600;letter-spacing:.2px;
}
#brand img{display:block;width:26px;height:26px;}
#tb-right{ pointer-events:auto; display:flex; gap:8px; align-items:center; flex-wrap:wrap; }
.hdrBtn{
  display:flex;align-items:center;gap:7px;height:32px;
  background:rgba(23,26,33,.65);backdrop-filter:blur(6px);
  border:1px solid rgba(255,255,255,.09);color:var(--text);
  padding:0 12px;border-radius:9px;cursor:pointer;font-size:13.5px;white-space:nowrap;
}
.hdrBtn:hover{background:rgba(40,46,58,.85);}
.hdrBtn.iconBtn{ width:32px;padding:0;justify-content:center; }
.hdrBtn svg{width:15px;height:15px;flex-shrink:0;}
.ghostBtn{
  display:flex;align-items:center;justify-content:center;
  width:32px;height:32px;background:transparent;border:none;color:var(--text);
  border-radius:9px;cursor:pointer;
}
.ghostBtn:hover{background:rgba(255,255,255,.09);}
.ghostBtn svg{width:15px;height:15px;flex-shrink:0;}
.toolbarDivider{ width:1px;height:22px;background:rgba(255,255,255,.12); }
#topbar .toolbarDivider{ margin:0 2px; }
.menuWrap{position:relative;}
.popover{
  position:absolute;top:38px;right:0;min-width:190px;
  background:var(--panel);border:1px solid var(--node-border);border-radius:10px;
  padding:6px;box-shadow:0 12px 34px rgba(0,0,0,.45);display:none;z-index:30;
}
.popover.open{display:block;}
.popover button{
  display:flex;align-items:center;gap:9px;width:100%;text-align:left;background:transparent;border:none;
  color:var(--text);padding:9px 10px;border-radius:6px;cursor:pointer;font-size:14px;
}
.popover button:hover{background:#232936;}
.popover button svg{width:16px;height:16px;flex-shrink:0;}
#helpPanel{min-width:290px;max-width:330px;font-size:13.5px;line-height:1.65;color:var(--muted);padding:15px;cursor:default;}
#helpPanel b{color:var(--text);}
#helpPanel div{margin-bottom:9px;}
#helpPanel .warn{
  color:var(--danger);padding-bottom:9px;margin-bottom:9px;
  border-bottom:1px solid rgba(255,255,255,.1);
}
#helpPanel .warn b{color:var(--danger);}

/* ---------- canvas ---------- */
#canvas{
  position:absolute;top:0;left:0;right:0;bottom:0;
  overflow:hidden;cursor:grab;
  background-image:radial-gradient(circle, #1a1e26 1px, transparent 1px);
  background-size:26px 26px;
}
#canvas.panning{cursor:grabbing;}
#canvas.reparenting, #canvas.reparenting .node{cursor:grabbing;}

#world{ position:absolute;left:0;top:0;transform-origin:0 0;will-change:transform; }
#world.animate{ transition: transform .38s cubic-bezier(.2,.8,.2,1); }

svg#edges{position:absolute;left:0;top:0;overflow:visible;pointer-events:none;}
svg#edges path{
  fill:none;stroke-width:2.2;opacity:.55;transition:stroke-width .25s, opacity .25s;
}
svg#edges path.active{stroke-width:3.4;opacity:1;}
svg#edges path.secondary{opacity:.6;}
svg#edges path.dim{opacity:.1;}
svg#edges .dragLine{stroke:#8b93a3;stroke-width:2;stroke-dasharray:7 6;}

/* ---------- node blocks ---------- */
.node{
  position:absolute;left:0;top:0;
  transform:translate(calc(-50% + var(--node-dx,0px)), calc(-50% + var(--node-dy,0px))) scale(var(--node-scale,1));
  min-width:170px;max-width:270px;
  background:linear-gradient(155deg,#1e2431,#161a22);
  border:1px solid rgba(255,255,255,.08);
  border-radius:16px;
  padding:14px 17px;
  cursor:pointer;
  box-shadow:0 4px 14px rgba(0,0,0,.35), inset 0 1px 0 rgba(255,255,255,.04);
  transition:box-shadow .2s ease, border-color .2s ease, opacity .25s ease, transform .16s ease;
}
.node:hover{ border-color:rgba(255,255,255,.24); }

/* Hover-to-read: --hover-scale is recomputed in JS on every pan/zoom to
   whatever factor brings a node back to ~1:1 on screen, so nodes stay
   legible even when the whole map is zoomed way out. The hovered node
   lifts above its neighbors, and a dimmed one comes back to full
   opacity — no point magnifying something at 16% opacity. */
.node.onPath{ --node-scale:1.05; }
.node:hover{
  --node-scale:var(--hover-scale,1.08);
  --node-dx:var(--hover-dx,0px);
  --node-dy:var(--hover-dy,0px);
  z-index:50;
}
.node.dim:hover{ opacity:1; }
.node:hover .preview{ max-height:260px; }
/* Mid-pan / mid-reparent the map slides under the cursor, so suppress the
   magnify to avoid nodes flickering bigger as they pass beneath it. */
#canvas.panning .node:hover, #canvas.reparenting .node:hover{
  --node-scale:1; --node-dx:0px; --node-dy:0px; z-index:auto;
}
.node.root{
  background:linear-gradient(155deg,#22304a,#1a2436);
  border-color:rgba(255,255,255,.14);
  text-align:center;
  padding:20px 26px;
  border-radius:20px;
}
.node.dim{ opacity:.16; }
.node.dragSource{ opacity:.4; }
.node.drop-target{ box-shadow:0 0 0 3px #4fc3f7, 0 10px 26px rgba(0,0,0,.5); border-color:#4fc3f7; }

.node .label-row{ display:flex; align-items:center; gap:8px; justify-content:flex-start; }
.node.root .label-row{ justify-content:center; }
.node .dot{
  width:9px;height:9px;border-radius:50%;flex-shrink:0;
  background:var(--branch-color, var(--muted));
  box-shadow:0 0 7px var(--branch-color, transparent);
}
.node .root-icon{ opacity:.55; width:16px;height:16px;flex-shrink:0; }
.node .has-notes-icon{ opacity:.4; width:13px;height:13px;flex-shrink:0; }
.node .label{
  font-size:19px;font-weight:600;line-height:1.35;letter-spacing:.1px;
  word-break:normal;overflow-wrap:break-word;outline:none;color:#eef0f3;
}
.node.root .label{ font-size:23px;font-weight:700; }
.node .label[contenteditable="true"]{
  cursor:text;background:#0f1218;border:1px solid #667;border-radius:4px;padding:2px 4px;
}

.node .preview{
  margin-top:9px;font-size:15px;color:var(--muted);line-height:1.5;
  max-height:88px;overflow:hidden;padding-top:9px;border-top:1px solid rgba(255,255,255,.07);
}

.node .controls{ display:flex;gap:5px;margin-top:10px;opacity:0;transform:translateY(2px);transition:opacity .15s, transform .15s; }
.node:hover .controls{opacity:1;transform:translateY(0);}
.node .controls button{
  display:flex;align-items:center;justify-content:center;
  width:28px;height:28px;
  background:rgba(255,255,255,.05);border:1px solid rgba(255,255,255,.08);color:var(--text);
  border-radius:7px;cursor:pointer;
}
.node .controls button:hover{background:rgba(255,255,255,.14);}
.node .controls button.danger:hover{background:var(--danger);border-color:var(--danger);color:#fff;}
.node .controls button.trashRight{margin-left:auto;}
.node .controls svg{width:15px;height:15px;}

/* ---------- shared modal base (editor + viewer) ---------- */
#editorOverlay, #viewerOverlay{
  position:fixed;inset:0;background:rgba(6,7,10,.72);z-index:100;
  display:none;align-items:flex-start;justify-content:center;
  padding-top:clamp(8px, 1vh, 60px);
}
#editorOverlay.open, #viewerOverlay.open{display:flex;}
#editorModal, #viewerModal{
  width:min(980px,92vw);max-height:92vh;display:flex;flex-direction:column;
  background:var(--panel);border:1px solid var(--node-border);border-radius:14px;
  box-shadow:0 24px 70px rgba(0,0,0,.55);overflow:hidden;
}
#editorBody, #viewerBody{ flex:1;overflow:auto; }
#editorBody mark, #viewerBody mark{border-radius:3px;padding:0 2px;}
#editorBody ul, #viewerBody ul{padding-left:30px;margin:10px 0;}
#editorBody li, #viewerBody li{margin:6px 0;}
#editorBody p, #viewerBody p{margin:0 0 12px;}
#editorBody p:last-child, #viewerBody p:last-child{margin-bottom:0;}

/* ---------- edit-mode notes editor ---------- */
#editorHeader{
  padding:16px 20px;border-bottom:1px solid var(--node-border);
  display:flex;align-items:center;gap:10px;color:var(--muted);
}
#editorHeader svg{width:18px;height:18px;flex-shrink:0;}
#editorHeader .name{font-weight:600;font-size:16px;flex:1;color:var(--text);}
#editorToolbar{
  padding:10px 20px;border-bottom:1px solid var(--node-border);
  background:rgba(255,255,255,.015);
}
#editorToolbar .hint{font-size:12.5px;color:var(--muted);}
#editorBody{ padding:26px 30px;font-size:28px;line-height:1.55;outline:none;color:#f1f2f4; }
#editorBody:empty:before{ content:"Start typing your notes…";color:var(--muted);font-style:italic; }
#editorFooter{ padding:14px 20px;border-top:1px solid var(--node-border);display:flex;justify-content:flex-end;gap:8px; }
#editorFooter button{ padding:9px 20px;border-radius:8px;border:1px solid var(--node-border);background:#232936;color:var(--text);cursor:pointer;font-size:14px; }
#editorFooter button.primary{background:#f5a623;color:#241a04;border-color:#f5a623;font-weight:600;}

/* ---------- present-mode read-only viewer ---------- */
#viewerHeaderBar{
  padding:16px 20px;border-bottom:1px solid var(--node-border);
  display:flex;align-items:center;gap:10px;
}
#viewerHeaderBar .name{font-weight:700;font-size:19px;flex:1;color:var(--text);}
#viewerBody{ padding:30px 34px;font-size:30px;line-height:1.6;color:#f1f2f4; }

#fileInput{display:none;}

@media (max-width:480px){
  #editorBody{font-size:21px;padding:18px;}
  #viewerBody{font-size:22px;padding:20px;}
  .node{max-width:200px;}
  .hdrBtn{padding:0 8px;font-size:13px;}
  #brand span{display:none;}
}