:root{
    --bg:#0B0E14;
    --panel:#12161F;
    --panel-2:#161B26;
    --border:#232A38;
    --text:#D7DCE5;
    --text-dim:#7C8698;
    --mono: 'JetBrains Mono', 'Fira Code', ui-monospace, Menlo, Consolas, monospace;
    --sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

    --stack:#5B9DFF;
    --stack-bg: rgba(91,157,255,0.08);
    --webapi:#E8A33D;
    --webapi-bg: rgba(232,163,61,0.08);
    --micro:#C792EA;
    --micro-bg: rgba(199,146,234,0.08);
    --macro:#4FD6B0;
    --macro-bg: rgba(79,214,176,0.08);
    --danger:#F17878;
    --line-hi: rgba(91,157,255,0.16);
  }
  *{box-sizing:border-box;}
  html{ scroll-behavior:smooth; }
  html,body{ margin:0; background:var(--bg); color:var(--text); font-family:var(--sans); }

  .app-shell{ height:100vh; display:flex; flex-direction:column; overflow:hidden; border-bottom:1px solid var(--border); }

  header{
    display:flex; align-items:center; gap:16px; padding:10px 18px;
    border-bottom:1px solid var(--border); background:linear-gradient(180deg,#0D111A,#0B0E14);
    flex-shrink:0;
  }
  .brand{display:flex; align-items:center; gap:9px; text-decoration:none; color:inherit;}
  .brand svg{display:block;}
  .brand-name{font-weight:700; font-size:15.5px; letter-spacing:0.2px;}
  .brand-sub{font-size:11.5px; color:var(--text-dim); margin-top:-1px;}
  header .spacer{flex:1;}
  header nav{ display:flex; gap:4px; margin-right:6px; }
  header nav a{ font-size:12px; color:var(--text-dim); text-decoration:none; padding:6px 9px; border-radius:6px; }
  header nav a:hover{ color:var(--text); background:var(--panel-2); }
  select, button{
    font-family:var(--sans); font-size:13px; color:var(--text);
    background:var(--panel-2); border:1px solid var(--border); border-radius:7px;
    padding:7px 11px; cursor:pointer; transition:border-color .15s, background .15s;
  }
  select:hover, button:hover{ border-color:#3A4356; }
  button.primary{ background:var(--stack); color:#08101F; border-color:var(--stack); font-weight:600; }
  button.primary:hover{ filter:brightness(1.08); }
  button:disabled{ opacity:0.4; cursor:not-allowed; }
  button.icon{ padding:7px 10px; }

  main{ flex:1; display:flex; min-height:0; }
  .col-editor{ width:42%; min-width:340px; display:flex; flex-direction:column; border-right:1px solid var(--border); }
  .col-viz{ flex:1; display:flex; flex-direction:column; min-width:0; }

  .editor-toolbar{ display:flex; align-items:center; gap:8px; padding:9px 12px; border-bottom:1px solid var(--border); background:var(--panel); }
  .editor-toolbar .grow{flex:1;}
  #customBadge{ font-size:10.5px; color:var(--stack); border:1px solid rgba(91,157,255,0.4); background:var(--stack-bg); padding:2px 7px; border-radius:20px; display:none; }
  .editor-wrap{ position:relative; flex:1; overflow:hidden; background:#0D1117; }
  .gutter-highlight{
    position:absolute; left:0; right:0; height:20px; background:var(--line-hi);
    pointer-events:none; transition: top .12s ease; display:none; border-left:2px solid var(--stack);
  }
  textarea#codeInput{
    position:absolute; inset:0; width:100%; height:100%; resize:none; border:0; outline:0;
    background:transparent; color:#D7DCE5; caret-color:#5B9DFF;
    font-family:var(--mono); font-size:13px; line-height:20px; padding:12px 14px 12px 54px;
    tab-size:2; white-space:pre; overflow:auto;
  }
  .line-numbers{
    position:absolute; left:0; top:0; bottom:0; width:44px; padding:12px 0 12px 0;
    font-family:var(--mono); font-size:13px; line-height:20px; color:#3E4759; text-align:right;
    padding-right:10px; pointer-events:none; user-select:none; overflow:hidden;
    border-right:1px solid var(--border);
  }
  .console-panel{ height:180px; flex-shrink:0; border-top:1px solid var(--border); display:flex; flex-direction:column; background:#0D1117; }
  .console-head{ display:flex; align-items:center; gap:8px; padding:7px 12px; border-bottom:1px solid var(--border); font-size:11.5px; color:var(--text-dim); text-transform:uppercase; letter-spacing:0.06em; }
  .console-body{ flex:1; overflow-y:auto; padding:6px 12px; font-family:var(--mono); font-size:12.5px; line-height:1.65; }
  .console-line{ white-space:pre-wrap; word-break:break-word; border-bottom:1px solid rgba(255,255,255,0.03); padding:2px 0; }
  .console-line.error{ color:var(--danger); }
  .console-line.warn{ color:var(--webapi); }

  .viz-grid{ flex:1; display:grid; grid-template-columns:1fr 1fr; grid-template-rows:1fr 1fr; gap:1px; background:var(--border); min-height:0; }
  .panel{ background:var(--panel); display:flex; flex-direction:column; min-height:0; }
  .panel-head{ display:flex; align-items:center; gap:8px; padding:9px 13px; border-bottom:1px solid var(--border); flex-shrink:0; }
  .dot{ width:8px; height:8px; border-radius:50%; flex-shrink:0; }
  .panel-title{ font-size:12.5px; font-weight:600; letter-spacing:0.02em; }
  .panel-sub{ font-size:10.5px; color:var(--text-dim); margin-left:auto; }
  .panel-body{ flex:1; overflow-y:auto; padding:10px 12px; display:flex; flex-direction:column; gap:6px; }
  .panel-body.stack{ flex-direction:column-reverse; }
  .empty-hint{ color:#414B5E; font-size:12px; font-family:var(--mono); padding:8px 2px; }

  .chip{
    font-family:var(--mono); font-size:12px; padding:8px 10px; border-radius:7px;
    border:1px solid; display:flex; align-items:center; gap:8px; animation: pop .18s ease;
  }
  @keyframes pop{ from{ transform:scale(0.92); opacity:0; } to{ transform:scale(1); opacity:1; } }
  .chip .idx{ font-size:10px; color:var(--text-dim); }
  .chip.stack{ background:var(--stack-bg); border-color:rgba(91,157,255,0.35); color:#BFDBFF; }
  .chip.webapi{ background:var(--webapi-bg); border-color:rgba(232,163,61,0.35); color:#F5D9A8; }
  .chip.micro{ background:var(--micro-bg); border-color:rgba(199,146,234,0.35); color:#EAD3F7; }
  .chip.macro{ background:var(--macro-bg); border-color:rgba(79,214,176,0.35); color:#BEF0DE; }

  #panel-stack .panel-head .dot{ background:var(--stack); }
  #panel-webapi .panel-head .dot{ background:var(--webapi); }
  #panel-micro .panel-head .dot{ background:var(--micro); }
  #panel-macro .panel-head .dot{ background:var(--macro); }

  .transport{
    display:flex; align-items:center; gap:10px; padding:9px 16px; border-top:1px solid var(--border);
    background:var(--panel); flex-shrink:0;
  }
  .transport .texts{ flex:1; min-width:0; }
  .transport .step-desc{ font-size:12.5px; color:var(--text); font-family:var(--mono); overflow:hidden; text-overflow:ellipsis; white-space:nowrap; }
  .transport .step-why{ font-size:11.5px; color:var(--text-dim); overflow:hidden; text-overflow:ellipsis; white-space:nowrap; margin-top:1px; }
  .transport .step-count{ font-size:11px; color:var(--text-dim); font-family:var(--mono); min-width:80px; text-align:right;}
  input[type="range"]{ width:100px; accent-color:var(--stack); }
  .speed-label{ font-size:11px; color:var(--text-dim); white-space:nowrap; }

  ::-webkit-scrollbar{ width:9px; height:9px; }
  ::-webkit-scrollbar-thumb{ background:#232A38; border-radius:5px; }
  ::-webkit-scrollbar-track{ background:transparent; }

  .legend{ display:flex; gap:14px; padding:8px 16px; font-size:11px; color:var(--text-dim); border-top:1px solid var(--border); background:var(--panel); flex-wrap:wrap; }
  .legend span{ display:inline-flex; align-items:center; gap:5px; }
  .legend .sw{ width:8px; height:8px; border-radius:2px; }

  details.notes{ padding:8px 16px 10px; font-size:11.5px; color:var(--text-dim); border-top:1px solid var(--border); background:var(--panel); }
  details.notes summary{ cursor:pointer; color:#8B96AA; }
  details.notes ul{ margin:8px 0 0; padding-left:18px; line-height:1.6; }

  .scroll-cue{ text-align:center; padding:6px; font-size:11px; color:var(--text-dim); border-top:1px solid var(--border); background:var(--panel); }
  .scroll-cue a{ color:var(--stack); text-decoration:none; }
  .scroll-cue a:hover{ text-decoration:underline; }

  /* ---- docs / learn article ---- */
  .docs-wrap{ background:#090B10; }
  .docs{ max-width:820px; margin:0 auto; padding:56px 24px 90px; }
  .docs h1{ font-size:28px; line-height:1.25; margin:0 0 6px; letter-spacing:-0.01em; }
  .docs .lede{ font-size:15px; color:var(--text-dim); line-height:1.7; margin:0 0 34px; max-width:640px; }
  .docs h2{ font-size:20px; margin:52px 0 12px; letter-spacing:-0.005em; scroll-margin-top:20px; border-top:1px solid var(--border); padding-top:36px; }
  .docs section:first-of-type h2{ border-top:0; padding-top:0; }
  .docs h3{ font-size:15px; margin:26px 0 8px; color:#E7EAF0; scroll-margin-top:20px; }
  .docs p{ font-size:14.5px; line-height:1.75; color:#B9C0CE; margin:0 0 14px; }
  .docs ul, .docs ol{ font-size:14.5px; line-height:1.75; color:#B9C0CE; padding-left:22px; margin:0 0 16px; }
  .docs li{ margin-bottom:6px; }
  .docs code{ font-family:var(--mono); font-size:0.87em; background:#161B26; border:1px solid var(--border); padding:1px 5px; border-radius:4px; color:#CFE0FF; }
  .docs pre{ background:#0D1117; border:1px solid var(--border); border-radius:10px; padding:14px 16px; overflow-x:auto; margin:0 0 16px; }
  .docs pre code{ background:none; border:0; padding:0; font-size:12.8px; line-height:1.65; color:#D7DCE5; }
  .docs .callout{ border:1px solid var(--border); background:var(--panel); border-radius:10px; padding:14px 16px; margin:18px 0; font-size:13.5px; color:#C6CCDA; }
  .docs .callout b{ color:var(--text); }
  .toc{ background:var(--panel); border:1px solid var(--border); border-radius:12px; padding:18px 20px; margin:0 0 40px; }
  .toc-title{ font-size:11px; text-transform:uppercase; letter-spacing:0.08em; color:var(--text-dim); margin-bottom:10px; }
  .toc ol{ columns:2; column-gap:28px; margin:0; padding-left:18px; font-size:13.5px; }
  .toc li{ margin-bottom:6px; break-inside:avoid; }
  .toc a{ color:#AAB6C8; text-decoration:none; }
  .toc a:hover{ color:var(--stack); text-decoration:underline; }
  .glossary dt{ font-weight:600; color:var(--text); font-family:var(--mono); font-size:13.5px; margin-top:14px; }
  .glossary dd{ margin:4px 0 0; font-size:14px; color:#B9C0CE; line-height:1.6; }
  .faq-item{ border-bottom:1px solid var(--border); padding:16px 0; }
  .faq-item:last-child{ border-bottom:0; }
  .faq-item h3{ margin:0 0 6px; }
  .step-legend-table{ width:100%; border-collapse:collapse; font-size:13.5px; margin:0 0 18px; }
  .step-legend-table th, .step-legend-table td{ text-align:left; padding:8px 10px; border-bottom:1px solid var(--border); vertical-align:top; }
  .step-legend-table th{ color:var(--text-dim); font-weight:500; font-size:11.5px; text-transform:uppercase; letter-spacing:0.05em; }
  .step-legend-table td.who{ font-family:var(--mono); font-size:12.5px; white-space:nowrap; }
  .swatch{ display:inline-block; width:9px; height:9px; border-radius:2px; margin-right:6px; vertical-align:middle; }
  footer{ text-align:center; padding:26px; font-size:12px; color:var(--text-dim); border-top:1px solid var(--border); }
  footer a{ color:var(--text-dim); }

  @media (max-width: 900px){
    main{ flex-direction:column; }
    .col-editor{ width:100%; min-width:0; height:46%; border-right:0; border-bottom:1px solid var(--border); }
    .toc ol{ columns:1; }
  }