:root{
    --bg:#0b0e14; --panel:#11151f; --panel2:#161b27; --border:#222a3a;
    --fg:#d7dce5; --muted:#8a93a6; --accent:#5db8ff; --accent2:#7c5cff;
    --ok:#41d39a; --err:#ff6b6b; --warn:#ffd166;
    --mono:ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
    --user:#16203a; --asst:#11151f;
  }
  *{box-sizing:border-box}
  html,body{margin:0;height:100%}
  body{background:var(--bg);color:var(--fg);font:15px/1.6 system-ui,-apple-system,Segoe UI,Roboto,sans-serif;display:flex;flex-direction:column}
  a{color:var(--accent);text-decoration:none}
  a:hover{text-decoration:underline}

  header{display:flex;align-items:center;gap:12px;padding:11px 18px;border-bottom:1px solid var(--border);background:linear-gradient(180deg,#0d1119,#0b0e14);flex-wrap:wrap}
  .logo{font-weight:700;font-size:17px;letter-spacing:.3px;white-space:nowrap}
  .logo b{background:linear-gradient(90deg,var(--accent),var(--accent2));-webkit-background-clip:text;background-clip:text;color:transparent}
  .tag{color:var(--muted);font-size:12.5px;white-space:nowrap}
  header .spacer{flex:1}
  header select,header button{font:inherit;font-size:13px;color:var(--fg);background:var(--panel2);border:1px solid var(--border);border-radius:8px;padding:6px 10px;outline:none;cursor:pointer}
  header select:focus{border-color:var(--accent)}
  header select{max-width:230px}
  .btn-ghost{transition:border-color .15s,color .15s}
  .btn-ghost:hover{border-color:var(--accent);color:var(--fg)}
  .btn-ghost:disabled{opacity:.45;cursor:default}
  .gh{color:var(--muted);font-size:13px;white-space:nowrap}

  /* kernel status pill */
  .kstat{display:inline-flex;align-items:center;gap:6px;font-size:12px;color:var(--muted);border:1px solid var(--border);border-radius:999px;padding:4px 11px;white-space:nowrap}
  .kdot{width:7px;height:7px;border-radius:50%;background:var(--muted);box-shadow:0 0 0 transparent;transition:background .2s,box-shadow .2s}
  .kstat.live .kdot{background:var(--ok);box-shadow:0 0 8px var(--ok)}
  .kstat.busy .kdot{background:var(--accent);box-shadow:0 0 8px var(--accent);animation:pulse 1s infinite}
  .kstat.err .kdot{background:var(--err);box-shadow:0 0 8px var(--err)}
  @keyframes pulse{50%{opacity:.35}}

  main{flex:1;min-height:0;overflow-y:auto;scroll-behavior:smooth}
  .thread{max-width:860px;margin:0 auto;padding:26px 18px 8px}

  .msg{display:flex;gap:13px;padding:14px 0;align-items:flex-start}
  .avatar{flex:none;width:30px;height:30px;border-radius:8px;display:grid;place-items:center;font-size:13px;font-weight:700;margin-top:2px}
  .msg.user .avatar{background:var(--user);color:var(--accent);border:1px solid var(--border)}
  .msg.assistant .avatar{background:linear-gradient(135deg,var(--accent),var(--accent2));color:#06101c}
  .bubble{flex:1;min-width:0}
  .role{font-size:12px;color:var(--muted);margin-bottom:3px;font-weight:600;letter-spacing:.2px}
  .msg.user .content{white-space:pre-wrap;word-break:break-word}

  /* flux-md renders into light DOM; theme its output here */
  flux-markdown{display:block;min-width:0}
  .content :first-child{margin-top:0}
  .content :last-child{margin-bottom:0}
  .content p{margin:.55em 0}
  .content h1,.content h2,.content h3,.content h4{margin:.9em 0 .4em;line-height:1.3}
  .content h1{font-size:1.45em}.content h2{font-size:1.28em}.content h3{font-size:1.13em}
  .content a{color:var(--accent)}
  .content code{font-family:var(--mono);font-size:.88em;background:var(--panel2);border:1px solid var(--border);border-radius:5px;padding:1px 5px}
  .content pre{background:#0a0d14;border:1px solid var(--border);border-radius:10px;padding:13px 15px;overflow:auto;margin:.6em 0}
  .content pre code{background:none;border:none;padding:0;font-size:.86em;line-height:1.5}
  .content table{border-collapse:collapse;margin:.6em 0;display:block;overflow:auto}
  .content th,.content td{border:1px solid var(--border);padding:6px 11px;text-align:left}
  .content th{background:var(--panel2)}
  .content blockquote{margin:.6em 0;padding:.1em 14px;border-left:3px solid var(--border);color:var(--muted)}
  .content ul,.content ol{padding-left:1.5em;margin:.5em 0}
  .content hr{border:none;border-top:1px solid var(--border);margin:1em 0}
  .content img{max-width:100%}

  .cursor::after{content:'▌';color:var(--accent);animation:blink 1s step-end infinite;margin-left:1px}
  @keyframes blink{50%{opacity:0}}

  /* run-result badges (used by notebook cells) */
  .badge{font-size:11px;padding:2px 8px;border-radius:999px;border:1px solid var(--border);color:var(--muted);font-family:var(--mono)}
  .badge.ok{color:var(--ok);border-color:#1c5b45}
  .badge.err{color:var(--err);border-color:#5b1f1f}
  .badge.warn{color:var(--warn);border-color:#5b4a1c}

  /* runnable notebook cells — flux-md code blocks made editable + runnable */
  .cell-ctrl{display:inline-flex;gap:6px;margin-left:auto}
  .flux-code-header{align-items:center}
  .cell-btn{font:inherit;font-size:11.5px;line-height:1;color:var(--fg);background:var(--panel2);border:1px solid var(--border);border-radius:7px;padding:5px 10px;cursor:pointer;white-space:nowrap;transition:border-color .15s,opacity .15s}
  .cell-btn:hover{border-color:var(--accent)}
  .cell-btn.run{color:#06101c;background:linear-gradient(135deg,var(--accent),var(--accent2));border:none;font-weight:600}
  .cell-btn:disabled{opacity:.45;cursor:default}
  .cell-src{display:block;width:100%;resize:vertical;border:none;outline:none;background:#0a0d14;color:#cfd6e4;font:12.5px/1.55 var(--mono);padding:12px 14px;white-space:pre;overflow:auto;tab-size:4;min-height:2.2em}
  .cell-src:focus{box-shadow:inset 0 0 0 1px var(--accent)}
  .cell-out{margin:0;border-top:1px solid var(--border);padding:11px 14px;overflow:auto;font:12.5px/1.5 var(--mono);white-space:pre-wrap;word-break:break-word;max-height:360px;background:var(--panel)}
  .cell-out.running{color:var(--accent)}
  .cell-out .label{display:block;font-family:system-ui,sans-serif;font-size:11px;color:var(--muted);letter-spacing:.4px;text-transform:uppercase;margin:0 0 4px}
  .cell-out .label.err{color:var(--err)}
  .cell-out .stderr{color:var(--err)}
  .cell-badges{display:flex;gap:6px;flex-wrap:wrap;margin-top:8px}

  /* header auto-run toggle */
  .toggle{display:inline-flex;align-items:center;gap:6px;font-size:12.5px;color:var(--muted);cursor:pointer;user-select:none;white-space:nowrap}
  .toggle input{accent-color:var(--accent);width:15px;height:15px;cursor:pointer;margin:0}

  .sys-note{max-width:860px;margin:6px auto;padding:9px 14px;color:var(--warn);font-size:13px;border:1px solid #5b4a1c;border-radius:10px;background:rgba(255,209,102,.06)}
  .sys-note.err{color:var(--err);border-color:#5b1f1f;background:rgba(255,107,107,.06)}

  /* persistent, non-blocking status line while all kernel slots are busy (429) */
  .kernel-busy-banner{max-width:860px;margin:6px auto;padding:9px 14px;color:var(--accent);font-size:13px;border:1px solid var(--border);border-radius:10px;background:rgba(93,184,255,.07)}

  .welcome{max-width:720px;margin:7vh auto 0;text-align:center;padding:0 18px}
  .welcome h2{font-size:24px;margin:0 0 8px;background:linear-gradient(90deg,var(--accent),var(--accent2));-webkit-background-clip:text;background-clip:text;color:transparent}
  .welcome p{color:var(--muted);margin:0 0 22px}
  .chips{display:flex;gap:10px;flex-wrap:wrap;justify-content:center}
  .chip{border:1px solid var(--border);background:var(--panel);border-radius:11px;padding:11px 14px;text-align:left;cursor:pointer;font-size:13px;color:var(--fg);transition:border-color .15s,transform .1s;max-width:235px}
  .chip:hover{border-color:var(--accent);transform:translateY(-1px)}
  .chip b{display:block;color:var(--accent);font-size:12px;margin-bottom:2px}

  /* composer */
  .composer-wrap{border-top:1px solid var(--border);background:linear-gradient(180deg,#0b0e14,#0d1119)}
  .composer{max-width:860px;margin:0 auto;padding:13px 18px 16px}
  .inputrow{display:flex;align-items:flex-end;gap:10px;background:var(--panel);border:1px solid var(--border);border-radius:14px;padding:8px 8px 8px 14px;transition:border-color .15s}
  .inputrow:focus-within{border-color:var(--accent)}
  #prompt{flex:1;resize:none;border:none;outline:none;background:none;color:var(--fg);font:15px/1.5 inherit;max-height:200px;padding:6px 0}
  .send{flex:none;width:38px;height:38px;border-radius:10px;border:none;cursor:pointer;display:grid;place-items:center;background:linear-gradient(135deg,var(--accent),var(--accent2));color:#06101c;font-size:17px;transition:opacity .15s}
  .send:disabled{opacity:.4;cursor:default}
  .send.stop{background:var(--err);color:#1a0606}
  .foot{display:flex;align-items:center;gap:8px;justify-content:center;margin-top:9px;color:var(--muted);font-size:11.5px;flex-wrap:wrap}
  .foot kbd{font:11px var(--mono);background:var(--panel2);border:1px solid var(--border);border-bottom-width:2px;border-radius:5px;padding:1px 5px}
  .dot{width:6px;height:6px;border-radius:50%;background:var(--ok);display:inline-block;box-shadow:0 0 7px var(--ok)}

  /* icon-only header button (gear) */
  .btn-ghost.icon-btn{padding:6px 9px;font-size:14px;line-height:1}

  /* settings popover (AI backend config) */
  .settings-panel{position:absolute;right:14px;top:52px;z-index:40;width:min(340px,calc(100vw - 24px));background:var(--panel2);border:1px solid var(--border);border-radius:12px;padding:15px 16px 13px;box-shadow:0 14px 40px rgba(0,0,0,.5)}
  .settings-panel[hidden]{display:none}
  .settings-panel h3{margin:0 0 12px;font-size:14px;letter-spacing:.2px}
  .settings-field{display:block;margin:0 0 11px}
  .settings-field>span{display:block;font-size:12px;color:var(--muted);margin:0 0 4px}
  .settings-field>span em{font-style:normal;opacity:.75}
  .settings-field input{width:100%;font:inherit;font-size:13px;color:var(--fg);background:var(--panel);border:1px solid var(--border);border-radius:8px;padding:7px 10px;outline:none}
  .settings-field input:focus{border-color:var(--accent)}
  .settings-actions{display:flex;align-items:center;gap:8px;margin-top:14px}
  .settings-actions .spacer{flex:1}
  .settings-note{margin:11px 0 0;font-size:11.5px;line-height:1.5;color:var(--muted)}
  .settings-note code{font-family:var(--mono);font-size:.92em;background:var(--panel);border:1px solid var(--border);border-radius:4px;padding:0 4px}
  /* detected-mode row (read-only) */
  .settings-mode{display:flex;align-items:center;justify-content:space-between;gap:10px;margin:0 0 12px}
  .settings-mode-label{font-size:12px;color:var(--muted)}
  .mode-indicator{font-size:12px;font-weight:600;padding:3px 9px;border-radius:999px;border:1px solid var(--border);white-space:nowrap}
  .mode-indicator.server{color:var(--ok);border-color:#1c5b45}
  .mode-indicator.direct{color:var(--muted)}
  /* auto-run checkbox row */
  .settings-check{display:flex;align-items:center;gap:8px;margin:0 0 12px;font-size:13px;cursor:pointer;user-select:none}
  .settings-check input{accent-color:var(--accent);width:15px;height:15px;cursor:pointer;margin:0}
  .settings-check em{font-style:normal;color:var(--muted);opacity:.85}
  /* section divider label */
  .settings-section{font-size:11px;color:var(--muted);text-transform:uppercase;letter-spacing:.4px;border-top:1px solid var(--border);padding-top:11px;margin:2px 0 11px}

  /* copy-message button on assistant bubbles */
  .msg-actions{display:flex;gap:8px;margin-top:6px}
  .msg-copy{font:inherit;font-size:11.5px;line-height:1;color:var(--muted);background:none;border:1px solid var(--border);border-radius:7px;padding:4px 9px;cursor:pointer;transition:border-color .15s,color .15s}
  .msg-copy:hover{border-color:var(--accent);color:var(--fg)}

  /* "Continue" affordance (iteration cap, either mode) */
  .continue-wrap{max-width:860px;margin:4px auto 10px;display:flex;justify-content:center}
  .continue-btn{font:inherit;font-size:13px;color:var(--fg);background:var(--panel2);border:1px solid var(--border);border-radius:999px;padding:7px 16px;cursor:pointer;transition:border-color .15s,color .15s}
  .continue-btn:hover{border-color:var(--accent);color:var(--fg)}

  /* rich display artifacts under a cell's output */
  .cell-arts{margin-top:10px;display:flex;flex-direction:column;gap:10px}
  .art-fig{margin:0;position:relative;display:inline-block;max-width:100%}
  .art-img{display:block;max-width:100%;height:auto;border:1px solid var(--border);border-radius:8px;background:#fff}
  .art-dl{position:absolute;top:6px;right:6px;font:inherit;font-size:11px;line-height:1;color:var(--fg);background:rgba(11,14,20,.72);border:1px solid var(--border);border-radius:6px;padding:4px 8px;text-decoration:none;opacity:0;transition:opacity .15s}
  .art-fig:hover .art-dl,.art-dl:focus{opacity:1}
  .art-html{display:block;width:100%;height:220px;max-height:55vh;border:1px solid var(--border);border-radius:8px;background:#fff}
  .art-dropped{font-size:12px;color:var(--muted);border:1px dashed var(--border);border-radius:8px;padding:9px 12px;font-style:italic}

  /* ── composer attachments ── */
  .attach-btn{flex:none;width:34px;height:34px;align-self:flex-end;border-radius:9px;border:1px solid var(--border);background:var(--panel2);color:var(--muted);font-size:15px;cursor:pointer;display:grid;place-items:center;transition:border-color .15s,color .15s}
  .attach-btn:hover{border-color:var(--accent);color:var(--fg)}
  .attach-bar{display:flex;flex-wrap:wrap;gap:7px;margin:0 0 9px}
  .attach-bar[hidden]{display:none}
  .attach-chip{display:inline-flex;align-items:center;gap:7px;max-width:100%;font-size:12px;background:var(--panel2);border:1px solid var(--border);border-radius:9px;padding:5px 9px}
  .attach-chip.err{border-color:#5b1f1f}
  .attach-spin{font-size:12px;color:var(--accent);animation:spin 1s linear infinite;flex:none}
  .attach-spin.ok{color:var(--ok);animation:none}
  .attach-spin.err{color:var(--err);animation:none}
  @keyframes spin{to{transform:rotate(360deg)}}
  .attach-name{max-width:190px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
  .attach-size{color:var(--muted);flex:none}
  .attach-x{flex:none;border:none;background:none;color:var(--muted);cursor:pointer;font-size:12px;line-height:1;padding:0 1px;opacity:0;transition:opacity .15s,color .15s}
  .attach-chip:hover .attach-x{opacity:1}
  .attach-x:hover{color:var(--fg)}

  /* ── drag-and-drop hint ── */
  body.dragging::after{content:"Drop files to upload to /workspace";position:fixed;inset:0;z-index:60;display:grid;place-items:center;pointer-events:none;background:rgba(11,14,20,.72);border:2px dashed var(--accent);border-radius:10px;color:var(--fg);font-size:16px;font-weight:600}

  /* ── workspace files panel ── */
  .files-panel{position:absolute;right:14px;top:52px;z-index:40;width:min(380px,calc(100vw - 24px));max-height:min(70vh,560px);display:flex;flex-direction:column;background:var(--panel2);border:1px solid var(--border);border-radius:12px;padding:13px 14px 11px;box-shadow:0 14px 40px rgba(0,0,0,.5)}
  .files-panel[hidden]{display:none}
  .files-head{display:flex;align-items:center;flex-wrap:wrap;gap:8px;margin:0 0 10px}
  .files-head h3{margin:0;font-size:14px;letter-spacing:.2px}
  .files-head-spacer{flex:1}
  .icon-mini{border:1px solid var(--border);background:var(--panel);color:var(--muted);border-radius:7px;width:28px;height:28px;font-size:13px;cursor:pointer;display:grid;place-items:center;transition:border-color .15s,color .15s}
  .icon-mini:hover{border-color:var(--accent);color:var(--fg)}
  .files-dl-all{border:1px solid var(--border);background:var(--panel);color:var(--muted);border-radius:7px;height:28px;padding:0 10px;font:inherit;font-size:11.5px;line-height:1;white-space:nowrap;cursor:pointer;transition:border-color .15s,color .15s}
  .files-dl-all:hover:not(:disabled){border-color:var(--accent);color:var(--fg)}
  .files-dl-all:disabled{opacity:.45;cursor:default}
  .files-body{overflow-y:auto;flex:1;min-height:40px;display:flex;flex-direction:column;gap:4px}
  .files-empty{font-size:12.5px;line-height:1.5;color:var(--muted);padding:14px 4px;text-align:center}
  .file-row{display:flex;align-items:center;gap:10px;padding:6px 8px;border-radius:8px;border:1px solid transparent}
  .file-row:hover{border-color:var(--border);background:var(--panel)}
  .file-row.dir{opacity:.75}
  .file-info{flex:1;min-width:0;display:flex;flex-direction:column;gap:1px}
  .file-name{font-size:13px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
  .file-meta{font-size:11px;color:var(--muted)}
  .file-actions{flex:none;display:flex;gap:4px}
  .file-btn{border:1px solid var(--border);background:var(--panel2);color:var(--muted);border-radius:6px;width:28px;height:28px;font-size:13px;cursor:pointer;display:grid;place-items:center;transition:border-color .15s,color .15s}
  .file-btn:hover{border-color:var(--accent);color:var(--fg)}
  .file-btn.danger:hover{border-color:var(--err);color:var(--err)}
  .file-btn:disabled{opacity:.45;cursor:default}
  .file-preview{padding:6px 8px 2px}
  .file-preview img{display:block;max-width:100%;max-height:320px;height:auto;border:1px solid var(--border);border-radius:8px;background:#fff}
  .files-note{margin:9px 0 0;font-size:11px;line-height:1.5;color:var(--muted)}
  .files-note code{font-family:var(--mono);background:var(--panel);border:1px solid var(--border);border-radius:4px;padding:0 3px}

  /* header stays usable on narrow screens */
  @media (max-width:640px){
    header{gap:8px;padding:10px 12px}
    header .tag{display:none}
    .gh{display:none}
    .settings-panel,.files-panel{right:8px;top:auto}
  }