/* Design tokens */
:root {
  --bg: #f6f7fb;
  --fg: #141922;
  --muted: #667085;
  --border: #e5e7eb;
  --primary: #6c4ef6;
  --primary-fg: #ffffff;
  --accent: #0682f4;
  --danger: #e11d48;
  --radius: 8px;
  --shadow-1: 0 1px 2px rgba(0,0,0,.06);
  --shadow-2: 0 8px 24px rgba(0,0,0,.08);
}

[data-theme="dark"] {
  --bg: #0f1220;
  --fg: #f3f4f6;
  --muted: #a1a1aa;
  --border: #1f2436;
  --primary: #8b7cf9;
  --primary-fg: #0f1220;
  --accent: #47a7ff;
  --danger: #fb7185;
}

* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--fg);
  font: 14px/1.45 Inter, ui-sans-serif, system-ui, -apple-system, Segoe UI, Roboto, Ubuntu, Cantarell, Noto Sans, Helvetica Neue, Arial, "Apple Color Emoji", "Segoe UI Emoji";
}

.topbar {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; gap: 16px;
  padding: 10px 16px; border-bottom: 1px solid var(--border);
  background: var(--bg); box-shadow: var(--shadow-1);
}
.brand { font-weight: 700; letter-spacing: .2px; }
.actions { display: flex; gap: 8px; align-items: center; flex: 1; }
.input { padding: 8px 10px; border: 1px solid var(--border); border-radius: var(--radius); background: transparent; color: var(--fg); width: 280px; }
.btn { padding: 8px 12px; border: 1px solid var(--border); border-radius: var(--radius); background: transparent; color: var(--fg); cursor: pointer; }
.btn.primary { background: var(--primary); border-color: var(--primary); color: var(--primary-fg); }
.btn:focus, .input:focus, textarea:focus { outline: 2px solid var(--accent); outline-offset: 2px; }

.layout { display: grid; grid-template-columns: 280px 1fr 360px; height: calc(100vh - 56px); }
.sidebar { border-right: 1px solid var(--border); overflow: auto; }
.sidebar-header, .assistant-header { padding: 8px 12px; font-weight: 600; border-bottom: 1px solid var(--border); }
.tree { list-style: none; padding: 8px; margin: 0; }
.tree li { padding: 4px 6px; margin: 2px 0; border-radius: 6px; }
.tree li[role="treeitem"]:hover { background: rgba(0,0,0,.04); }

.editor { display: grid; grid-template-rows: auto 1fr; border-right: 1px solid var(--border); }
.tabs { display: flex; gap: 6px; padding: 6px; border-bottom: 1px solid var(--border); overflow: auto; }
.tabs .tab { padding: 6px 10px; border: 1px solid var(--border); border-radius: 999px; cursor: pointer; background: transparent; }
.codepane { margin: 0; padding: 12px; overflow: auto; height: 100%; }

.assistant { display: grid; grid-template-rows: auto 1fr auto; }
.chat { padding: 12px; overflow: auto; }
.message { background: rgba(0,0,0,.04); padding: 8px 10px; border-radius: 10px; margin: 6px 0; }
.message.user { background: rgba(6,130,244,.10); }
.message.assistant { background: rgba(108,78,246,.10); }
.composer { display: grid; grid-template-columns: 1fr auto; gap: 8px; padding: 8px; border-top: 1px solid var(--border); }
.composer textarea { width: 100%; padding: 8px; border: 1px solid var(--border); border-radius: var(--radius); resize: vertical; }
.checkbox { align-self: center; color: var(--muted); }

.tray { border-top: 1px solid var(--border); height: 220px; display: grid; grid-template-rows: auto 1fr; }
.tray-tabs { display: flex; gap: 8px; padding: 8px; border-bottom: 1px solid var(--border); }
.tab { padding: 6px 10px; border: 1px solid var(--border); border-radius: 999px; background: transparent; cursor: pointer; }
.tab.active { background: var(--primary); color: var(--primary-fg); border-color: var(--primary); }
.panel { display: none; padding: 8px; overflow: auto; }
.panel.active { display: block; }

@media (max-width: 1200px) {
  .layout { grid-template-columns: 240px 1fr; }
  .assistant { display: none; }
}