:root {
  color-scheme: light dark;
  --bg: #f6f7fb;
  --panel: rgba(255, 255, 255, 0.82);
  --panel-solid: #ffffff;
  --text: #111827;
  --muted: #6b7280;
  --border: rgba(17, 24, 39, 0.10);
  --accent: #2563eb;
  --accent-strong: #1d4ed8;
  --assistant: #ffffff;
  --user: #2563eb;
  --user-text: #ffffff;
  --space-accent-text: var(--user-text);
  --shadow: 0 18px 48px rgba(15, 23, 42, 0.12);
  --radius: 20px;
  --sidebar-w: 320px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0f19;
    --panel: rgba(15, 23, 42, 0.76);
    --panel-solid: #111827;
    --text: #f9fafb;
    --muted: #9ca3af;
    --border: rgba(255, 255, 255, 0.11);
    --accent: #60a5fa;
    --accent-strong: #3b82f6;
    --assistant: #111827;
    --user: #2563eb;
    --user-text: #ffffff;
    --space-accent-text: var(--user-text);
    --shadow: 0 18px 48px rgba(0, 0, 0, 0.42);
  }
}

* { box-sizing: border-box; }
html, body { height: 100%; overflow: hidden; overscroll-behavior: none; }
html.chat-shell-lock, html.chat-shell-lock body {
  height: var(--app-height, 100dvh);
  max-height: var(--app-height, 100dvh);
  overflow: hidden;
}
html.chat-shell-lock {
  position: fixed;
  inset: 0;
  width: 100%;
}
body {
  margin: 0;
  font: 15px/1.45 -apple-system, BlinkMacSystemFont, "Segoe UI", Inter, Roboto, sans-serif;
  background:
    radial-gradient(circle at top left, rgba(96, 165, 250, 0.18), transparent 34rem),
    radial-gradient(circle at bottom right, rgba(168, 85, 247, 0.13), transparent 30rem),
    var(--bg);
  color: var(--text);
}
body.chat-shell-lock,
body.chat-authenticated {
  position: fixed;
  inset: 0;
  width: 100%;
  max-width: 100%;
  height: var(--app-height, 100dvh);
  max-height: var(--app-height, 100dvh);
  overflow: hidden;
  overscroll-behavior: none;
  touch-action: manipulation;
}

button, input, textarea { font: inherit; }
button { cursor: pointer; }
button:disabled { cursor: not-allowed; opacity: 0.55; }

.app {
  display: grid;
  grid-template-columns: 320px 1fr;
  width: 100%;
  height: var(--app-height, 100dvh);
  overflow: hidden;
  isolation: isolate;
  transition: grid-template-columns .18s ease;
}
.app.sidebar-collapsed { grid-template-columns: 0 1fr; }
.app.sidebar-collapsed .sidebar { padding-inline: 0; border-right: 0; overflow: hidden; }
.sidebar {
  padding: max(18px, env(safe-area-inset-top)) 16px max(18px, env(safe-area-inset-bottom));
  border-right: 1px solid var(--border);
  background: var(--panel);
  backdrop-filter: blur(24px);
  overflow-y: auto;
  overscroll-behavior: contain;
  -webkit-overflow-scrolling: touch;
  z-index: 5;
}

@media (hover: hover) and (pointer: fine) {
  .sidebar {
    scrollbar-width: thin;
    scrollbar-color: transparent transparent;
    scrollbar-gutter: stable;
  }
  .sidebar:hover {
    scrollbar-color: color-mix(in srgb, var(--muted) 42%, transparent) transparent;
  }
  .sidebar::-webkit-scrollbar {
    width: 8px;
  }
  .sidebar::-webkit-scrollbar-thumb {
    background: transparent;
    border-radius: 999px;
  }
  .sidebar:hover::-webkit-scrollbar-thumb {
    background: color-mix(in srgb, var(--muted) 42%, transparent);
  }
}

.brand { display: flex; align-items: center; gap: 12px; margin-bottom: 18px; }
.brand > div:nth-child(2) { min-width: 0; flex: 1; }
.sidebar-close { margin-left: auto; display: none; }
.sidebar-backdrop { display: none; }
.brand-mark {
  width: 40px; height: 40px; border-radius: 14px;
  display: grid; place-items: center;
  background: linear-gradient(135deg, #2563eb, #7c3aed);
  color: white; font-weight: 800;
}
.brand-title { font-weight: 750; letter-spacing: -0.02em; }
.brand-subtitle-row { display: flex; align-items: stretch; gap: 6px; min-height: 18px; }
.brand-subtitle { color: var(--muted); font-size: 12px; }
.cluster-indicator {
  width: 3px;
  min-height: 16px;
  border-radius: 999px;
  background: var(--muted);
  box-shadow: 0 0 0 1px color-mix(in srgb, var(--panel-solid) 74%, transparent);
}
.cluster-indicator.blue { background: #2563eb; }
.cluster-indicator.green { background: #22c55e; }
.cluster-indicator.hidden { display: none; }
.topbar-cluster-indicator { flex: 0 0 3px; align-self: stretch; min-height: 30px; margin-left: -5px; }

.field { display: grid; gap: 6px; margin: 12px 0; }
.field label, .section-title { color: var(--muted); font-size: 12px; font-weight: 650; text-transform: uppercase; letter-spacing: 0.06em; }
.field input {
  width: 100%; border: 1px solid var(--border); border-radius: 13px;
  padding: 10px 12px; color: var(--text); background: var(--panel-solid);
  outline: none;
}
.field input:focus, textarea:focus { border-color: color-mix(in srgb, var(--accent) 60%, var(--border)); }

.primary, .secondary {
  border: 0; border-radius: 14px; padding: 11px 13px; font-weight: 700;
}
.primary { background: var(--accent); color: white; }
.primary:hover { background: var(--accent-strong); }
.secondary { background: var(--panel-solid); color: var(--text); border: 1px solid var(--border); }