:root {
  color-scheme: dark;
  --bg: #0f0f12;
  --panel: #1a1a1f;
  --border: #2a2a32;
  --text: #ececf1;
  --muted: #8e8ea0;
  --accent: #10a37f;
  --user-bubble: #343541;
  --assistant-bubble: #1e1e24;
}

* {
  box-sizing: border-box;
}

html {
  height: 100%;
}

body.chat-shell {
  margin: 0;
  font-family: "Segoe UI", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  height: 100%;
  min-height: 100dvh;
  max-height: 100dvh;
  overflow: hidden;
  display: flex;
  flex-direction: column;
}

.chat-topbar {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.75rem 1.25rem;
  border-bottom: 1px solid var(--border);
  background: var(--panel);
}

.brand {
  font-weight: 600;
  letter-spacing: 0.02em;
}

.nav-links a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.9rem;
}

.nav-links a:hover {
  color: var(--accent);
}

.status {
  margin-left: auto;
  font-size: 0.85rem;
  color: var(--muted);
}

.chat-layout {
  flex: 1;
  display: grid;
  grid-template-columns: 260px minmax(0, 1fr);
  min-height: 0;
  overflow: hidden;
}

.chat-sidebar {
  border-right: 1px solid var(--border);
  padding: 1rem;
  background: #121214;
  display: flex;
  flex-direction: column;
  min-height: 0;
  overflow: hidden;
}

.chat-sidebar > *:not(.session-list) {
  flex-shrink: 0;
}

.sidectl {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  font-size: 0.8rem;
  color: var(--muted);
  margin-bottom: 0.75rem;
}

.sidectl input {
  padding: 0.45rem 0.5rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--panel);
  color: var(--text);
}

.btn {
  border: none;
  border-radius: 8px;
  padding: 0.55rem 0.9rem;
  cursor: pointer;
  font-size: 0.9rem;
}

.btn.primary {
  background: var(--accent);
  color: #063;
  width: 100%;
  font-weight: 600;
}

.btn.secondary {
  background: #3e3e4c;
  color: var(--text);
  width: 100%;
}

.btn:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

.hint {
  font-size: 0.75rem;
  color: var(--muted);
  line-height: 1.4;
  margin-top: 0.75rem;
}

.session-list {
  margin-top: 1rem;
  font-size: 0.8rem;
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  padding-right: 0.25rem;
}

.session-row {
  display: flex;
  align-items: stretch;
  gap: 0.35rem;
  border-bottom: 1px solid var(--border);
  padding: 0.25rem 0;
}

.session-row .session-item {
  flex: 1;
  min-width: 0;
  padding: 0.4rem 0.2rem;
  cursor: pointer;
  color: var(--muted);
  border: none;
  background: transparent;
  font: inherit;
  text-align: left;
  line-height: 1.35;
}

.session-row .session-item:hover {
  color: var(--text);
}

.session-row .session-item.active {
  color: var(--accent);
}

.btn-del {
  flex-shrink: 0;
  align-self: flex-start;
  padding: 0.2rem 0.45rem;
  font-size: 0.72rem;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  position: relative;
  z-index: 1;
}

.btn-del:hover {
  color: #f87171;
  border-color: #7f1d1d;
}

.chat-main {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 340px;
  min-height: 0;
  min-width: 0;
  overflow: hidden;
  background: var(--bg);
}

.chat-core {
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 0;
}

.editor-panel {
  border-left: 1px solid var(--border);
  background: #121217;
  padding: 0.9rem;
  display: flex;
  flex-direction: column;
  gap: 0.55rem;
  min-height: 0;
  overflow: auto;
}

.editor-panel h3 {
  margin: 0;
  font-size: 0.95rem;
}

.editor-hint {
  margin: 0;
  font-size: 0.75rem;
  color: var(--muted);
}

.editor-outline {
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #0f0f14;
  padding: 0.35rem;
  min-height: 120px;
  max-height: 220px;
  overflow: auto;
}

.outline-item {
  width: 100%;
  text-align: left;
  border: 1px solid transparent;
  background: transparent;
  color: var(--text);
  border-radius: 6px;
  padding: 0.35rem 0.45rem;
  cursor: pointer;
}

.outline-item small {
  display: block;
  color: var(--muted);
  margin-top: 0.15rem;
}

.outline-item:hover {
  background: #1a1b22;
}

.outline-item.active {
  border-color: #2d6457;
  background: #162724;
}

.editor-label {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  font-size: 0.76rem;
  color: var(--muted);
}

.editor-panel textarea {
  width: 100%;
  resize: vertical;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: #0c0d12;
  color: var(--text);
  padding: 0.55rem 0.6rem;
  font: inherit;
  min-height: 64px;
}

.editor-actions {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.45rem;
}

.editor-actions .btn {
  width: 100%;
  min-width: 0;
}

.selection-toolbar {
  position: fixed;
  z-index: 2000;
  transform: translate(-50%, calc(-100% - 6px));
  padding: 0.25rem;
  border-radius: 8px;
  background: #2a2a32;
  border: 1px solid var(--border);
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.45);
  pointer-events: auto;
}

.selection-toolbar.hidden {
  display: none;
}

.selection-toolbar-btn {
  display: block;
  width: 100%;
  white-space: nowrap;
  padding: 0.35rem 0.65rem;
  font-size: 0.8rem;
  border-radius: 6px;
  border: none;
  cursor: pointer;
  background: var(--accent);
  color: #063;
  font-weight: 600;
}

.selection-toolbar-btn:hover {
  filter: brightness(1.08);
}

.messages,
.messages .msg-body {
  user-select: text;
}

.messages {
  flex: 1;
  min-height: 0;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 1.25rem 1.5rem;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  scroll-behavior: smooth;
}

.msg {
  max-width: 900px;
  align-self: flex-start;
  border-radius: 12px;
  padding: 0.9rem 1rem;
  line-height: 1.55;
  font-size: 0.95rem;
}

.msg.user {
  align-self: flex-end;
  background: var(--user-bubble);
  border: 1px solid var(--border);
}

.msg.assistant {
  background: var(--assistant-bubble);
  border: 1px solid var(--border);
  width: 100%;
  max-width: 960px;
}

.msg.assistant h1,
.msg.assistant h2,
.msg.assistant h3 {
  margin-top: 0.75rem;
  margin-bottom: 0.5rem;
  font-weight: 600;
}

.msg.assistant code {
  background: #111;
  padding: 0.1rem 0.25rem;
  border-radius: 4px;
}

.meta {
  font-size: 0.72rem;
  color: var(--muted);
  margin-bottom: 0.35rem;
}

.composer {
  flex-shrink: 0;
  border-top: 1px solid var(--border);
  padding: 1rem 1.25rem calc(1.25rem + env(safe-area-inset-bottom, 0px));
  background: var(--panel);
}

#chatInput {
  width: 100%;
  resize: vertical;
  max-height: 200px;
  min-height: 72px;
  padding: 0.65rem 0.75rem;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: #0d0d10;
  color: var(--text);
  font: inherit;
}

.composer-actions {
  margin-top: 0.75rem;
}

.mode-btns {
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.mode-btns .btn {
  width: auto;
  flex: 1;
  min-width: 160px;
}

.tinyhint {
  font-size: 0.75rem;
  color: var(--muted);
  margin: 0.5rem 0 0;
}

.mention-wrap {
  margin-bottom: 0.5rem;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: #0d0d10;
  max-height: 180px;
  overflow: auto;
}

.mention-wrap.hidden {
  display: none;
}

.mention-title {
  font-size: 0.75rem;
  color: var(--muted);
  padding: 0.35rem 0.5rem;
  border-bottom: 1px solid var(--border);
}

.mention-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.mention-list li {
  padding: 0.4rem 0.6rem;
  cursor: pointer;
  font-size: 0.82rem;
  border-bottom: 1px solid #24242c;
}

.mention-list li:hover {
  background: #25252e;
}

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-bottom: 0.35rem;
}

.chip {
  font-size: 0.75rem;
  background: #2d2d38;
  padding: 0.2rem 0.5rem;
  border-radius: 999px;
  color: #c5c5d0;
}

.context-chips .chip-row {
  display: inline-flex;
  align-items: center;
  gap: 0.15rem;
  max-width: 100%;
}

.context-chips .chip-context {
  max-width: min(100%, 28rem);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.chip-remove {
  flex-shrink: 0;
  border: none;
  background: transparent;
  color: var(--muted);
  font-size: 1rem;
  line-height: 1;
  cursor: pointer;
  padding: 0.1rem 0.35rem;
  border-radius: 4px;
}

.chip-remove:hover {
  color: var(--text);
  background: #2a2a32;
}

@media (max-width: 900px) {
  .chat-layout {
    grid-template-columns: 1fr;
    grid-template-rows: minmax(auto, min(38vh, 240px)) minmax(0, 1fr);
  }
  .chat-sidebar {
    border-right: none;
    border-bottom: 1px solid var(--border);
    flex-shrink: 0;
    max-height: min(38vh, 240px);
  }
  .chat-main {
    grid-template-columns: 1fr;
    grid-template-rows: minmax(0, 1fr) minmax(auto, 42vh);
  }
  .editor-panel {
    border-left: none;
    border-top: 1px solid var(--border);
  }
  .editor-actions {
    grid-template-columns: 1fr;
  }
}