.assistant-layout {
  display: flex;
  height: calc(100vh - var(--nav-h));
  position: relative; z-index: 1;
}

.chat-sidebar {
  width: 280px;
  background: rgba(15, 13, 28, 0.9);
  border-right: 1px solid var(--border);
  display: flex; flex-direction: column;
  flex-shrink: 0;
}
.sidebar-header {
  padding: 16px;
  border-bottom: 1px solid var(--border);
}
.new-chat-btn {
  width: 100%;
  padding: 12px 16px;
  background: linear-gradient(135deg, #a855f7, #7c3aed);
  border: none; border-radius: 10px;
  color: #fff;
  font-family: var(--font); font-weight: 700; font-size: 0.88rem;
  cursor: pointer;
  display: flex; align-items: center; gap: 8px;
  justify-content: center;
  transition: box-shadow 0.3s, transform 0.2s;
}
.new-chat-btn:hover {
  box-shadow: 0 4px 20px var(--accent-glow);
  transform: translateY(-1px);
}
.chat-list {
  flex: 1; overflow-y: auto;
  padding: 8px;
  display: flex; flex-direction: column; gap: 2px;
}
.chat-list-item {
  padding: 12px 14px;
  border-radius: 10px;
  font-size: 0.85rem;
  color: var(--text-dim);
  cursor: pointer;
  transition: all 0.2s;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  display: flex; align-items: center; justify-content: space-between;
  gap: 8px;
}
.chat-list-item:hover { background: var(--accent-dim); color: var(--text); }
.chat-list-item.active { background: var(--accent-dim); color: var(--accent); }
.chat-list-item .chat-title { flex: 1; overflow: hidden; text-overflow: ellipsis; }
.chat-list-item .delete-chat {
  display: none;
  background: none; border: none;
  color: var(--text-dim); cursor: pointer;
  font-size: 0.9rem; padding: 2px 4px;
  flex-shrink: 0;
}
.chat-list-item:hover .delete-chat { display: block; }
.chat-list-item .delete-chat:hover { color: var(--error); }
.sidebar-login-hint {
  padding: 16px;
  border-top: 1px solid var(--border);
  font-size: 0.8rem;
  color: var(--text-dim);
  text-align: center;
}
.sidebar-login-hint button {
  background: none; border: none;
  color: var(--accent); cursor: pointer;
  font-family: var(--font); font-weight: 600;
  font-size: 0.8rem;
}
.sidebar-login-hint button:hover { text-decoration: underline; }

.chat-main {
  flex: 1;
  display: flex; flex-direction: column;
  min-width: 0;
}
.chat-messages-area {
  flex: 1; overflow-y: auto;
  padding: 24px;
  display: flex; flex-direction: column; gap: 16px;
}
.chat-welcome {
  flex: 1;
  display: flex; flex-direction: column;
  align-items: center; justify-content: center;
  gap: 12px;
  text-align: center;
  padding: 40px;
}
.chat-welcome img {
  height: 80px; opacity: 0.6;
}
.chat-welcome h2 {
  font-family: var(--font-head);
  font-size: 1.4rem; font-weight: 700;
  background: linear-gradient(135deg, #c084fc, #a855f7);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.chat-welcome p {
  color: var(--text-dim);
  font-size: 0.9rem;
  max-width: 440px;
}
.chat-welcome-prompts {
  display: flex; flex-wrap: wrap; gap: 8px;
  justify-content: center;
  margin-top: 8px;
}
.prompt-chip {
  padding: 8px 16px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--text-dim);
  font-family: var(--font); font-size: 0.82rem;
  cursor: pointer;
  transition: all 0.25s;
}
.prompt-chip:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-dim);
}

.chat-bubble {
  max-width: 720px;
  width: 100%;
  margin: 0 auto;
  display: flex; gap: 14px;
  animation: fadeUp 0.3s ease;
}
.chat-bubble.user { flex-direction: row-reverse; }
.bubble-avatar {
  width: 36px; height: 36px;
  border-radius: 50%;
  flex-shrink: 0;
  display: flex; align-items: center; justify-content: center;
  font-size: 0.9rem; font-weight: 700;
}
.chat-bubble.assistant .bubble-avatar {
  background: var(--accent-dim);
  border: 1px solid var(--border);
  color: var(--accent);
}
.chat-bubble.user .bubble-avatar {
  background: linear-gradient(135deg, #a855f7, #7c3aed);
  color: #fff;
}
.bubble-content {
  flex: 1;
  padding: 14px 18px;
  border-radius: 16px;
  font-size: 0.9rem;
  line-height: 1.6;
  min-width: 0;
}
.chat-bubble.user .bubble-content {
  background: linear-gradient(135deg, rgba(168,85,247,0.2), rgba(124,58,237,0.2));
  border: 1px solid rgba(168,85,247,0.3);
  border-top-right-radius: 4px;
}
.chat-bubble.assistant .bubble-content {
  background: var(--surface);
  border: 1px solid var(--border);
  border-top-left-radius: 4px;
}
.bubble-content code {
  background: rgba(168,85,247,0.15);
  padding: 1px 5px;
  border-radius: 4px;
  font-family: 'Courier New', monospace;
  font-size: 0.84rem;
}
.code-wrap {
  margin-top: 10px;
  border: 1px solid var(--border);
  border-radius: 10px;
  overflow: hidden;
}
.code-header {
  display: flex; align-items: center; justify-content: space-between;
  padding: 8px 14px;
  background: rgba(168,85,247,0.08);
  border-bottom: 1px solid var(--border);
}
.code-lang {
  font-size: 0.75rem; font-weight: 700;
  text-transform: uppercase;
  color: var(--accent);
  letter-spacing: 0.04em;
}
.code-actions {
  display: flex; gap: 6px;
}
.code-action-btn {
  font-family: var(--font); font-size: 0.72rem; font-weight: 600;
  padding: 4px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: rgba(10,10,18,0.5);
  color: var(--text-dim);
  cursor: pointer;
  transition: all 0.2s;
}
.code-action-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.code-body {
  background: #0c0a18;
  padding: 14px;
  overflow-x: auto;
  font-family: 'Courier New', monospace;
  font-size: 0.82rem;
  line-height: 1.5;
  color: #c4b5fd;
  white-space: pre;
  margin: 0;
  transition: max-height 0.3s ease, padding 0.3s ease, opacity 0.3s ease;
  max-height: 600px;
}
.code-body.collapsed {
  max-height: 0;
  padding: 0 14px;
  opacity: 0;
  overflow: hidden;
}

.bubble-content pre:not(.code-body) {
  background: #0c0a18;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 14px;
  margin-top: 10px;
  overflow-x: auto;
  font-family: 'Courier New', monospace;
  font-size: 0.82rem;
  line-height: 1.5;
  color: #c4b5fd;
}
.typing-indicator {
  color: var(--text-dim);
  font-size: 0.85rem;
  font-style: italic;
}

.chat-input-area {
  padding: 16px 24px 24px;
  border-top: 1px solid var(--border);
  background: rgba(10,10,18,0.6);
}
.chat-input-wrap {
  max-width: 720px;
  margin: 0 auto;
  display: flex; gap: 10px;
  align-items: flex-end;
}
.chat-input-wrap textarea {
  flex: 1;
  padding: 14px 18px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  color: var(--text);
  font-family: var(--font); font-size: 0.92rem;
  outline: none;
  resize: none;
  min-height: 48px;
  max-height: 200px;
  line-height: 1.5;
  transition: border-color 0.3s;
}
.chat-input-wrap textarea::placeholder { color: var(--text-dim); }
.chat-input-wrap textarea:focus { border-color: var(--accent); }
.send-btn {
  width: 48px; height: 48px;
  border-radius: 14px;
  background: linear-gradient(135deg, #a855f7, #7c3aed);
  border: none;
  color: #fff;
  cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  flex-shrink: 0;
  transition: transform 0.2s, box-shadow 0.3s;
}
.send-btn:hover {
  transform: scale(1.05);
  box-shadow: 0 4px 20px var(--accent-glow);
}
.send-btn:disabled {
  opacity: 0.4; cursor: not-allowed; transform: none; box-shadow: none;
}

.chat-messages-area::-webkit-scrollbar,
.chat-list::-webkit-scrollbar { width: 5px; }
.chat-messages-area::-webkit-scrollbar-track,
.chat-list::-webkit-scrollbar-track { background: transparent; }
.chat-messages-area::-webkit-scrollbar-thumb,
.chat-list::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }

.sidebar-toggle {
  display: none;
  position: absolute; top: 12px; left: 12px; z-index: 10;
  width: 36px; height: 36px;
  border-radius: 10px;
  background: var(--surface);
  border: 1px solid var(--border);
  color: var(--text);
  cursor: pointer;
  align-items: center; justify-content: center;
  font-size: 1.1rem;
}

.sidebar-bottom {
  margin-top: auto;
}
.settings-btn {
  width: calc(100% - 32px);
  margin: 0 16px 4px;
  padding: 10px 14px;
  border-radius: 10px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-dim);
  font-family: var(--font); font-size: 0.84rem; font-weight: 600;
  cursor: pointer;
  display: flex; align-items: center; gap: 8px;
  transition: all 0.2s;
}
.settings-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-dim);
}

.settings-overlay {
  display: none; position: fixed; inset: 0; z-index: 500;
  background: rgba(10,10,18,0.85);
  backdrop-filter: blur(8px);
  justify-content: center; align-items: center;
  padding: 20px;
}
.settings-overlay.open { display: flex; }
.settings-panel {
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 36px;
  max-width: 440px; width: 100%;
  position: relative;
  animation: fadeUp 0.3s ease;
}
.settings-form {
  display: flex; flex-direction: column; gap: 16px;
  margin-top: 8px;
}
.setting-group {
  display: flex; flex-direction: column; gap: 6px;
}
.setting-group label {
  font-size: 0.84rem; font-weight: 600;
  color: var(--text-dim);
}
.setting-group select,
.setting-group textarea {
  width: 100%;
  padding: 10px 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  color: var(--text);
  font-family: var(--font); font-size: 0.88rem;
  outline: none;
  transition: border-color 0.3s;
}
.setting-group select:focus,
.setting-group textarea:focus {
  border-color: var(--accent);
}
.setting-group select option {
  background: var(--bg2);
  color: var(--text);
}
.setting-group textarea {
  resize: vertical;
  min-height: 60px;
  line-height: 1.5;
}

@media (max-width: 768px) {
  .chat-sidebar {
    position: fixed;
    top: var(--nav-h); left: 0; bottom: 0;
    z-index: 50;
    transform: translateX(-100%);
    transition: transform 0.3s;
  }
  .chat-sidebar.open { transform: translateX(0); }
  .sidebar-toggle { display: flex; }
  .chat-messages-area { padding: 16px; padding-top: 52px; }
  .chat-input-area { padding: 12px 16px 16px; }
  .chat-bubble { gap: 10px; }
}