/* ========================================
   Chat Interface - GPT/Gemini Inspired
   ======================================== */

.chat-layout {
  display: flex;
  height: 100vh;
  width: 100vw;
  overflow: hidden;
  background: var(--color-bg-primary);
  color: var(--color-text-primary);
  font-family: var(--font-sans);
}

/* --- Sidebar --- */
.chat-sidebar {
  width: var(--sidebar-width);
  min-width: var(--sidebar-width);
  background: var(--color-bg-sidebar);
  border-right: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  height: 100vh;
  position: relative;
  z-index: 10;
  transition: transform var(--transition-slow);
}

.chat-sidebar-header {
  padding: var(--spacing-4) var(--spacing-4) var(--spacing-2);
  border-bottom: 1px solid var(--color-border);
  flex-shrink: 0;
}

.chat-sidebar-brand {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  padding: var(--spacing-2) var(--spacing-2);
  margin-bottom: var(--spacing-2);
}

.chat-sidebar-logo {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-lg);
  background: linear-gradient(135deg, var(--color-gradient-start), var(--color-gradient-end));
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}
.chat-sidebar-logo svg { width: 18px; height: 18px; fill: white; }

.chat-sidebar-name {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  line-height: var(--line-height-tight);
}

.chat-sidebar-new-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-2);
  width: 100%;
  padding: 10px;
  margin: var(--spacing-2) 0;
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  color: var(--color-text-primary);
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-family: inherit;
}
.chat-sidebar-new-btn:hover {
  background: var(--color-bg-hover);
  border-color: var(--color-border-heavy);
}

.chat-sidebar-body {
  flex: 1;
  overflow-y: auto;
  padding: var(--spacing-2);
}
.chat-sidebar-body::-webkit-scrollbar { width: 4px; }
.chat-sidebar-body::-webkit-scrollbar-thumb { background: var(--color-border); border-radius: var(--radius-full); }
.chat-sidebar-body::-webkit-scrollbar-track { background: transparent; }

.chat-history-item {
  padding: var(--spacing-3) var(--spacing-3);
  margin-bottom: 2px;
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  position: relative;
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  border: none;
  background: none;
  width: 100%;
  text-align: left;
  font-family: inherit;
}
.chat-history-item:hover {
  background: var(--color-bg-hover);
  color: var(--color-text-primary);
}
.chat-history-item.active {
  background: var(--color-accent-soft);
  color: var(--color-accent);
}
.chat-history-item .truncate { flex: 1; }
.chat-history-item .delete-btn {
  opacity: 0;
  transition: opacity var(--transition-fast);
  color: var(--color-text-tertiary);
  cursor: pointer;
  padding: 2px;
  border-radius: var(--radius-sm);
}
.chat-history-item:hover .delete-btn { opacity: 0.6; }
.chat-history-item .delete-btn:hover { opacity: 1; color: var(--color-danger); }

.chat-sidebar-footer {
  padding: var(--spacing-3) var(--spacing-4);
  border-top: 1px solid var(--color-border);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
}

.chat-user-info {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  flex: 1;
  min-width: 0;
  cursor: pointer;
  padding: var(--spacing-1) var(--spacing-2);
  border-radius: var(--radius-lg);
  transition: background var(--transition-fast);
}
.chat-user-info:hover { background: var(--color-bg-hover); }

.chat-user-avatar {
  width: 28px;
  height: 28px;
  border-radius: var(--radius-full);
  background: var(--color-bg-tertiary);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-secondary);
}
.chat-user-avatar img { width: 100%; height: 100%; border-radius: var(--radius-full); object-fit: cover; }

.chat-user-name {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-primary);
  line-height: var(--line-height-tight);
}

/* --- Main Content --- */
.chat-main {
  flex: 1;
  display: flex;
  flex-direction: column;
  height: 100vh;
  min-width: 0;
  background: var(--color-bg-chat);
}

.chat-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-3) var(--spacing-6);
  border-bottom: 1px solid var(--color-border);
  flex-shrink: 0;
  min-height: 56px;
}

.chat-header-left {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  min-width: 0;
}

.chat-header-title {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  line-height: var(--line-height-tight);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.chat-header-subtitle {
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
}

.chat-header-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-1);
}

.chat-header-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: var(--radius-lg);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: none;
  background: none;
}
.chat-header-btn:hover {
  background: var(--color-bg-hover);
  color: var(--color-text-primary);
}
.chat-header-btn svg { width: 18px; height: 18px; stroke: currentColor; fill: none; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

/* --- Messages --- */
.chat-messages {
  flex: 1;
  overflow-y: auto;
  padding: var(--spacing-4) 0;
  scroll-behavior: smooth;
}
.chat-messages::-webkit-scrollbar { width: 6px; }
.chat-messages::-webkit-scrollbar-thumb { background: var(--color-border); border-radius: var(--radius-full); }
.chat-messages::-webkit-scrollbar-track { background: transparent; }

.chat-messages-inner {
  max-width: var(--max-content-width);
  margin: 0 auto;
  padding: 0 var(--spacing-6);
}

.message {
  display: flex;
  gap: var(--spacing-3);
  margin-bottom: var(--spacing-6);
  animation: fadeInUp var(--transition-slow) ease;
  padding: var(--spacing-4) 0;
}

.message-avatar {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-full);
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-semibold);
  margin-top: 4px;
}
.message-avatar.user {
  background: linear-gradient(135deg, var(--color-gradient-start), var(--color-gradient-end));
  color: white;
  order: 1;
}
.message-avatar.assistant {
  background: var(--color-bg-tertiary);
  color: var(--color-text-secondary);
}
.message-avatar svg { width: 18px; height: 18px; fill: currentColor; }

.message-body {
  flex: 1;
  min-width: 0;
}
.message-body.user { order: 0; }

.message-content {
  font-size: var(--font-size-lg);
  line-height: var(--line-height-relaxed);
  color: var(--color-text-primary);
  word-wrap: break-word;
}
.message-content.user {
  color: var(--color-text-primary);
}

.message-actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  margin-top: var(--spacing-2);
  opacity: 0;
  transition: opacity var(--transition-fast);
}
.message:hover .message-actions { opacity: 1; }

.message-action-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  border-radius: var(--radius-md);
  color: var(--color-text-tertiary);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: none;
  background: none;
}
.message-action-btn:hover {
  background: var(--color-bg-hover);
  color: var(--color-text-primary);
}
.message-action-btn svg { width: 14px; height: 14px; stroke: currentColor; fill: none; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

.message-time {
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
}

/* Welcome Screen */
.welcome-screen {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  text-align: center;
  padding: var(--spacing-8);
  animation: fadeIn 500ms ease;
}

.welcome-icon {
  width: 64px;
  height: 64px;
  border-radius: var(--radius-2xl);
  background: linear-gradient(135deg, var(--color-gradient-start), var(--color-gradient-end));
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--spacing-6);
  box-shadow: 0 8px 24px rgba(16, 163, 127, 0.3);
}
.welcome-icon svg { width: 32px; height: 32px; fill: white; }

.welcome-title {
  font-size: var(--font-size-4xl);
  font-weight: var(--font-weight-bold);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-3);
  letter-spacing: var(--letter-spacing-tight);
}

.welcome-desc {
  font-size: var(--font-size-md);
  color: var(--color-text-secondary);
  max-width: 480px;
  line-height: var(--line-height-relaxed);
  margin-bottom: var(--spacing-8);
}

.welcome-suggestions {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-3);
  max-width: 560px;
  width: 100%;
}

.welcome-suggestion {
  padding: var(--spacing-4);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-2xl);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-align: left;
  background: var(--color-surface);
}
.welcome-suggestion:hover {
  border-color: var(--color-border-heavy);
  background: var(--color-bg-hover);
  transform: translateY(-1px);
}
.welcome-suggestion-title {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-1);
}
.welcome-suggestion-desc {
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
  line-height: var(--line-height-normal);
}

/* --- Input Panel --- */
.chat-input-panel {
  border-top: 1px solid var(--color-border);
  padding: var(--spacing-3) var(--spacing-6) var(--spacing-4);
  flex-shrink: 0;
  background: var(--color-bg-chat);
}

.chat-input-toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-2);
  margin-bottom: var(--spacing-2);
}

.chat-tool-btn {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 4px 12px;
  font-size: var(--font-size-xs);
  color: var(--color-text-secondary);
  background: transparent;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-fast);
  font-family: inherit;
}
.chat-tool-btn:hover {
  background: var(--color-bg-hover);
  color: var(--color-text-primary);
  border-color: var(--color-border-heavy);
}
.chat-tool-btn.active {
  background: var(--color-accent-soft);
  color: var(--color-accent);
  border-color: transparent;
}
.chat-tool-btn svg { width: 14px; height: 14px; stroke: currentColor; fill: none; stroke-width: 2; }

.chat-input-wrapper {
  display: flex;
  align-items: flex-end;
  gap: var(--spacing-2);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-2xl);
  padding: var(--spacing-2) var(--spacing-2) var(--spacing-2) var(--spacing-4);
  transition: all var(--transition-fast);
}
.chat-input-wrapper:focus-within {
  border-color: var(--color-border-focus);
  box-shadow: var(--shadow-glow);
}

.chat-input {
  flex: 1;
  border: none;
  outline: none;
  background: transparent;
  font-size: var(--font-size-md);
  color: var(--color-text-primary);
  resize: none;
  padding: 6px 0;
  max-height: 120px;
  line-height: var(--line-height-normal);
  font-family: inherit;
}
.chat-input::placeholder { color: var(--color-text-placeholder); }

.chat-input-actions {
  display: flex;
  align-items: center;
  gap: 2px;
  flex-shrink: 0;
}

.chat-input-action {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: var(--radius-lg);
  color: var(--color-text-tertiary);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: none;
  background: none;
}
.chat-input-action:hover {
  background: var(--color-bg-hover);
  color: var(--color-text-primary);
}
.chat-input-action svg { width: 18px; height: 18px; stroke: currentColor; fill: none; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

.chat-send-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  border-radius: var(--radius-lg);
  background: var(--color-accent);
  color: white;
  cursor: pointer;
  transition: all var(--transition-fast);
  border: none;
}
.chat-send-btn:hover:not(:disabled) {
  background: var(--color-accent-hover);
  transform: scale(1.05);
}
.chat-send-btn:active:not(:disabled) { transform: scale(0.95); }
.chat-send-btn:disabled { opacity: 0.4; cursor: not-allowed; }
.chat-send-btn svg { width: 18px; height: 18px; stroke: currentColor; fill: none; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }

/* --- Model Selector --- */
.model-selector {
  position: absolute;
  bottom: calc(100% + 8px);
  left: var(--spacing-6);
  right: var(--spacing-6);
  background: var(--color-surface-modal);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-2xl);
  box-shadow: var(--shadow-2xl);
  max-height: 320px;
  overflow-y: auto;
  z-index: 100;
  display: none;
  animation: fadeInUp var(--transition-fast) ease;
}
.model-selector.show { display: block; }
.model-selector::-webkit-scrollbar { width: 4px; }
.model-selector::-webkit-scrollbar-thumb { background: var(--color-border); border-radius: var(--radius-full); }

.model-group-title {
  padding: var(--spacing-3) var(--spacing-4) var(--spacing-1);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-tertiary);
  text-transform: uppercase;
  letter-spacing: var(--letter-spacing-wide);
}

.model-option {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: var(--spacing-3) var(--spacing-4);
  border: none;
  background: none;
  cursor: pointer;
  transition: background var(--transition-fast);
  font-family: inherit;
  text-align: left;
}
.model-option:hover { background: var(--color-bg-hover); }
.model-option.selected { background: var(--color-accent-soft); }

.model-option-name {
  font-size: var(--font-size-sm);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-primary);
}
.model-option-price {
  font-size: var(--font-size-xs);
  color: var(--color-text-tertiary);
}

/* Thinking indicator */
.thinking-indicator {
  display: flex;
  align-items: center;
  gap: var(--spacing-3);
  padding: var(--spacing-4) 0;
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}
.thinking-dots {
  display: flex;
  gap: 4px;
}
.thinking-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--color-text-tertiary);
  animation: pulse 1.4s infinite;
}
.thinking-dot:nth-child(2) { animation-delay: 0.2s; }
.thinking-dot:nth-child(3) { animation-delay: 0.4s; }

/* --- Toast in chat --- */
.chat-toast {
  position: fixed;
  bottom: 100px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1000;
  padding: 8px 20px;
  background: var(--color-text-primary);
  color: var(--color-text-inverse);
  border-radius: var(--radius-full);
  font-size: var(--font-size-sm);
  box-shadow: var(--shadow-lg);
  animation: fadeInUp var(--transition-fast) ease;
  pointer-events: none;
}

/* --- Mobile --- */
.mobile-menu-btn {
  display: none;
}

@media (max-width: 768px) {
  .chat-layout { position: relative; }

  .chat-sidebar {
    position: fixed;
    left: 0;
    top: 0;
    transform: translateX(-100%);
    z-index: 100;
    box-shadow: var(--shadow-2xl);
    width: 85vw;
    max-width: 320px;
  }
  .chat-sidebar.open {
    transform: translateX(0);
  }

  .chat-sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    z-index: 99;
  }
  .chat-sidebar-overlay.show { display: block; }

  .mobile-menu-btn { display: flex; }

  .chat-messages-inner { padding: 0 var(--spacing-4); }
  .chat-input-panel { padding: var(--spacing-2) var(--spacing-4) var(--spacing-4); }
  .chat-header { padding: var(--spacing-2) var(--spacing-4); }

  .message { gap: var(--spacing-2); padding: var(--spacing-2) 0; }
  .message-content { font-size: var(--font-size-md); }

  .welcome-suggestions { grid-template-columns: 1fr; }
  .welcome-title { font-size: var(--font-size-3xl); }

  .chat-input-wrapper { border-radius: var(--radius-xl); padding: var(--spacing-1) var(--spacing-1) var(--spacing-1) var(--spacing-3); }
}

@media (max-width: 480px) {
  .chat-header-subtitle { display: none; }
  .welcome-icon { width: 48px; height: 48px; }
  .welcome-icon svg { width: 24px; height: 24px; }
  .welcome-desc { font-size: var(--font-size-sm); }
}