/* ===================================
   ElderCare Companion - Modern Premium Design
   靈感來源：Gemini AI、現代化歐美高檔網頁設計
   =================================== */

:root {
  /* === 字體大小基準 - 可動態調整 === */
  --base-font-size: 24px; /* 預設中等大小，可通過 JavaScript 調整 */

  /* === 配色方案 - 預設使用深色主題 === */
  /* 主色調 - 深邃優雅 */
  --color-bg-primary: #0A0A0F;
  --color-bg-secondary: #141419;
  --color-bg-tertiary: #1E1E24;
  --color-bg-elevated: #28282F;

  /* 文字顏色 - 高對比度 */
  --color-text-primary: #E8EAED;
  --color-text-secondary: #BDC1C6;
  --color-text-tertiary: #9AA0A6;
  --color-text-disabled: #5F6368;

  /* 強調色 - 精緻科技感藍色（Apple 啟發） */
  --color-accent-primary: #0A84FF;
  --color-accent-secondary: #0071E3;
  --color-accent-hover: #409CFF;

  /* 漸層色 - 精緻優雅（Apple & SpaceX 啟發） */
  --gradient-primary: linear-gradient(135deg, #0A84FF 0%, #0066CC 100%);
  --gradient-secondary: linear-gradient(135deg, #0A84FF 0%, #0071E3 100%);
  --gradient-accent: linear-gradient(135deg, #FF375F 0%, #FF2D55 100%);
  --gradient-success: linear-gradient(135deg, #30D158 0%, #34C759 100%);

  /* 功能色（iOS/macOS 風格） */
  --color-success: #30D158;
  --color-warning: #FF9F0A;
  --color-error: #FF453A;
  --color-info: #64D2FF;

  /* 聊天氣泡 */
  --color-chat-user-bg: #2C3E50;
  --color-chat-assistant-bg: #1E1E24;
  --color-chat-user-border: #8AB4F8;
  --color-chat-assistant-border: #5F6368;

  /* === 字體系統 === */
  --font-family-base: 'Segoe UI', 'Noto Sans TC', 'Microsoft JhengHei', system-ui, -apple-system, sans-serif;
  --font-family-display: 'Inter', 'SF Pro Display', var(--font-family-base);
  --font-family-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;

  /* 字體大小 - 更大更清晰 */
  --font-size-xs: 14px;
  --font-size-sm: 16px;
  --font-size-md: 18px;
  --font-size-lg: 22px;
  --font-size-xl: 28px;
  --font-size-xxl: 36px;
  --font-size-hero: 48px;

  /* === 間距系統 === */
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;
  --spacing-2xl: 48px;
  --spacing-3xl: 64px;

  /* === 圓角 === */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* === 陰影系統 - 立體感 === */
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 0 24px rgba(138, 180, 248, 0.3);
  --shadow-glow-strong: 0 0 40px rgba(138, 180, 248, 0.5);

  /* === 動畫時間 === */
  --transition-fast: 150ms;
  --transition-base: 250ms;
  --transition-slow: 350ms;
  --transition-slower: 500ms;

  /* === 模糊效果 === */
  --blur-sm: blur(8px);
  --blur-md: blur(16px);
  --blur-lg: blur(24px);
}

/* === 全域重置 === */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html, body {
  height: 100%;
  overflow: hidden;
}

body {
  font-family: var(--font-family-base);
  font-size: var(--base-font-size); /* 使用可調整的基準字體大小 */
  line-height: 1.6;
  color: var(--color-text-primary);
  background: var(--color-bg-primary);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* === 應用程式主框架 === */
#app {
  display: flex;
  flex-direction: column;
  height: 100vh;
  background: var(--color-bg-primary);
  position: relative;
}

/* 背景動態效果 */
#app::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background:
    radial-gradient(circle at 20% 80%, rgba(102, 126, 234, 0.1) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(118, 75, 162, 0.08) 0%, transparent 50%);
  pointer-events: none;
  z-index: 0;
}

/* === 頭部區域 - 現代化設計 === */
.app-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-lg) var(--spacing-xl);
  background: rgba(20, 20, 25, 0.8);
  backdrop-filter: var(--blur-md);
  border-bottom: 1px solid rgba(138, 180, 248, 0.1);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
  position: relative;
  z-index: 100;
}

.app-title {
  font-family: var(--font-family-display);
  font-size: var(--font-size-xl);
  font-weight: 600;
  background: var(--gradient-secondary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.02em;
}

.header-controls {
  display: flex;
  gap: var(--spacing-md);
  align-items: center;
}

/* 現代化按鈕（Apple 風格） */
.icon-btn {
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  background: rgba(10, 132, 255, 0.12);
  border: 1px solid rgba(10, 132, 255, 0.25);
  border-radius: var(--radius-md);
  color: var(--color-accent-primary);
  cursor: pointer;
  transition: all var(--transition-base) cubic-bezier(0.25, 0.46, 0.45, 0.94);
  position: relative;
  overflow: hidden;
}

.icon-btn::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(10, 132, 255, 0.15);
  transform: translate(-50%, -50%);
  transition: width var(--transition-base), height var(--transition-base);
}

.icon-btn:hover {
  background: rgba(10, 132, 255, 0.2);
  border-color: var(--color-accent-primary);
  transform: scale(1.05);
  box-shadow: 0 0 20px rgba(10, 132, 255, 0.4);
}

.icon-btn:hover::before {
  width: 100%;
  height: 100%;
}

.icon-btn:active {
  transform: scale(0.98);
}

/* === 主要內容區 === */
.app-main {
  display: grid;
  grid-template-columns: 300px 1fr 360px;
  gap: 0;
  flex: 1;
  overflow: hidden;
  position: relative;
  z-index: 1;
}

/* === 側邊欄 - 玻璃擬態設計 === */
.sidebar {
  background: rgba(20, 20, 25, 0.6);
  backdrop-filter: var(--blur-md);
  border-right: 1px solid rgba(138, 180, 248, 0.1);
  display: flex;
  flex-direction: column;
  position: relative;
}

.sidebar::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 200px;
  background: linear-gradient(180deg, rgba(138, 180, 248, 0.05) 0%, transparent 100%);
  pointer-events: none;
}

.sidebar-header {
  padding: var(--spacing-xl) var(--spacing-lg);
  border-bottom: 1px solid rgba(138, 180, 248, 0.1);
  position: relative;
  z-index: 1;
}

.sidebar-header h2 {
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin-bottom: var(--spacing-md);
  color: var(--color-text-primary);
}

.conversation-list {
  flex: 1;
  overflow-y: auto;
  padding: var(--spacing-md);
  position: relative;
  z-index: 1;
}

/* 自訂滾動條 - 極簡設計 */
.conversation-list::-webkit-scrollbar {
  width: 6px;
}

.conversation-list::-webkit-scrollbar-track {
  background: transparent;
}

.conversation-list::-webkit-scrollbar-thumb {
  background: rgba(138, 180, 248, 0.2);
  border-radius: var(--radius-full);
  transition: background var(--transition-base);
}

.conversation-list::-webkit-scrollbar-thumb:hover {
  background: rgba(138, 180, 248, 0.4);
}

/* 對話項目 - 卡片式設計 */
.conversation-item {
  padding: var(--spacing-md);
  margin-bottom: var(--spacing-sm);
  background: rgba(30, 30, 36, 0.6);
  border: 1px solid rgba(138, 180, 248, 0.1);
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-base) cubic-bezier(0.4, 0, 0.2, 1);
  position: relative;
  overflow: hidden;
}

.conversation-item::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--gradient-secondary);
  transform: scaleY(0);
  transition: transform var(--transition-base);
}

.conversation-item:hover {
  background: rgba(30, 30, 36, 0.9);
  border-color: rgba(138, 180, 248, 0.3);
  transform: translateX(4px);
  box-shadow: var(--shadow-md);
}

.conversation-item:hover::before {
  transform: scaleY(1);
}

.conversation-item.active {
  background: rgba(138, 180, 248, 0.1);
  border-color: var(--color-accent-primary);
  box-shadow: var(--shadow-glow);
}

.conversation-item.active::before {
  transform: scaleY(1);
}

.conversation-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-xs);
}

.conversation-title {
  font-size: var(--font-size-md);
  font-weight: 500;
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  color: var(--color-text-primary);
}

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

.conversation-actions {
  display: flex;
  gap: var(--spacing-xs);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.conversation-item:hover .conversation-actions,
.conversation-item.active .conversation-actions {
  opacity: 1;
}

.edit-title-btn,
.delete-conv-btn {
  font-size: var(--font-size-sm);
  padding: var(--spacing-xs);
  background: rgba(138, 180, 248, 0.1);
  border: 1px solid transparent;
  border-radius: var(--radius-sm);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.edit-title-btn:hover {
  background: rgba(138, 180, 248, 0.2);
  color: var(--color-accent-primary);
}

.delete-conv-btn:hover {
  background: rgba(242, 139, 130, 0.2);
  color: var(--color-error);
}

/* === 聊天容器 - 主要聊天區 === */
.chat-container {
  display: flex;
  flex-direction: column;
  background: var(--color-bg-primary);
  height: 100%;
  overflow: hidden;
  position: relative;
}

/* 歡迎畫面 - 英雄區域 */
.welcome-screen {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-3xl);
  position: relative;
}

.welcome-content {
  text-align: center;
  max-width: 700px;
  animation: fadeInUp 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.welcome-title {
  font-family: var(--font-family-display);
  font-size: var(--font-size-hero);
  font-weight: 700;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: var(--spacing-lg);
  letter-spacing: -0.03em;
  line-height: 1.2;
}

.welcome-subtitle {
  font-size: var(--font-size-xl);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-2xl);
  font-weight: 300;
}

.quick-actions {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-md);
  margin-top: var(--spacing-xl);
}

/* 快速操作按鈕 - 卡片式（Apple 風格） */
.quick-btn {
  padding: var(--spacing-xl);
  font-size: var(--font-size-md);
  font-weight: 500;
  background: rgba(30, 30, 36, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 14px;
  color: var(--color-text-primary);
  cursor: pointer;
  transition: all var(--transition-base) cubic-bezier(0.25, 0.46, 0.45, 0.94);
  position: relative;
  overflow: hidden;
  backdrop-filter: var(--blur-sm);
  letter-spacing: -0.01em;
}

.quick-btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: var(--gradient-secondary);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.quick-btn:hover {
  background: rgba(10, 132, 255, 0.12);
  border-color: var(--color-accent-primary);
  transform: scale(1.02);
  box-shadow: 0 4px 20px rgba(10, 132, 255, 0.25);
}

.quick-btn:hover::before {
  opacity: 0.08;
}

.quick-btn:active {
  transform: scale(0.98);
}

/* === 聊天訊息區 === */
.chat-messages {
  flex: 1;
  padding: var(--spacing-xl);
  overflow-y: auto;
  overflow-x: hidden;
  background: linear-gradient(180deg, var(--color-bg-primary) 0%, var(--color-bg-secondary) 100%);
}

.chat-messages::-webkit-scrollbar {
  width: 8px;
}

.chat-messages::-webkit-scrollbar-track {
  background: transparent;
}

.chat-messages::-webkit-scrollbar-thumb {
  background: rgba(138, 180, 248, 0.2);
  border-radius: var(--radius-full);
}

.chat-messages::-webkit-scrollbar-thumb:hover {
  background: rgba(138, 180, 248, 0.3);
}

/* 訊息氣泡 - 現代設計 */
.message {
  display: flex;
  margin-bottom: var(--spacing-xl);
  animation: messageSlideIn 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes messageSlideIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.message.user {
  justify-content: flex-end;
}

.message.assistant {
  justify-content: flex-start;
}

.message-content {
  max-width: 75%;
  padding: var(--spacing-lg) var(--spacing-xl);
  border-radius: var(--radius-xl);
  font-size: var(--font-size-md);
  line-height: 1.7;
  position: relative;
  backdrop-filter: var(--blur-sm);
}

.message.user .message-content {
  background: linear-gradient(135deg, rgba(138, 180, 248, 0.2) 0%, rgba(102, 158, 246, 0.15) 100%);
  border: 1px solid rgba(138, 180, 248, 0.3);
  box-shadow: 0 4px 16px rgba(138, 180, 248, 0.2);
}

.message.assistant .message-content {
  background: rgba(30, 30, 36, 0.8);
  border: 1px solid rgba(95, 99, 104, 0.3);
  box-shadow: var(--shadow-md);
}

.message-footer {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  margin-top: var(--spacing-sm);
}

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

.llm-badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  font-size: 11px;
  font-weight: 600;
  color: var(--color-text-primary);
  background: rgba(138, 180, 248, 0.2);
  border: 1px solid rgba(138, 180, 248, 0.3);
}

/* === Markdown 內容樣式 === */
.markdown-content {
  line-height: 1.8;
  color: var(--color-text-primary);
}

.markdown-content p {
  margin: var(--spacing-md) 0;
}

.markdown-content h1,
.markdown-content h2,
.markdown-content h3 {
  margin: var(--spacing-lg) 0 var(--spacing-md) 0;
  font-weight: 600;
  color: var(--color-text-primary);
}

.markdown-content h1 {
  font-size: var(--font-size-xl);
  border-bottom: 2px solid rgba(138, 180, 248, 0.3);
  padding-bottom: var(--spacing-sm);
}

.markdown-content h2 {
  font-size: var(--font-size-lg);
}

.markdown-content h3 {
  font-size: var(--font-size-md);
}

.markdown-content strong {
  font-weight: 600;
  color: var(--color-accent-primary);
}

.markdown-content code {
  font-family: var(--font-family-mono);
  font-size: var(--font-size-sm);
  background: rgba(138, 180, 248, 0.1);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  color: var(--color-accent-primary);
}

.markdown-content pre {
  background: rgba(20, 20, 25, 0.8);
  border: 1px solid rgba(138, 180, 248, 0.2);
  border-radius: var(--radius-md);
  padding: var(--spacing-lg);
  overflow-x: auto;
  margin: var(--spacing-md) 0;
}

.markdown-content pre code {
  background: none;
  padding: 0;
  color: var(--color-text-secondary);
}

.markdown-content ul,
.markdown-content ol {
  margin: var(--spacing-md) 0;
  padding-left: var(--spacing-xl);
}

.markdown-content li {
  margin: var(--spacing-sm) 0;
}

.markdown-content a {
  color: var(--color-accent-primary);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition-fast);
}

.markdown-content a:hover {
  border-bottom-color: var(--color-accent-primary);
}

/* === 輸入區域 - 現代化設計 === */
.input-container {
  padding: var(--spacing-xl);
  background: rgba(20, 20, 25, 0.8);
  backdrop-filter: var(--blur-md);
  border-top: 1px solid rgba(138, 180, 248, 0.1);
  position: relative;
}

.quick-shortcuts {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-sm);
  margin-bottom: var(--spacing-md);
}

.shortcut-btn {
  padding: var(--spacing-md);
  font-size: var(--font-size-sm);
  font-weight: 500;
  background: rgba(30, 30, 36, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 10px;
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-base) cubic-bezier(0.25, 0.46, 0.45, 0.94);
  letter-spacing: -0.01em;
}

.shortcut-btn:hover {
  background: rgba(10, 132, 255, 0.15);
  border-color: var(--color-accent-primary);
  color: var(--color-accent-primary);
  transform: scale(1.02);
}

.shortcut-btn:active {
  transform: scale(0.98);
}

.sos-btn {
  width: 100%;
  padding: var(--spacing-lg);
  margin-bottom: var(--spacing-md);
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: white;
  background: var(--color-error);
  border: none;
  border-radius: 12px;
  cursor: pointer;
  transition: all var(--transition-base) cubic-bezier(0.25, 0.46, 0.45, 0.94);
  box-shadow: 0 4px 16px rgba(255, 69, 58, 0.35);
  letter-spacing: -0.01em;
}

.sos-btn:hover {
  background: #FF5951;
  transform: scale(1.02);
  box-shadow: 0 6px 20px rgba(255, 69, 58, 0.5);
}

.sos-btn:active {
  transform: scale(0.98);
}

.input-wrapper {
  background: rgba(30, 30, 36, 0.8);
  border: 2px solid rgba(138, 180, 248, 0.2);
  border-radius: var(--radius-xl);
  padding: var(--spacing-md);
  transition: all var(--transition-base);
}

.input-wrapper:focus-within {
  border-color: var(--color-accent-primary);
  box-shadow: var(--shadow-glow);
}

.message-input {
  width: 100%;
  padding: var(--spacing-md);
  font-size: var(--font-size-md);
  font-family: inherit;
  color: var(--color-text-primary);
  background: transparent;
  border: none;
  outline: none;
  resize: none;
  min-height: 60px;
}

.message-input::placeholder {
  color: var(--color-text-tertiary);
}

.input-controls {
  display: flex;
  gap: var(--spacing-md);
  margin-top: var(--spacing-md);
}

/* === 按鈕系統（Apple & SpaceX 風格） === */
.btn {
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: var(--font-size-md);
  font-weight: 600;
  border: none;
  border-radius: 12px;
  cursor: pointer;
  transition: all var(--transition-base) cubic-bezier(0.25, 0.46, 0.45, 0.94);
  position: relative;
  overflow: hidden;
  letter-spacing: -0.01em;
}

.btn-primary {
  background: var(--color-accent-primary);
  color: white;
  box-shadow: 0 2px 8px rgba(10, 132, 255, 0.3);
}

.btn-primary:hover {
  background: var(--color-accent-hover);
  transform: scale(1.02);
  box-shadow: 0 4px 16px rgba(10, 132, 255, 0.4);
}

.btn-primary:active {
  transform: scale(0.98);
}

.btn-secondary {
  background: rgba(30, 30, 36, 0.8);
  color: var(--color-text-primary);
  border: 1px solid rgba(255, 255, 255, 0.15);
}

.btn-secondary:hover {
  background: rgba(60, 60, 67, 0.9);
  border-color: rgba(255, 255, 255, 0.25);
  transform: scale(1.02);
}

.btn-secondary:active {
  transform: scale(0.98);
}

.btn-voice {
  flex: 1;
  background: rgba(100, 210, 255, 0.15);
  color: #64D2FF;
  border: 1px solid rgba(100, 210, 255, 0.3);
}

.btn-voice:hover {
  background: rgba(100, 210, 255, 0.25);
  border-color: #64D2FF;
  transform: scale(1.02);
}

.btn-send {
  flex: 2;
  background: var(--color-accent-primary);
  color: white;
  box-shadow: 0 2px 8px rgba(10, 132, 255, 0.3);
}

.btn-send:hover {
  background: var(--color-accent-hover);
  transform: scale(1.02);
  box-shadow: 0 4px 16px rgba(10, 132, 255, 0.4);
}

.btn-danger {
  background: var(--color-error);
  color: white;
  box-shadow: 0 2px 8px rgba(255, 69, 58, 0.3);
}

.btn-danger:hover {
  background: #FF5951;
  transform: scale(1.02);
  box-shadow: 0 4px 16px rgba(255, 69, 58, 0.4);
}

/* === 資訊面板 === */
.info-panel {
  background: rgba(20, 20, 25, 0.6);
  backdrop-filter: var(--blur-md);
  border-left: 1px solid rgba(138, 180, 248, 0.1);
  padding: var(--spacing-xl);
  overflow-y: auto;
}

.info-panel::-webkit-scrollbar {
  width: 6px;
}

.info-panel::-webkit-scrollbar-thumb {
  background: rgba(138, 180, 248, 0.2);
  border-radius: var(--radius-full);
}

.panel-section {
  background: rgba(30, 30, 36, 0.6);
  padding: var(--spacing-lg);
  border-radius: var(--radius-lg);
  border: 1px solid rgba(138, 180, 248, 0.1);
  margin-bottom: var(--spacing-lg);
}

.panel-section h3 {
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin-bottom: var(--spacing-md);
  background: var(--gradient-secondary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stats {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.stat-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--spacing-md);
  background: rgba(138, 180, 248, 0.05);
  border-radius: var(--radius-md);
  border: 1px solid rgba(138, 180, 248, 0.1);
}

.stat-label {
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
}

.stat-value {
  font-size: var(--font-size-lg);
  font-weight: 600;
  color: var(--color-accent-primary);
}

/* === 模態框 === */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.8);
  backdrop-filter: var(--blur-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 10000;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.modal-content {
  background: var(--color-bg-secondary);
  padding: var(--spacing-2xl);
  border-radius: var(--radius-xl);
  border: 1px solid rgba(138, 180, 248, 0.2);
  box-shadow: var(--shadow-xl);
  max-width: 500px;
  width: 90%;
  animation: scaleIn 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.9);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.modal-title {
  font-size: var(--font-size-xl);
  font-weight: 600;
  margin-bottom: var(--spacing-md);
  color: var(--color-text-primary);
}

.modal-text {
  font-size: var(--font-size-md);
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xl);
  line-height: 1.6;
}

.modal-actions {
  display: flex;
  gap: var(--spacing-md);
}

.modal-actions .btn {
  flex: 1;
}

/* === 載入動畫 === */
.loading-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: transparent;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  pointer-events: none;
}

.loading-spinner {
  width: 50px;
  height: 50px;
  border: 3px solid rgba(138, 180, 248, 0.3);
  border-top-color: var(--color-accent-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
  box-shadow: 0 4px 12px rgba(138, 180, 248, 0.3);
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.loading-text {
  margin-top: var(--spacing-md);
  padding: var(--spacing-sm) var(--spacing-lg);
  font-size: var(--font-size-base);
  color: var(--color-text-primary);
  font-weight: 500;
  background: var(--color-surface-elevated);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
}

/* === 使用者資訊 === */
.user-info {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-sm) var(--spacing-md);
  background: rgba(138, 180, 248, 0.1);
  border: 1px solid rgba(138, 180, 248, 0.2);
  border-radius: var(--radius-full);
  margin-right: var(--spacing-md);
}

.user-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--color-accent-primary);
  box-shadow: 0 0 12px rgba(138, 180, 248, 0.3);
}

.user-name {
  color: var(--color-text-primary);
  font-size: var(--font-size-sm);
  font-weight: 500;
}

/* === 響應式設計 === */
@media (max-width: 1200px) {
  .app-main {
    grid-template-columns: 280px 1fr 320px;
  }
}

@media (max-width: 968px) {
  .app-main {
    grid-template-columns: 1fr;
  }

  .sidebar,
  .info-panel {
    display: none;
  }

  .quick-actions {
    grid-template-columns: 1fr;
  }

  .quick-shortcuts {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* === 漢堡選單 === */
.mobile-menu-btn {
  display: none;
}

@media (max-width: 968px) {
  .mobile-menu-btn {
    display: flex;
  }
}

/* === 側邊欄遮罩 === */
.sidebar-overlay {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: var(--blur-md);
  z-index: 1000;
  opacity: 0;
  transition: opacity var(--transition-base);
}

.sidebar-overlay.active {
  display: block;
  opacity: 1;
}

/* === 快速功能模態框 === */
.quick-functions-btn {
  display: none;
}

.quick-functions-content {
  max-width: 500px;
  width: 90%;
}

.quick-functions-list {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.quick-function-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  padding: var(--spacing-lg);
  background: rgba(30, 30, 36, 0.6);
  border: 1px solid rgba(138, 180, 248, 0.1);
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: all var(--transition-base);
}

.quick-function-item:hover {
  background: rgba(138, 180, 248, 0.15);
  border-color: var(--color-accent-primary);
  transform: translateX(4px);
}

.quick-icon {
  font-size: 32px;
}

.quick-text {
  font-size: var(--font-size-lg);
  font-weight: 500;
  color: var(--color-text-primary);
}

/* === 設定模態框 === */
.settings-modal {
  max-width: 600px;
}

.setting-group {
  margin-bottom: var(--spacing-xl);
}

.setting-label {
  display: block;
  font-size: var(--font-size-md);
  font-weight: 500;
  margin-bottom: var(--spacing-sm);
  color: var(--color-text-primary);
}

.setting-select,
.setting-input {
  width: 100%;
  padding: var(--spacing-md);
  font-size: var(--font-size-md);
  background: rgba(30, 30, 36, 0.6);
  border: 1px solid rgba(10, 132, 255, 0.2);
  border-radius: var(--radius-md);
  color: var(--color-text-primary);
  transition: all var(--transition-base);
}

.setting-select:focus,
.setting-input:focus {
  outline: none;
  border-color: var(--color-accent-primary);
  box-shadow: var(--shadow-glow);
}

/* 字體大小選項 */
.font-size-options {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--spacing-sm);
}

.font-size-btn {
  padding: var(--spacing-md);
  font-size: var(--font-size-md);
  font-weight: 500;
  background: rgba(30, 30, 36, 0.6);
  border: 2px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-base) cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

.font-size-btn:hover {
  background: rgba(10, 132, 255, 0.15);
  border-color: var(--color-accent-primary);
  color: var(--color-accent-primary);
  transform: scale(1.05);
}

.font-size-btn.active {
  background: var(--color-accent-primary);
  border-color: var(--color-accent-primary);
  color: white;
  box-shadow: 0 2px 8px rgba(10, 132, 255, 0.4);
}

/* 主題選項 */
.theme-options {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-sm);
}

.theme-btn {
  padding: var(--spacing-lg);
  font-size: var(--font-size-md);
  font-weight: 500;
  background: rgba(30, 30, 36, 0.6);
  border: 2px solid rgba(255, 255, 255, 0.12);
  border-radius: var(--radius-md);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-base) cubic-bezier(0.25, 0.46, 0.45, 0.94);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
}

.theme-btn:hover {
  background: rgba(10, 132, 255, 0.15);
  border-color: var(--color-accent-primary);
  color: var(--color-accent-primary);
  transform: scale(1.02);
}

.theme-btn.active {
  background: var(--color-accent-primary);
  border-color: var(--color-accent-primary);
  color: white;
  box-shadow: 0 2px 8px rgba(10, 132, 255, 0.4);
}

/* === Toast 通知 === */
.toast {
  position: fixed;
  bottom: var(--spacing-xl);
  left: 50%;
  transform: translateX(-50%);
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: var(--font-size-md);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  z-index: 10000;
  animation: slideUp 0.3s ease-out;
}

@keyframes slideUp {
  from {
    transform: translate(-50%, 100px);
    opacity: 0;
  }
  to {
    transform: translate(-50%, 0);
    opacity: 1;
  }
}

.toast-success {
  background: linear-gradient(135deg, #81C995 0%, #4FACFE 100%);
  color: white;
}

.toast-error {
  background: linear-gradient(135deg, #F28B82 0%, #F5576C 100%);
  color: white;
}

/* === 空狀態 === */
.empty-state {
  color: var(--color-text-tertiary);
  font-style: italic;
  font-size: var(--font-size-sm);
}

/* === 輔助類別 === */
.desktop-only {
  display: block;
}

.mobile-only {
  display: none;
}

@media (max-width: 968px) {
  .desktop-only {
    display: none !important;
  }

  .mobile-only {
    display: block;
  }
}

/* ===================================
   淺色主題配色
   當 body 有 theme-light class 時套用
   =================================== */

body.theme-light {
  /* === 背景顏色 - 清新明亮（Dropbox 啟發） === */
  --color-bg-primary: #FFFFFF;
  --color-bg-secondary: #F7F9FA;
  --color-bg-tertiary: #EFF1F3;
  --color-bg-elevated: #FFFFFF;

  /* === 文字顏色 - 清晰易讀 === */
  --color-text-primary: #1E1919;
  --color-text-secondary: #5F6368;
  --color-text-tertiary: #7D8084;
  --color-text-disabled: #9FA6AD;

  /* === 強調色 - 專業藍色（Dropbox 風格） === */
  --color-accent-primary: #0061FF;
  --color-accent-secondary: #0051D5;
  --color-accent-hover: #1C74FF;

  /* === 漸層色 - 簡潔專業 === */
  --gradient-primary: linear-gradient(135deg, #0061FF 0%, #0051D5 100%);
  --gradient-secondary: linear-gradient(135deg, #0061FF 0%, #0051D5 100%);
  --gradient-accent: linear-gradient(135deg, #FF385C 0%, #E61E4D 100%);
  --gradient-success: linear-gradient(135deg, #00D084 0%, #00B878 100%);

  /* === 功能色（清晰明確） === */
  --color-success: #00D084;
  --color-warning: #FF9F0A;
  --color-error: #FF385C;
  --color-info: #0061FF;

  /* === 聊天氣泡 === */
  --color-chat-user-bg: #E3F2FD;
  --color-chat-assistant-bg: #F7F9FA;
  --color-chat-user-border: #0061FF;
  --color-chat-assistant-border: #DFE1E6;

  /* === 陰影系統 - 柔和自然（Dropbox 風格） === */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.12);
  --shadow-xl: 0 8px 32px rgba(0, 0, 0, 0.16);
  --shadow-glow: 0 0 20px rgba(0, 97, 255, 0.15);
  --shadow-glow-strong: 0 0 32px rgba(0, 97, 255, 0.25);
}

/* === 淺色主題專屬調整 === */

/* 背景漸層效果調整（Dropbox 風格 - 極簡） */
body.theme-light #app::before {
  background:
    radial-gradient(circle at 20% 80%, rgba(0, 97, 255, 0.03) 0%, transparent 50%),
    radial-gradient(circle at 80% 20%, rgba(0, 97, 255, 0.02) 0%, transparent 50%);
}

/* 頭部區域（Dropbox 風格 - 乾淨） */
body.theme-light .app-header {
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid #EFF1F3;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
}

/* 側邊欄 */
body.theme-light .sidebar {
  background: rgba(248, 249, 250, 0.95);
  backdrop-filter: blur(16px);
  border-right: 1px solid rgba(0, 0, 0, 0.08);
}

body.theme-light .sidebar::before {
  background: linear-gradient(180deg, rgba(33, 150, 243, 0.03) 0%, transparent 100%);
}

body.theme-light .sidebar-header {
  border-bottom: 1px solid rgba(0, 0, 0, 0.08);
}

/* 對話項目 */
body.theme-light .conversation-item {
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid rgba(0, 0, 0, 0.08);
}

body.theme-light .conversation-item:hover {
  background: rgba(255, 255, 255, 1);
  border-color: rgba(33, 150, 243, 0.3);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

body.theme-light .conversation-item.active {
  background: rgba(33, 150, 243, 0.08);
  border-color: var(--color-accent-primary);
  box-shadow: 0 0 20px rgba(33, 150, 243, 0.2);
}

/* 聊天訊息區 */
body.theme-light .chat-messages {
  background: linear-gradient(180deg, #FFFFFF 0%, #F8F9FA 100%);
}

/* 訊息氣泡（Dropbox 風格 - 清爽） */
body.theme-light .message.user .message-content {
  background: linear-gradient(135deg, rgba(0, 97, 255, 0.08) 0%, rgba(0, 97, 255, 0.06) 100%);
  border: 1px solid rgba(0, 97, 255, 0.2);
  box-shadow: 0 1px 4px rgba(0, 97, 255, 0.1);
}

body.theme-light .message.assistant .message-content {
  background: #F7F9FA;
  border: 1px solid #EFF1F3;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.06);
}

/* 輸入區域 */
body.theme-light .input-container {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(16px);
  border-top: 1px solid rgba(0, 0, 0, 0.08);
}

body.theme-light .input-wrapper {
  background: rgba(248, 249, 250, 0.8);
  border: 2px solid rgba(33, 150, 243, 0.2);
}

body.theme-light .input-wrapper:focus-within {
  border-color: var(--color-accent-primary);
  box-shadow: 0 0 20px rgba(33, 150, 243, 0.2);
}

body.theme-light .message-input::placeholder {
  color: #9E9E9E;
}

/* 快捷按鈕（Dropbox 風格） */
body.theme-light .shortcut-btn {
  background: #FFFFFF;
  border: 1px solid #DFE1E6;
  color: var(--color-text-secondary);
}

body.theme-light .shortcut-btn:hover {
  background: rgba(0, 97, 255, 0.06);
  border-color: var(--color-accent-primary);
  color: var(--color-accent-primary);
}

/* 快速操作按鈕（Dropbox 風格） */
body.theme-light .quick-btn {
  background: #FFFFFF;
  border: 1px solid #DFE1E6;
}

body.theme-light .quick-btn:hover {
  background: rgba(0, 97, 255, 0.04);
  border-color: var(--color-accent-primary);
  box-shadow: 0 2px 12px rgba(0, 97, 255, 0.12);
}

/* 資訊面板 */
body.theme-light .info-panel {
  background: rgba(248, 249, 250, 0.95);
  backdrop-filter: blur(16px);
  border-left: 1px solid rgba(0, 0, 0, 0.08);
}

body.theme-light .panel-section {
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid rgba(0, 0, 0, 0.08);
}

body.theme-light .stat-item {
  background: rgba(0, 97, 255, 0.04);
  border: 1px solid rgba(0, 97, 255, 0.08);
}

/* SOS 按鈕 */
body.theme-light .sos-btn {
  background: var(--color-error);
  box-shadow: 0 2px 8px rgba(255, 56, 92, 0.25);
}

body.theme-light .sos-btn:hover {
  background: #FF5270;
  box-shadow: 0 4px 12px rgba(255, 56, 92, 0.35);
}

/* 模態框 */
body.theme-light .modal {
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(8px);
}

body.theme-light .modal-content {
  background: #FFFFFF;
  border: 1px solid rgba(0, 0, 0, 0.12);
  box-shadow: 0 24px 48px rgba(0, 0, 0, 0.2);
}

/* 按鈕（Dropbox 風格） */
body.theme-light .btn-primary {
  background: var(--color-accent-primary);
  box-shadow: 0 1px 3px rgba(0, 97, 255, 0.2);
}

body.theme-light .btn-primary:hover {
  background: var(--color-accent-hover);
  box-shadow: 0 2px 8px rgba(0, 97, 255, 0.3);
}

body.theme-light .btn-secondary {
  background: #FFFFFF;
  border: 1px solid #DFE1E6;
  color: var(--color-text-primary);
}

body.theme-light .btn-secondary:hover {
  background: #F7F9FA;
  border-color: var(--color-accent-primary);
}

body.theme-light .btn-voice {
  background: rgba(0, 97, 255, 0.08);
  color: var(--color-accent-primary);
  border: 1px solid rgba(0, 97, 255, 0.2);
}

body.theme-light .btn-voice:hover {
  background: rgba(0, 97, 255, 0.15);
  border-color: var(--color-accent-primary);
}

body.theme-light .btn-send {
  background: var(--color-accent-primary);
  box-shadow: 0 1px 3px rgba(0, 97, 255, 0.2);
}

body.theme-light .btn-send:hover {
  background: var(--color-accent-hover);
  box-shadow: 0 2px 8px rgba(0, 97, 255, 0.3);
}

/* Icon 按鈕（Dropbox 風格 - 簡潔） */
body.theme-light .icon-btn {
  background: rgba(0, 97, 255, 0.06);
  border: 1px solid rgba(0, 97, 255, 0.15);
  color: var(--color-accent-primary);
}

body.theme-light .icon-btn:hover {
  background: rgba(0, 97, 255, 0.12);
  border-color: var(--color-accent-primary);
  box-shadow: 0 2px 8px rgba(0, 97, 255, 0.15);
}

/* 設定相關（Dropbox 風格） */
body.theme-light .setting-select,
body.theme-light .setting-input {
  background: #FFFFFF;
  border: 1px solid #DFE1E6;
  color: var(--color-text-primary);
}

body.theme-light .setting-select:focus,
body.theme-light .setting-input:focus {
  border-color: var(--color-accent-primary);
  box-shadow: 0 0 0 3px rgba(0, 97, 255, 0.1);
}

/* 字體大小按鈕（淺色主題） */
body.theme-light .font-size-btn {
  background: #FFFFFF;
  border: 2px solid #DFE1E6;
  color: var(--color-text-secondary);
}

body.theme-light .font-size-btn:hover {
  background: rgba(0, 97, 255, 0.06);
  border-color: var(--color-accent-primary);
  color: var(--color-accent-primary);
}

body.theme-light .font-size-btn.active {
  background: var(--color-accent-primary);
  border-color: var(--color-accent-primary);
  color: white;
  box-shadow: 0 2px 8px rgba(0, 97, 255, 0.3);
}

/* 主題按鈕（淺色主題） */
body.theme-light .theme-btn {
  background: #FFFFFF;
  border: 2px solid #DFE1E6;
  color: var(--color-text-secondary);
}

body.theme-light .theme-btn:hover {
  background: rgba(0, 97, 255, 0.06);
  border-color: var(--color-accent-primary);
  color: var(--color-accent-primary);
}

body.theme-light .theme-btn.active {
  background: var(--color-accent-primary);
  border-color: var(--color-accent-primary);
  color: white;
  box-shadow: 0 2px 8px rgba(0, 97, 255, 0.3);
}

/* 快速功能項目 */
body.theme-light .quick-function-item {
  background: rgba(255, 255, 255, 0.9);
  border: 1px solid rgba(0, 0, 0, 0.08);
}

body.theme-light .quick-function-item:hover {
  background: rgba(33, 150, 243, 0.08);
  border-color: var(--color-accent-primary);
}

/* 滾動條（Dropbox 風格 - 細緻） */
body.theme-light .conversation-list::-webkit-scrollbar-thumb,
body.theme-light .chat-messages::-webkit-scrollbar-thumb,
body.theme-light .info-panel::-webkit-scrollbar-thumb {
  background: rgba(0, 97, 255, 0.2);
}

body.theme-light .conversation-list::-webkit-scrollbar-thumb:hover,
body.theme-light .chat-messages::-webkit-scrollbar-thumb:hover,
body.theme-light .info-panel::-webkit-scrollbar-thumb:hover {
  background: rgba(0, 97, 255, 0.4);
}

/* 側邊欄遮罩 */
body.theme-light .sidebar-overlay {
  background: rgba(0, 0, 0, 0.4);
}

/* Markdown 內容（Dropbox 風格） */
body.theme-light .markdown-content code {
  background: rgba(0, 97, 255, 0.06);
  color: var(--color-accent-primary);
  border: 1px solid rgba(0, 97, 255, 0.1);
}

body.theme-light .markdown-content pre {
  background: #F7F9FA;
  border: 1px solid #EFF1F3;
}

body.theme-light .markdown-content blockquote {
  border-left: 4px solid var(--color-accent-primary);
  background-color: rgba(0, 97, 255, 0.03);
}

/* LLM Badge（Dropbox 風格） */
body.theme-light .llm-badge {
  background: rgba(0, 97, 255, 0.08);
  border: 1px solid rgba(0, 97, 255, 0.2);
  color: var(--color-accent-primary);
}

/* 編輯/刪除按鈕（Dropbox 風格） */
body.theme-light .edit-title-btn {
  background: rgba(0, 97, 255, 0.04);
}

body.theme-light .edit-title-btn:hover {
  background: rgba(0, 97, 255, 0.1);
  color: var(--color-accent-primary);
}

body.theme-light .delete-conv-btn:hover {
  background: rgba(255, 56, 92, 0.1);
  color: var(--color-error);
}