:root {
  --bg-main: #0a0a23; /* 深藍背景 */
  --bg-panel: #1a1a3b;
  --bg-input: #2a2a4b;
  --bg-button: #4a90e2; /* 螢光藍 */
  --bg-button-hover: #9b59b6; /* 紫色光暈 */
  --bg-button-dis: #444;
  --color-text: #e0e0e0;
  --color-primary: #4a90e2;
  --color-success: #32cd32;
  --color-error: #ff4d4d;
  --radius: 10px; /* 圓潤邊角 */
  --transition: 0.3s ease;
  --glow: 0 0 8px rgba(74, 144, 226, 0.5);
}

/* ---------- 基礎排版 ---------- */
html,
body {
  margin: 0;
  padding: 0;
  height: 100%;
  font-family: 'Roboto', system-ui, -apple-system, BlinkMacSystemFont,
    'Segoe UI', Arial, sans-serif;
  background: var(--bg-main);
  color: var(--color-text);
  overflow-y: auto; /* 允許頁面滾動 */
}

/* ---------- 設定切換按鈕 ---------- */
#settingsToggle {
  position: fixed;
  left: 10px;
  top: 10px;
  background: var(--bg-button);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  padding: 0.5rem;
  cursor: grab;
  z-index: 1001;
  transition: var(--transition);
  box-shadow: var(--glow);
  touch-action: none; /* 確保拖曳功能在移動端順暢 */
}
#settingsToggle:active {
  cursor: grabbing;
}
#settingsToggle:hover {
  background: var(--bg-button-hover);
  box-shadow: 0 0 12px rgba(155, 89, 182, 0.7);
}

/* ---------- 設定選單 ---------- */
.settings-menu {
  position: fixed;
  top: 3rem;
  left: 1rem;
  background: var(--bg-panel);
  border-radius: var(--radius);
  padding: 1rem;
  box-shadow: var(--glow);
  z-index: 1000;
  transition: opacity 0.3s ease, transform 0.3s ease;
  transform: translateY(-20px);
  opacity: 0;
}
.settings-menu:not(.hidden) {
  opacity: 1;
  transform: translateY(0);
}
.settings-content {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.settings-content label {
  font-size: 0.9rem;
  color: var(--color-text);
}
.settings-content select,
.settings-content input {
  background: var(--bg-input);
  color: var(--color-text);
  border: 1px solid #444;
  border-radius: var(--radius);
  padding: 0.5rem;
}

/* ---------- 主容器 ---------- */
.main-container {
  display: flex;
  flex-direction: column;
  height: 100vh; /* 限制在視窗高度 */
}

/* ---------- 狀態列 ---------- */
.status-bar {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 0.5rem 1rem;
  background: var(--bg-panel);
  border-bottom: 1px solid #333;
  flex-shrink: 0;
  position: relative;
}

/* 歡迎訊息(可點擊) */
.welcome-message {
  font-size: 0.95rem;
  color: var(--color-success);
  cursor: pointer;
}

/* ---------- 狀態燈 ---------- */
.status-light {
  width: 12px;
  height: 12px;
  background: #555;
  border-radius: 50%;
  box-shadow: var(--glow);
}
.status-light.online  { background: var(--color-success); box-shadow: 0 0 8px rgba(50,205,50,0.7); }
.status-light.offline { background: #555; box-shadow: none; }
.status-light.busy    { background: #f59e0b; box-shadow: 0 0 8px rgba(245,158,11,0.6); }

/* ---------- 使用者清單 ---------- */
#userListPanel {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  left: auto;
  background: var(--bg-panel);
  border: 1px solid #444;
  border-radius: var(--radius);
  padding: 0.5rem;
  max-height: 240px;
  min-width: 200px;
  overflow-y: auto;
  z-index: 10;
}
.user-item {
  padding: 0.3rem;
  border-bottom: 1px solid #333;
  color: var(--color-text);
}
.user-item:last-child {
  border-bottom: none;
}

/* 麥克風圖示(開/關) */
/* (省略，因為圖標是 data URL) */

/* ---------- 主區塊 ---------- */
.main {
  flex: 1;
  display: flex;
  flex-direction: column;
  position: relative;
  min-height: 0;
}

/* ---------- 聊天階段 ---------- */
.stage {
  flex: 1 1 auto;
  overflow-y: auto;
  padding: 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.8rem;
  scrollbar-width: thin;
  scrollbar-color: #444 #222;
  -webkit-overflow-scrolling: touch;
  overscroll-behavior: contain;
}
.stage::-webkit-scrollbar {
  width: 8px;
}
.stage::-webkit-scrollbar-thumb {
  background: #444;
  border-radius: 4px;
}
.stage::-webkit-scrollbar-track {
  background: #222;
}

/* ---------- typing indicator (保持原樣) ---------- */
.typing-indicator {
  align-self: flex-start;
  display: flex;
  gap: 0.3rem;
  margin: 0.5rem;
}
.pulse-dot {
  width: 8px;
  height: 8px;
  background: var(--color-primary);
  border-radius: 50%;
  animation: pulse 1.2s infinite ease-in-out;
}
.pulse-dot:nth-child(2) { animation-delay: 0.2s; }
.pulse-dot:nth-child(3) { animation-delay: 0.4s; }
@keyframes pulse {
  0%   { transform: scale(1);   opacity: 0.5; }
  50%  { transform: scale(1.5); opacity: 1;   }
  100% { transform: scale(1);   opacity: 0.5; }
}
.typing-indicator.hidden { display: none; }

/* ---------- 進度條 (保持原樣) ---------- */
.progress-bar {
  width: 100%;
  height: 5px;
  background: #222;
  position: absolute;
  top: 0;
  left: 0;
  pointer-events: none;
}
.progress-bar.hidden { display: none; }
.progress-fill {
  height: 100%;
  background: linear-gradient(90deg, var(--color-primary), var(--bg-button-hover));
  transition: width 0.1s linear;
  box-shadow: var(--glow);
}

/* ---------- 輸入列 (保持原樣) ---------- */
.input-row {
  display: flex;
  gap: 0.5rem;
  padding: 1rem;
  background: var(--bg-panel);
  border-top: 1px solid #333;
  align-items: center;
  flex-shrink: 0;
  position: sticky;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 10;
  padding-bottom: calc(1rem + env(safe-area-inset-bottom));
}
.input-row textarea {
  flex: 1;
  resize: vertical;
  min-height: 3.5rem;
  background: var(--bg-input);
  color: var(--color-text);
  border: 1px solid #444;
  border-radius: var(--radius);
  padding: 0.8rem;
  font-size: 1rem;
  transition: box-shadow 0.3s ease;
}
.input-row textarea:focus {
  outline: none;
  box-shadow: 0 0 10px rgba(74, 144, 226, 0.5);
}
.input-buttons {
  display: flex;
  gap: 0.5rem;
}

/* ---------- 按鈕 (保持原樣) ---------- */
button {
  background: var(--bg-button);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  padding: 0.6rem 1.2rem;
  cursor: pointer;
  transition: var(--transition);
  font-size: 0.9rem;
  box-shadow: var(--glow);
}
button:disabled {
  background: var(--bg-button-dis);
  cursor: not-allowed;
  box-shadow: none;
}
button:hover:not(:disabled) {
  background: var(--bg-button-hover);
  box-shadow: 0 0 12px rgba(155, 89, 182, 0.7);
}
button:focus {
  outline: none;
}
button:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* ---------- 使用者訊息 (已優化) ---------- */
.user-line {
  align-self: flex-end;
  background: linear-gradient(135deg, var(--color-primary), var(--bg-button-hover));
  color: #fff;
  padding: 1rem;
  border-radius: var(--radius);
  margin: 0.5rem 0;
  max-width: 70%;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.3);
  border: 1px solid rgba(155, 89, 182, 0.3);
  transition: opacity 0.3s ease, transform 0.3s ease;
  width: fit-content; 
  margin-left: auto; 
}
.user-line > div {
  overflow-wrap: anywhere;
  word-break: break-word;
}

/* ---------- 助手回覆 (核心修正) ---------- */
.assistant-line {
  align-self: flex-start;
  display: block; /* 修正：使用 block 讓內容自然堆疊 */
  
  background: var(--bg-panel);
  color: var(--color-text);
  padding: 1rem;
  border-radius: var(--radius);
  margin: 0.5rem 0;
  
  max-width: 70%;
  width: fit-content; /* 修正：讓泡泡寬度適應內容 */
  
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.3);
  border: 1px solid rgba(74, 144, 226, 0.3);
  transition: opacity 0.3s ease, transform 0.3s ease;
}

.assistant-line > div { 
  min-width: 0;
  overflow-wrap: anywhere;
  word-break: break-word;
  width: 100%;
}

/* ---------- 系統訊息 (保持原樣) ---------- */
.system-line {
  align-self: center;
  text-align: center;
  font-size: 0.85rem;
  color: var(--color-success);
  margin: 0.5rem 0;
  white-space: pre-line;
}
.system-line.error {
  color: var(--color-error);
  font-weight: bold;
}

/* ---------- 模態視窗 (保持原樣) ---------- */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.8);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 999;
}
.modal-content {
  background: var(--bg-panel);
  padding: 2rem;
  border-radius: var(--radius);
  text-align: center;
  box-shadow: 0 0 12px rgba(74, 144, 226, 0.5);
  animation: fadeIn 0.3s ease;
}
.modal-buttons {
  display: flex;
  justify-content: center;
  gap: 1rem;
  margin-top: 1rem;
}
.modal-buttons button {
  background: var(--bg-button);
  color: #fff;
  border: none;
  border-radius: var(--radius);
  padding: 0.6rem 1.5rem;
  font-size: 1rem;
  cursor: pointer;
  transition: var(--transition);
  box-shadow: var(--glow);
}
.modal-buttons button:hover {
  background: var(--bg-button-hover);
  box-shadow: 0 0 12px rgba(155, 89, 182, 0.7);
}
.hidden { display: none; }

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

/* ---------- 思考與搜尋區塊 (保持原樣) ---------- */
.thinking-block,
.search-prompt-block {
  background: var(--bg-panel);
  border-left: 4px solid var(--color-primary);
  border-radius: var(--radius);
  padding: 1rem;
  margin: 0.5rem 0;
  color: var(--color-text);
  box-shadow: var(--glow);
  overflow-y: auto;
}
.thinking-block summary,
.search-prompt-block summary {
  font-weight: bold;
  cursor: pointer;
  color: var(--color-primary);
  outline: none;
  transition: var(--transition);
}
.thinking-block[open] summary,
.search-prompt-block[open] summary {
  color: var(--bg-button-hover);
}
.thinking-block div,
.search-prompt-block div {
  margin-top: 0.5rem;
  white-space: pre-line;
  font-size: 0.9rem;
  opacity: 0.9;
}

/* 暱稱輸入框 (保持原樣) */
#nicknameInput {
  width: 100%;
  padding: 0.8rem;
  font-size: 1rem;
  border-radius: var(--radius);
  border: 1px solid #444;
  background: var(--bg-input);
  color: var(--color-text);
  box-shadow: var(--glow);
  transition: box-shadow var(--transition);
}

#nicknameInput:focus {
  outline: none;
  box-shadow: 0 0 10px rgba(74, 144, 226, 0.7);
}

/* 暱稱對話框標題 (保持原樣) */
#nicknameDialog p {
  font-size: 1.1rem;
  font-weight: bold;
  color: var(--color-primary);
  margin-bottom: 1rem;
}

/* 語音按鈕 (保持原樣) */
.speech-button {
  margin-left: 10px;
  padding: 5px 10px;
  background-color: #28a745;
  color: #fff;
  border: none;
  border-radius: 5px;
  cursor: pointer;
  font-size: 16px;
  vertical-align: middle;
  transition: background-color 0.3s;
}
.speech-button:hover {
  background-color: #218838;
}
.response-time {
  display: block;
  margin-top: 5px;
  font-size: 12px;
  color: #6c757d;
  font-style: italic;
}

/* 語音播報指示 (保持原樣) */
.voice-indicator {
  align-self: center;
  background: var(--color-success);
  color: #fff;
  font-size: 0.85rem;
  padding: 0.5rem 1rem;
  border-radius: var(--radius);
  margin: 0.5rem 0;
  animation: speakPulse 1.2s infinite ease-in-out;
}

@keyframes speakPulse {
  0%   { transform: scale(1);   opacity: 0.6; }
  50%  { transform: scale(1.2); opacity: 1;   }
  100% { transform: scale(1);   opacity: 0.6; }
}

/* ---------- Markdown 與程式碼樣式 (保持原樣) ---------- */
.assistant-line a,
.user-line a {
  color: var(--color-primary);
  text-decoration: underline;
  text-underline-offset: 2px;
}
.assistant-line a:hover,
.user-line a:hover {
  color: var(--bg-button-hover);
}

.assistant-line pre,
.user-line pre {
  background: #111827;
  border: 1px solid #374151;
  border-radius: 8px;
  padding: 12px;
  overflow: auto;
  -webkit-overflow-scrolling: touch;
}
.assistant-line code,
.user-line code {
  background: #0b1020;
  padding: 0.15em 0.35em;
  border-radius: 4px;
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
}

.assistant-line p code,
.user-line p code {
    background: #0b1020; 
}

.assistant-line ul, .assistant-line ol,
.user-line ul, .user-line ol {
  padding-left: 1.2rem;
  margin: 0.4rem 0;
  text-align: left; /* 確保列表項目左對齊 */
}

/* ---------- 響應式設計 (保持原樣) ---------- */

/* 平板與小筆電：最大寬度 768px */
@media (max-width: 768px) {
  .input-row {
    flex-direction: column;
    align-items: stretch;
    padding: 0.5rem;
  }

  .input-buttons {
    display: flex;
    justify-content: flex-end;
  }

  .settings-menu {
    width: 80%;
    max-width: 300px;
  }

  .stage {
    max-height: none;
  }
  
  .user-line, .assistant-line {
    max-width: 90%;
  }
}

/* 中型手機：最大寬度 600px */
@media (max-width: 600px) {
  .assistant-line > div,
  .assistant-line > button,
  .assistant-line > span {
    width: 100%;
    max-width: 100%;
    word-break: break-word;
  }
}

/* 小型手機：最大寬度 480px */
@media (max-width: 480px) {
  .speech-button {
    font-size: 14px;
    padding: 4px 8px;
  }

  .modal-content {
    padding: 1rem;
  }
}

/* ---------- 語音播報按鈕樣式 (優化) ---------- */
.tts-play-btn {
  background: none;
  color: var(--color-primary);
  border: none;
  padding: 2px 0px;
  font-size: 16px;
  cursor: pointer;
  margin-right: 4px;
  line-height: 1; 
}

.tts-play-btn.generating {
  opacity: 0.7;
  color: #ffc107;
  animation: pulse-small 1s infinite;
}

.tts-play-btn.playing {
  color: var(--color-success);
}

.tts-play-btn::before {
  content: '🔊';
  font-weight: bold;
}

@keyframes pulse-small { 
  0%, 100% { opacity: 0.5; } 
  50% { opacity: 1; } 
}

/* ---------- 訊息結構 (保持原樣) ---------- */
.message-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
  margin-bottom: 0.3rem;
  color: #aaa;
}

.sender-nickname {
    font-weight: bold;
}

.message-content {
  font-size: 1rem;
  line-height: 1.6;
  white-space: pre-wrap;
  text-align: left; /* 確保內容靠左 */
}