* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --primary: #667eea;
  --primary-dark: #5a67d8;
  --bg-color: #f7fafc;
  --card-bg: #ffffff;
  --text-color: #2d3748;
  --text-light: #718096;
  --border-color: #e2e8f0;
  --user-msg: #667eea;
  --ai-msg: #f7fafc;
  --shadow: 0 2px 8px rgba(0,0,0,0.1);
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: var(--bg-color);
  color: var(--text-color);
  line-height: 1.6;
}

#app {
  min-height: 100vh;
  min-height: 100dvh;
}

/* ==================== 对话列表页面 ==================== */

.conversation-list-page {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  min-height: 100dvh;
  background: var(--card-bg);
}

.list-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 16px;
  background: linear-gradient(135deg, var(--primary) 0%, #764ba2 100%);
  color: white;
  position: sticky;
  top: 0;
  z-index: 100;
}

.list-header .header-title {
  display: flex;
  align-items: center;
  gap: 10px;
}

.list-header .logo {
  font-size: 24px;
}

.list-header h1 {
  font-size: 18px;
  font-weight: 600;
}

.list-content {
  flex: 1;
  padding: 16px;
  overflow-y: auto;
}

.new-chat-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 20px;
  background: linear-gradient(135deg, var(--primary) 0%, #764ba2 100%);
  color: white;
  border: none;
  border-radius: 12px;
  font-size: 16px;
  cursor: pointer;
  margin-bottom: 16px;
  transition: transform 0.2s;
}

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

.conversation-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.empty-list {
  text-align: center;
  padding: 40px;
  color: var(--text-light);
}

.conversation-item {
  display: flex;
  flex-direction: column;
  padding: 12px 16px;
  background: white;
  border: 1px solid var(--border-color);
  border-radius: 12px;
  cursor: pointer;
  transition: all 0.2s;
  position: relative;
}

.conversation-item:hover {
  border-color: var(--primary);
  background: rgba(102, 126, 234, 0.05);
}

.conversation-item:active {
  background: rgba(102, 126, 234, 0.1);
}

.conv-title {
  font-size: 16px;
  font-weight: 500;
  color: var(--text-color);
  margin-bottom: 4px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.conv-meta {
  font-size: 12px;
  color: var(--text-light);
}

.conv-delete-btn {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  background: transparent;
  border: none;
  color: var(--text-light);
  padding: 6px;
  cursor: pointer;
  opacity: 0;
  transition: all 0.2s;
}

.conversation-item:hover .conv-delete-btn {
  opacity: 1;
}

.conv-delete-btn:hover {
  color: #e53e3e;
}

/* ==================== 对话页面 ==================== */

#chatPage {
  display: flex;
  flex-direction: column;
  height: 100vh;
  height: 100dvh;
  max-width: 800px;
  margin: 0 auto;
  background: var(--card-bg);
  box-shadow: var(--shadow);
}

.header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 16px;
  background: linear-gradient(135deg, var(--primary) 0%, #764ba2 100%);
  color: white;
  position: sticky;
  top: 0;
  z-index: 100;
}

.back-btn {
  background: transparent;
  border: none;
  color: white;
  padding: 8px;
  cursor: pointer;
  display: flex;
  align-items: center;
}

.back-btn:active {
  opacity: 0.8;
}

.header-title {
  display: flex;
  align-items: center;
  gap: 10px;
  flex: 1;
  margin-left: 8px;
}

.header-title h1 {
  font-size: 16px;
  font-weight: 600;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.logo {
  font-size: 20px;
}

.clear-btn {
  background: rgba(255,255,255,0.2);
  border: none;
  border-radius: 8px;
  padding: 8px;
  color: white;
  cursor: pointer;
}

.clear-btn:active {
  background: rgba(255,255,255,0.3);
}

.messages-container {
  flex: 1;
  overflow-y: auto;
  padding: 16px;
  -webkit-overflow-scrolling: touch;
}

.welcome {
  text-align: center;
  padding: 40px 20px;
}

.welcome-icon {
  font-size: 48px;
  margin-bottom: 16px;
}

.welcome h2 {
  font-size: 20px;
  margin-bottom: 8px;
}

.welcome p {
  color: var(--text-light);
  margin-bottom: 24px;
}

.quick-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
}

.quick-actions button {
  padding: 8px 16px;
  border: 1px solid var(--primary);
  background: white;
  color: var(--primary);
  border-radius: 20px;
  font-size: 14px;
  cursor: pointer;
}

.quick-actions button:active {
  background: var(--primary);
  color: white;
}

.messages {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.message {
  display: flex;
  gap: 12px;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.message.user {
  flex-direction: row-reverse;
}

.message-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  flex-shrink: 0;
}

.message.user .message-avatar {
  background: var(--user-msg);
  color: white;
}

.message.assistant .message-avatar {
  background: var(--primary);
  color: white;
}

.message-content {
  padding: 12px 16px;
  border-radius: 18px;
  word-wrap: break-word;
}

.message.user .message-content {
  background: var(--user-msg);
  color: white;
  border-bottom-right-radius: 4px;
}

.message.assistant .message-content {
  background: var(--ai-msg);
  color: var(--text-color);
  border-bottom-left-radius: 4px;
  border: 1px solid var(--border-color);
}

.message-content code {
  background: rgba(0,0,0,0.1);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: 'Monaco', 'Menlo', monospace;
  font-size: 0.9em;
}

.message-content pre {
  background: #1a1a2e;
  color: #eee;
  padding: 12px;
  border-radius: 8px;
  overflow-x: auto;
  margin: 8px 0;
}

.message-content pre code {
  background: transparent;
  padding: 0;
}

.message.user .message-content pre {
  background: rgba(0,0,0,0.2);
}

/* 流式输出光标 */
.streaming-cursor {
  animation: blink 1s infinite;
  color: var(--primary);
  font-weight: bold;
}

@keyframes blink {
  0%, 50% { opacity: 1; }
  51%, 100% { opacity: 0; }
}

/* 消息结构 */
.message-body {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.message.user .message-body {
  max-width: 85%;
}

.message.assistant .message-body {
  max-width: 80%;
}

/* 消息操作按钮 */
.message-actions {
  display: flex;
  gap: 6px;
  opacity: 0;
  transition: opacity 0.2s;
}

.message:hover .message-actions {
  opacity: 1;
}

.action-btn {
  background: transparent;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 4px 6px;
  color: var(--text-light);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
}

.action-btn:hover {
  background: var(--border-color);
  color: var(--text-color);
}

.action-btn.copy-btn:hover {
  background: #dbeafe;
  border-color: var(--primary);
  color: var(--primary);
}

.action-btn.delete-btn:hover {
  background: #fee2e2;
  border-color: #e53e3e;
  color: #e53e3e;
}

.action-btn.regenerate-btn:hover {
  background: #dbeafe;
  border-color: var(--primary);
  color: var(--primary);
}

/* Markdown 内容样式 */
.message-content h1, .message-content h2, .message-content h3 {
  margin: 12px 0 8px;
  font-weight: 600;
}

.message-content h1 { font-size: 1.3em; }
.message-content h2 { font-size: 1.2em; }
.message-content h3 { font-size: 1.1em; }

.message-content ul, .message-content ol {
  margin: 8px 0;
  padding-left: 20px;
}

.message-content li {
  margin: 4px 0;
}

.message-content strong {
  font-weight: 600;
}

.message-content em {
  font-style: italic;
}

.message-content a {
  color: var(--primary);
  text-decoration: underline;
}

.message-content blockquote {
  margin: 8px 0;
  padding: 8px 12px;
  border-left: 3px solid var(--primary);
  background: rgba(102, 126, 234, 0.1);
  border-radius: 4px;
}

.message-content table {
  margin: 8px 0;
  border-collapse: collapse;
  width: 100%;
}

.message-content th, .message-content td {
  border: 1px solid var(--border-color);
  padding: 6px 10px;
  text-align: left;
}

.message-content th {
  background: var(--bg-color);
  font-weight: 600;
}

/* 输入区域 */
.input-area {
  display: flex;
  gap: 10px;
  padding: 12px 16px;
  background: white;
  border-top: 1px solid var(--border-color);
  position: sticky;
  bottom: 0;
}

#userInput {
  flex: 1;
  padding: 12px 16px;
  border: 2px solid var(--border-color);
  border-radius: 24px;
  font-size: 16px;
  resize: none;
  outline: none;
  font-family: inherit;
  max-height: 120px;
  transition: border-color 0.2s;
}

#userInput:focus {
  border-color: var(--primary);
}

.send-btn {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--primary) 0%, #764ba2 100%);
  border: none;
  color: white;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.2s, opacity 0.2s;
  flex-shrink: 0;
}

.send-btn:active {
  transform: scale(0.95);
}

.send-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* Toast 提示 */
.toast {
  position: fixed;
  top: 80px;
  left: 50%;
  transform: translateX(-50%) translateY(-20px);
  background: var(--text-color);
  color: white;
  padding: 12px 24px;
  border-radius: 8px;
  font-size: 14px;
  opacity: 0;
  transition: all 0.3s ease;
  z-index: 1000;
  box-shadow: 0 4px 12px rgba(0,0,0,0.2);
}

.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

/* 安全区域适配（刘海屏） */
@supports (padding: env(safe-area-inset-bottom)) {
  .input-area {
    padding-bottom: calc(12px + env(safe-area-inset-bottom));
  }
}