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

:root {
  --bg-primary: #0f1419;
  --bg-secondary: #1a1f2e;
  --bg-tertiary: #252d3d;
  --text-primary: #e8eaed;
  --text-secondary: #9aa0a6;
  --accent: #1d9bf0;
  --accent-hover: #1a8cd8;
  --border: #2f3336;
  --success: #00ba7c;
  --error: #f4212e;
}

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

.app-container {
  display: flex;
  height: 100vh;
  overflow: hidden;
}

/* 侧边栏 */
.sidebar {
  width: 240px;
  background: var(--bg-secondary);
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  transition: transform 0.3s ease;
  flex-shrink: 0;
}

.sidebar-header {
  padding: 16px;
  border-bottom: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.sidebar-header h2 {
  font-size: 16px;
  font-weight: 600;
}

.sessions-list {
  flex: 1;
  overflow-y: auto;
  padding: 8px;
}

.session-item {
  padding: 12px;
  margin-bottom: 4px;
  border-radius: 8px;
  cursor: pointer;
  transition: background 0.2s;
  border: 1px solid transparent;
}

.session-item:hover {
  background: var(--bg-tertiary);
}

.session-item.active {
  background: var(--bg-tertiary);
  border-color: var(--accent);
}

.session-date {
  font-size: 11px;
  color: var(--text-secondary);
  margin-bottom: 4px;
}

.session-preview {
  font-size: 13px;
  color: var(--text-primary);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* 主内容区 */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.header {
  padding: 12px 20px;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 16px;
}

.header h1 {
  flex: 1;
  font-size: 18px;
  font-weight: 600;
}

.menu-toggle {
  display: none;
}

.model-selector select {
  background: var(--bg-tertiary);
  color: var(--text-primary);
  border: 1px solid var(--border);
  padding: 8px 12px;
  border-radius: 6px;
  font-size: 14px;
  cursor: pointer;
  outline: none;
}

.model-selector select:hover {
  border-color: var(--accent);
}

/* 聊天容器 */
.chat-container {
  flex: 1;
  overflow-y: auto;
  padding: 20px;
  position: relative;
}

.welcome-message {
  text-align: center;
  padding: 60px 20px;
  max-width: 700px;
  margin: 0 auto;
}

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

.welcome-message h2 {
  font-size: 24px;
  margin-bottom: 12px;
}

.welcome-message p {
  color: var(--text-secondary);
  margin-bottom: 32px;
}

.quick-actions {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 12px;
  max-width: 500px;
  margin: 0 auto;
}

.quick-btn {
  padding: 12px 16px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-primary);
  font-size: 14px;
  cursor: pointer;
  transition: all 0.2s;
}

.quick-btn:hover {
  background: var(--bg-secondary);
  border-color: var(--accent);
  transform: translateY(-2px);
}

/* 消息 */
.messages {
  max-width: 900px;
  margin: 0 auto;
  width: 100%;
}

.message {
  margin-bottom: 24px;
  animation: fadeIn 0.3s ease;
}

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

.message-header {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
  font-size: 13px;
  color: var(--text-secondary);
}

.message-role {
  font-weight: 600;
}

.message-model {
  padding: 2px 8px;
  background: var(--bg-tertiary);
  border-radius: 4px;
  font-size: 11px;
}

.message-content {
  padding: 16px;
  border-radius: 12px;
  line-height: 1.6;
  word-wrap: break-word;
  overflow-wrap: break-word;
}

.message.user .message-content {
  background: var(--accent);
  color: white;
  margin-left: 40px;
}

.message.assistant .message-content {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
}

.message-content pre {
  background: var(--bg-primary);
  padding: 12px;
  border-radius: 6px;
  overflow-x: auto;
  margin: 12px 0;
  border: 1px solid var(--border);
}

.message-content code {
  font-family: 'Monaco', 'Courier New', monospace;
  font-size: 13px;
  line-height: 1.5;
}

.message-content pre code {
  background: transparent;
  padding: 0;
  border: none;
}

.message-content p {
  margin: 0.8em 0;
}

.message-content p:first-child {
  margin-top: 0;
}

.message-content p:last-child {
  margin-bottom: 0;
}

.message-content table {
  width: 100%;
  border-collapse: collapse;
  margin: 12px 0;
  font-size: 14px;
  background: var(--bg-primary);
  border: 1px solid var(--border);
}

.message-content th,
.message-content td {
  padding: 10px 12px;
  border: 1px solid var(--border);
  text-align: left;
}

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

.message-content td {
  color: var(--text-secondary);
}

.message-content tr:hover {
  background: rgba(255, 255, 255, 0.02);
}

.loading-indicator {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 16px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: 12px;
  color: var(--text-secondary);
}

.loading-dots {
  display: flex;
  gap: 4px;
}

.loading-dots span {
  width: 6px;
  height: 6px;
  background: var(--accent);
  border-radius: 50%;
  animation: bounce 1.4s infinite ease-in-out both;
}

.loading-dots span:nth-child(1) { animation-delay: -0.32s; }
.loading-dots span:nth-child(2) { animation-delay: -0.16s; }

@keyframes bounce {
  0%, 80%, 100% { transform: scale(0); }
  40% { transform: scale(1); }
}

/* 输入区域 */
.input-container {
  padding: 16px 20px;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
}

.input-wrapper {
  max-width: 900px;
  margin: 0 auto;
  display: flex;
  gap: 12px;
  align-items: flex-end;
  width: 100%;
}

#messageInput {
  flex: 1;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px 16px;
  color: var(--text-primary);
  font-size: 14px;
  font-family: inherit;
  resize: none;
  max-height: 200px;
  outline: none;
  transition: border-color 0.2s;
}

#messageInput:focus {
  border-color: var(--accent);
}

.btn-send {
  width: 44px;
  height: 44px;
  background: var(--accent);
  border: none;
  border-radius: 12px;
  color: white;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.2s;
  flex-shrink: 0;
}

.btn-send:hover {
  background: var(--accent-hover);
}

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

.btn-icon {
  width: 36px;
  height: 36px;
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text-primary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s;
}

.btn-icon:hover {
  background: var(--bg-tertiary);
  border-color: var(--accent);
}

/* 流式输出样式 */
.message.streaming .message-content::after {
  content: '▋';
  animation: blink 1s infinite;
  margin-left: 2px;
}

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

.tool-indicator {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  margin-top: 8px;
  background: var(--bg-tertiary);
  border-radius: 6px;
  font-size: 12px;
  color: var(--text-secondary);
}

.tool-indicator .loading-dots {
  display: flex;
  gap: 3px;
}

.tool-indicator .loading-dots span {
  width: 4px;
  height: 4px;
  background: var(--accent);
  border-radius: 50%;
  animation: bounce 1.4s infinite ease-in-out both;
}

/* 移动端适配 */
@media (max-width: 768px) {
  .sidebar {
    position: fixed;
    left: 0;
    top: 0;
    height: 100vh;
    z-index: 1000;
    transform: translateX(-100%);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .menu-toggle {
    display: flex;
  }

  .header h1 {
    font-size: 16px;
  }

  .welcome-message {
    padding: 40px 20px;
  }

  .welcome-message h2 {
    font-size: 20px;
  }

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

  .message.user .message-content {
    margin-left: 20px;
  }

  .chat-container {
    padding: 16px;
  }
}

/* 滚动条样式 */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
  background: var(--bg-tertiary);
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--border);
}

/* Markdown 内容样式 */
.message-content h1,
.message-content h2,
.message-content h3,
.message-content h4 {
  margin: 1em 0 0.5em 0;
  font-weight: 600;
  line-height: 1.3;
}

.message-content h1 { font-size: 1.5em; }
.message-content h2 { font-size: 1.3em; }
.message-content h3 { font-size: 1.1em; }
.message-content h4 { font-size: 1em; }

.message-content p {
  margin: 0.5em 0;
  line-height: 1.6;
}

.message-content ul,
.message-content ol {
  margin: 0.5em 0;
  padding-left: 1.5em;
}

.message-content li {
  margin: 0.3em 0;
  line-height: 1.5;
}

.message-content blockquote {
  margin: 0.5em 0;
  padding: 0.5em 1em;
  border-left: 3px solid var(--accent);
  background: var(--bg-secondary);
  color: var(--text-secondary);
}

.message-content hr {
  margin: 1em 0;
  border: none;
  border-top: 1px solid var(--border);
}

/* 表格样式 */
.message-content table {
  width: 100%;
  margin: 1em 0;
  border-collapse: collapse;
  border: 1px solid var(--border);
  background: var(--bg-secondary);
  font-size: 0.9em;
}

.message-content table th,
.message-content table td {
  padding: 0.6em 1em;
  text-align: left;
  border: 1px solid var(--border);
}

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

.message-content table tr:hover {
  background: var(--bg-hover);
}

.message-content table td {
  color: var(--text-secondary);
}

/* 代码块样式优化 */
.message-content pre {
  margin: 1em 0;
  padding: 1em;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 6px;
  overflow-x: auto;
}

.message-content pre code {
  background: transparent;
  padding: 0;
  border: none;
  font-size: 0.9em;
  line-height: 1.5;
}

.message-content code {
  background: var(--bg-tertiary);
  padding: 0.2em 0.4em;
  border-radius: 3px;
  font-family: 'Monaco', 'Menlo', 'Consolas', monospace;
  font-size: 0.9em;
  color: var(--accent);
}

/* 链接样式 */
.message-content a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.2s;
}

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

/* 强调样式 */
.message-content strong {
  font-weight: 600;
  color: var(--text-primary);
}

.message-content em {
  font-style: italic;
  color: var(--text-secondary);
}