/* 全局样式重置 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

/* 现代化配色方案 */
:root {
  --primary-color: #3081D0;
  --primary-hover: #2C76BF;
  --bg-color: #FFFFFF;
  --bg-secondary: #F5F5F5;
  --text-primary: #1A1A1A;
  --text-secondary: #666666;
  --border-color: #E0E0E0;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.12);
  --transition: all 0.2s ease;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  line-height: 1.6;
  color: var(--text-primary);
  background-color: var(--bg-color);
  font-size: 14px;
}

/* 头部样式 */
header {
  background-color: var(--bg-color);
  border-bottom: 1px solid var(--border-color);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-left { display: flex; align-items: center; gap: 20px; }

.logo { margin-right: 0; }

.header-content {
  max-width: 1000px;
  margin: 0 auto;
  padding: 12px 20px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  display: flex;
  align-items: center;
  text-decoration: none;
  color: var(--text-primary);
  transition: var(--transition);
}

.logo:hover {
  opacity: 0.8;
}

.logo-image {
  height: 32px;
  width: 32px;
  margin-right: 10px;
  border-radius: 6px;
  object-fit: cover;
}

.logo-text {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  justify-content: center;
}

.logo-cn {
  font-size: 18px;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.2;
}

.logo-en {
  font-size: 11px;
  color: var(--text-secondary);
  font-weight: 400;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 12px;
}

.model-selector {
  position: relative;
}

.model-select {
  padding: 8px 36px 8px 12px;
  border: 1px solid var(--border-color);
  border-radius: 8px;
  background-color: var(--bg-color);
  color: var(--text-primary);
  font-size: 14px;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  -moz-appearance: none;
  transition: var(--transition);
  min-width: 120px;
}

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

.model-select:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(48, 129, 208, 0.1);
}

.model-select::after {
  content: '▼';
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 10px;
  color: var(--text-secondary);
  pointer-events: none;
}

.header-button {
  padding: 8px 16px;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  font-size: 14px;
  font-weight: 500;
  color: var(--text-primary);
  cursor: pointer;
  transition: var(--transition);
}

.header-button:hover {
  background-color: var(--border-color);
}

.header-button:active {
  transform: scale(0.98);
}

/* 主要内容区域 */
main {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0;
  min-height: calc(100vh - 140px);
}

/* 聊天窗口样式 */
.chat-container {
  display: flex;
  flex-direction: column;
  height: calc(100vh - 140px);
  background-color: var(--bg-color);
}

.chat-body {
  flex: 1;
  overflow-y: auto;
  padding: 40px 20px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.chat-body::-webkit-scrollbar {
  width: 6px;
}

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

.chat-body::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 3px;
}

.chat-body::-webkit-scrollbar-thumb:hover {
  background: var(--text-secondary);
}

/* 欢迎容器 */
.welcome-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 60px 20px;
  max-width: 600px;
  margin: 0 auto;
}

.welcome-icon {
  font-size: 64px;
  margin-bottom: 24px;
  opacity: 0.9;
}

.welcome-title {
  font-size: 32px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 12px;
  line-height: 1.3;
}

.welcome-text {
  font-size: 16px;
  color: var(--text-secondary);
  margin-bottom: 40px;
  line-height: 1.6;
}

/* 快捷操作 */
.quick-actions {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
  width: 100%;
  max-width: 500px;
}

.quick-action {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px 20px;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  cursor: pointer;
  transition: var(--transition);
  text-align: left;
  font-size: 14px;
  color: var(--text-primary);
  font-weight: 500;
}

.quick-action:hover {
  background-color: var(--bg-color);
  border-color: var(--primary-color);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.quick-action:active {
  transform: translateY(0);
}

.action-icon {
  font-size: 24px;
  flex-shrink: 0;
}

.action-text {
  flex: 1;
}

/* 消息样式 - 简化设计 */
.message {
  max-width: 75%;
  padding: 12px 0;
  word-wrap: break-word;
  line-height: 1.7;
  white-space: pre-wrap;
  font-size: 15px;
  position: relative;
}

.user-message {
  color: var(--text-primary);
  align-self: flex-end;
  background-color: var(--bg-secondary);
  border-radius: 12px;
  padding: 14px 18px;
}

.ai-message {
  color: var(--text-primary);
  align-self: flex-start;
  background-color: #f8f9fa;
  border-radius: 12px;
  padding: 14px 18px;
}

/* 聊天输入区域 */
.chat-footer {
  padding: 20px;
  border-top: 1px solid var(--border-color);
  background-color: var(--bg-color);
}

.chat-form {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.input-container {
  display: flex;
  gap: 12px;
  align-items: flex-end;
}

.input-wrapper {
  flex: 1;
  position: relative;
  display: flex;
  align-items: flex-end;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  transition: var(--transition);
}

.input-wrapper:focus-within {
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(48, 129, 208, 0.1);
}

.message-input {
  flex: 1;
  padding: 14px 16px;
  border: none;
  background: transparent;
  font-size: 15px;
  font-family: inherit;
  line-height: 1.5;
  resize: none;
  min-height: 52px;
  max-height: 200px;
  outline: none;
  color: var(--text-primary);
}

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

.input-actions {
  display: flex;
  gap: 8px;
  padding: 8px 12px;
  align-items: center;
}

.action-button {
  padding: 8px;
  background-color: transparent;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
}

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

.action-button:active {
  transform: scale(0.95);
}

.send-button {
  width: auto;
  min-width: 52px;
  height: 52px;
  background-color: var(--primary-color);
  color: white;
  border: none;
  border-radius: 12px;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 16px;
  flex-shrink: 0;
  box-shadow: var(--shadow-md);
}

.send-button:hover:not(:disabled) {
  background-color: var(--primary-hover);
  transform: scale(1.05);
  box-shadow: var(--shadow-lg);
}

.send-button:active:not(:disabled) {
  transform: scale(0.98);
}

.send-button:disabled {
  background-color: var(--border-color);
  color: var(--text-secondary);
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.send-button svg {
  width: 20px;
  height: 20px;
}

.button-text {
  margin-left: 6px;
  font-size: 14px;
  font-weight: 500;
  white-space: nowrap;
}

/* 页脚提示 */
.footer-hint {
  text-align: center;
  padding: 8px 0;
}

.hint-text {
  font-size: 12px;
  color: var(--text-secondary);
  opacity: 0.8;
}

/* 页脚样式 */
footer {
  background-color: var(--bg-color);
  border-top: 1px solid var(--border-color);
  padding: 16px 0;
}

.footer-content {
  max-width: 1000px;
  margin: 0 auto;
  padding: 0 20px;
  text-align: center;
}

.footer-text {
  color: var(--text-secondary);
  font-size: 13px;
  margin: 0;
}

/* 加载动画 */
.loading {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 2px solid var(--border-color);
  border-top: 2px solid var(--primary-color);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* 时间戳样式 */
.timestamp {
  font-size: 11px;
  opacity: 0.7;
  margin-top: 6px;
  text-align: right;
}

.user-message .timestamp {
  color: rgba(255, 255, 255, 0.8);
}

.ai-message .timestamp {
  color: var(--text-secondary);
}

/* 复制按钮样式 */
.copy-button {
  padding: 4px 12px;
  background-color: rgba(0, 0, 0, 0.05);
  border: none;
  border-radius: 4px;
  font-size: 12px;
  cursor: pointer;
  transition: var(--transition);
  margin-top: 8px;
  align-self: flex-end;
  color: var(--text-secondary);
}

.ai-message .copy-button {
  background-color: rgba(48, 129, 208, 0.1);
  color: var(--primary-color);
}

.copy-button:hover {
  background-color: rgba(0, 0, 0, 0.1);
}

.ai-message .copy-button:hover {
  background-color: rgba(48, 129, 208, 0.2);
}

/* 响应式设计 - 移动端优化 */
@media (max-width: 768px) {
  .header-left { display: flex; align-items: center; gap: 12px; }

  .logo { margin-right: 0; }

  .header-content {
    padding: 6px 10px;
    gap: 8px;
  }
  
  .logo-image {
    height: 22px;
    width: 22px;
  }
  
  .logo-cn {
    font-size: 13px;
  }
  
  .logo-en {
    display: none;
  }
  
  .model-select {
    min-width: 70px;
    max-width: 80px;
    padding: 5px 20px 5px 6px;
    font-size: 11px;
  }
  
  .header-button {
    padding: 5px 8px;
    font-size: 11px;
  }
  
  .chat-container {
    height: calc(100vh - 54px);
    display: flex;
    flex-direction: column;
    width: 100%;
    max-width: 100%;
  }
  
  .chat-body {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    padding: 12px 10px;
    gap: 12px;
    min-height: 0;
    display: flex;
    flex-direction: column;
    width: 100%;
  }
  
  .welcome-container {
    padding: 20px 10px;
  }
  
  .welcome-icon {
    font-size: 36px;
    margin-bottom: 10px;
  }
  
  .welcome-title {
    font-size: 18px;
    margin-bottom: 6px;
  }
  
  .welcome-text {
    font-size: 12px;
    margin-bottom: 16px;
  }
  
  .quick-actions {
    grid-template-columns: 1fr;
    max-width: 100%;
    gap: 8px;
  }
  
  .quick-action {
    padding: 10px 12px;
    font-size: 12px;
  }
  
  .action-icon {
    font-size: 16px;
  }
  
  .message {
    max-width: 90%;
    font-size: 14px;
    word-break: break-word;
    overflow-wrap: break-word;
  }
  
  .user-message {
    padding: 10px 14px;
  }
  
  .ai-message {
    padding: 10px 14px;
    background-color: #f8f9fa;
  }
  
  .chat-footer {
    padding: 10px;
    background-color: var(--bg-color);
    border-top: 1px solid var(--border-color);
    flex-shrink: 0;
    width: 100%;
  }
  
  .input-container {
    gap: 6px;
    align-items: flex-end;
    width: 100%;
  }
  
  .input-wrapper {
    border-radius: 10px;
  }
  
  .message-input {
    min-height: 40px;
    font-size: 14px;
    padding: 10px 12px;
  }
  
  .send-button {
    width: auto;
    min-width: 40px;
    height: 40px;
    padding: 0 10px;
    flex-shrink: 0;
    border-radius: 10px;
  }
  
  .button-text {
    font-size: 12px;
    margin-left: 4px;
  }
  
  .footer-text {
    font-size: 10px;
  }
}

@media (max-width: 480px) {
  .header-right {
    gap: 8px;
  }
  
  .model-select {
    min-width: 80px;
    padding: 6px 24px 6px 8px;
    font-size: 12px;
  }
  
  .header-button {
    padding: 6px 10px;
    font-size: 12px;
  }
  
  .quick-action {
    padding: 12px 14px;
    font-size: 13px;
  }
  
  .action-icon {
    font-size: 20px;
  }
}

/* AI-PPT链接样式 */
.ppt-link {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  text-decoration: none;
  font-size: 13px;
  cursor: pointer;
  transition: var(--transition);
}

.ppt-link:hover {
  background-color: var(--border-color);
  color: var(--primary-color);
}

.ppt-icon {
  font-size: 14px;
}

.ppt-text {
  font-size: 13px;
  font-weight: 500;
}

/* AI科创链接样式 */
.kc-link {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  text-decoration: none;
  font-size: 13px;
  cursor: pointer;
  transition: var(--transition);
}

.kc-link:hover {
  background-color: var(--border-color);
  color: var(--primary-color);
}

.kc-icon {
  font-size: 14px;
}

.kc-text {
  font-size: 13px;
  font-weight: 500;
}

/* AI工具页面样式 */
.tools-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 60px 20px;
}

.tools-header {
  text-align: center;
  margin-bottom: 40px;
}

.tools-title {
  font-size: 36px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 12px;
}

.tools-subtitle {
  font-size: 16px;
  color: var(--text-secondary);
  margin-bottom: 40px;
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.tool-card {
  display: flex;
  flex-direction: column;
  background-color: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: 16px;
  padding: 24px;
  transition: var(--transition);
  text-decoration: none;
  color: var(--text-primary);
}

.tool-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--primary-color);
}

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

.tool-content {
  flex: 1;
}

.tool-name {
  font-size: 20px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.tool-description {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 16px;
}

.tool-tags {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.tool-tag {
  padding: 4px 12px;
  background-color: var(--bg-secondary);
  border-radius: 6px;
  font-size: 12px;
  color: var(--text-secondary);
}

.back-button {
  padding: 8px 16px;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  font-size: 14px;
  cursor: pointer;
  transition: var(--transition);
  color: var(--text-primary);
}

.back-button:hover {
  background-color: var(--border-color);
  color: var(--primary-color);
}

/* AI工具页面响应式设计 */
@media (max-width: 768px) {
  .tools-container {
    padding: 40px 16px;
  }
  
  .tools-grid {
    grid-template-columns: 1fr;
  }
  
  .tool-card {
    padding: 20px;
  }
  
  .tools-title {
    font-size: 28px;
  }
  
  .tool-icon {
    font-size: 40px;
  }
}

/* 按钮组样式 */
.button-group {
  display: flex;
  gap: 8px;
  align-items: flex-end;
}

.chat-button {
  flex: 1;
}

.work-button {
  flex: 1;
  background-color: var(--bg-secondary);
  color: var(--text-secondary);
}

.work-button:not(:disabled) {
  color: var(--text-primary);
  cursor: pointer;
}

.work-button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* AI工具链接样式更新 */
.ppt-link {
  gap: 6px;
  padding: 6px 12px;
}

.ppt-icon {
  font-size: 16px;
}

.ppt-text {
  font-size: 14px;
}