:root{
  --primary-color: #4361ee;
  --primary-light: #5a7af0;
  --primary-dark: #352ec0;
  --primary-gradient: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
  --bg-color: #f5f7fa;
  --chat-bg-color: #ffffff;
  --user-bubble-bg: var(--primary-gradient);
  --user-bubble-text: #ffffff;
  --ai-bubble-bg: #f8f9fc;
  --ai-bubble-text: #2d3748;
  --ai-bubble-border: #edf2f7;
  --input-bg: #ffffff;
  --input-border: #e2e8f0;
  --input-text: #2d3748;
  --footer-text: #718096;
  --footer-bg: #ffffff;
  --shadow-light: 0 2px 10px rgba(0,0,0,0.05);
  --shadow-medium: 0 4px 15px rgba(0,0,0,0.08);
  --shadow-soft: 0 8px 30px rgba(0,0,0,0.05);
  --border-radius-sm: 8px;
  --border-radius-md: 16px;
  --border-radius-lg: 24px;
  --border-radius-full: 9999px;
  --spacing-xs: 8px;
  --spacing-sm: 12px;
  --spacing-md: 16px;
  --spacing-lg: 20px;
  --app-width: 100%;
  --max-app-width: 600px;
  --avatar-size: 36px;
  --transition-default: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

@media (min-width: 600px) {
  :root {
    --app-width: 90%;
    --avatar-size: 40px;
  }
}

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

body{
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
  font-size: 16px;
  line-height: 1.7;
  background-color: var(--bg-color);
  color: var(--ai-bubble-text);
  display: flex;
  flex-direction: column;
  height: 100vh;
  overflow: hidden;
  margin: 0 auto;
  max-width: var(--max-app-width);
  width: var(--app-width);
  box-shadow: var(--shadow-soft);
  border-radius: 0 0 var(--border-radius-md) var(--border-radius-md);
}

/* 顶部导航 */
.header{
  background: var(--primary-gradient);
  color: #fff;
  padding: var(--spacing-md) var(--spacing-lg);
  text-align: center;
  font-size: 1.25rem;
  font-weight: 600;
  box-shadow: var(--shadow-medium);
  z-index: 10;
  flex-shrink: 0;
  position: relative;
  overflow: hidden;
  border-radius: 0 0 var(--border-radius-md) var(--border-radius-md);
}

.header::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.08'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");
  opacity: 0.8;
  mix-blend-mode: overlay;
}

/* 聊天容器 */
.chat-container{
  flex: 1;
  overflow-y: auto;
  padding: var(--spacing-lg) var(--spacing-md) var(--spacing-md);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-lg);
  background-color: var(--chat-bg-color);
  scroll-behavior: smooth;
}

.chat-container::-webkit-scrollbar{
  width: 5px;
}

.chat-container::-webkit-scrollbar-track{
  background-color: rgba(0,0,0,0.02);
  border-radius: var(--border-radius-full);
}

.chat-container::-webkit-scrollbar-thumb{
  background-color: rgba(156, 163, 175, 0.5);
  border-radius: var(--border-radius-full);
  transition: var(--transition-default);
}

.chat-container::-webkit-scrollbar-thumb:hover{
  background-color: rgba(156, 163, 175, 0.8);
}

/* 消息样式 */
.message-wrapper {
  display: flex;
  max-width: 100%;
}

.message {
  max-width: 85%;
  padding: var(--spacing-md) var(--spacing-lg);
  border-radius: var(--border-radius-lg);
  position: relative;
  font-size: 15px;
  white-space: pre-wrap;
  word-wrap: break-word;
  line-height: 1.6;
}

/* 用户消息 */
.user-message-wrapper {
  justify-content: flex-end;
}

.user-message {
  background: var(--user-bubble-bg);
  color: var(--user-bubble-text);
  border-bottom-right-radius: 6px;
  animation: slideInRight 0.3s ease-out;
  box-shadow: 0 2px 8px rgba(67, 97, 238, 0.15);
}

/* AI消息 */
.ai-message-wrapper {
  justify-content: flex-start;
  gap: var(--spacing-sm);
}

.ai-avatar {
  width: var(--avatar-size);
  height: var(--avatar-size);
  border-radius: 50%;
  flex-shrink: 0;
  margin-top: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-light);
  overflow: hidden;
  background-color: #f0f2f5;
}

.ai-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.ai-message {
  background: var(--ai-bubble-bg);
  color: var(--ai-bubble-text);
  border: 1px solid var(--ai-bubble-border);
  border-bottom-left-radius: 6px;
  animation: slideInLeft 0.3s ease-out;
}

/* 动画效果 */
@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* 示例问题容器 */
.example-links-container{
  align-self: center;
  background: var(--ai-bubble-bg);
  border: 1px solid var(--ai-bubble-border);
  color: var(--ai-bubble-text);
  padding: var(--spacing-lg) var(--spacing-md);
  border-radius: var(--border-radius-md);
  box-shadow: var(--shadow-light);
  font-size: 15px;
  text-align: center;
  max-width: 95%;
  animation: fadeIn 0.5s ease-out;
  width: 100%;
  margin-top: var(--spacing-md);
}

.example-links-container .greeting{
  margin-bottom: var(--spacing-md);
  font-weight: 500;
  color: var(--primary-dark);
  font-size: 14px;
  text-align: left;
}

.example-links-container a{
  display: inline-block;
  margin: 0 8px 10px;
  color: var(--primary-color);
  text-decoration: none;
  cursor: pointer;
  font-size: 0.95rem;
  padding: 8px 14px;
  border-radius: var(--border-radius-sm);
  transition: var(--transition-default);
  background-color: rgba(67, 97, 238, 0.05);
  border: 1px solid transparent;
}

.example-links-container a:hover{
  background-color: rgba(67, 97, 238, 0.1);
  text-decoration: none;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0,0,0,0.05);
  border-color: rgba(67, 97, 238, 0.15);
}

@media (max-width:768px){
  .example-links-container{
    padding: var(--spacing-md);
    max-width: calc(100% - 20px);
    margin: 0 10px var(--spacing-sm);
  }
  
  .example-links-container a{
    display: block;
    margin: 0 0 10px 0;
    padding: 10px 15px;
    font-size: 1rem;
    text-align: left;
  }
}

/* 输入区域 */
.input-area{
  display: flex;
  padding: var(--spacing-md);
  background-color: var(--footer-bg);
  border-top: 1px solid var(--ai-bubble-border);
  gap: var(--spacing-sm);
  flex-shrink: 0;
  box-shadow: 0 -2px 10px rgba(0,0,0,0.03);
}

#userInput{
  flex: 1;
  padding: var(--spacing-md);
  border: 1px solid var(--input-border);
  border-radius: var(--border-radius-full);
  outline: none;
  font-size: 16px;
  background-color: var(--input-bg);
  color: var(--input-text);
  box-shadow: var(--shadow-light);
  transition: var(--transition-default);
  resize: none;
  height: 52px;
  overflow-y: auto;
}

#userInput:focus{
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px rgba(67,97,238,0.15);
}

#sendButton{
  padding: 0 var(--spacing-lg);
  background: var(--primary-gradient);
  color: #fff;
  border: none;
  border-radius: var(--border-radius-full);
  cursor: pointer;
  font-size: 16px;
  font-weight: 500;
  transition: var(--transition-default);
  box-shadow: var(--shadow-light);
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 52px;
}

#sendButton:hover{
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(67,97,238,0.25);
}

#sendButton:active{
  transform: translateY(0);
  box-shadow: 0 2px 6px rgba(67,97,238,0.25);
}

#sendButton:disabled{
  background: #e2e8f0;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

/* 页脚 */
.footer{
  text-align: center;
  padding: var(--spacing-sm) var(--spacing-md);
  font-size: 0.85rem;
  color: var(--footer-text);
  background-color: var(--footer-bg);
  border-top: 1px solid var(--ai-bubble-border);
  flex-shrink: 0;
  line-height: 1.5;
  font-size: 10px;
}

/* 打字指示器 */
.typing-indicator-wrapper {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  align-self: flex-start;
}

.typing-indicator {
  background: var(--ai-bubble-bg);
  border: 1px solid var(--ai-bubble-border);
  color: var(--ai-bubble-text);
  padding: var(--spacing-md) var(--spacing-lg);
  border-radius: var(--border-radius-lg);
  border-bottom-left-radius: 6px;
  display: flex;
  font-size: 15px;
  box-shadow: var(--shadow-light);
  align-items: center;
  justify-content: flex-start;
}

.typing-indicator span{
  height: 10px;
  width: 10px;
  margin: 0 3px;
  background: var(--primary-color);
  display: inline-block;
  border-radius: 50%;
  opacity: 0.7;
  animation: typing 1.4s infinite ease-in-out;
}

.typing-indicator span:nth-of-type(1){
  animation-delay: -0.32s;
}

.typing-indicator span:nth-of-type(2){
  animation-delay: -0.16s;
}

@keyframes typing{
  0%, 80%, 100%{
    transform: scale(0.75);
    opacity: 0.4;
  }
  40%{
    transform: scale(1);
    opacity: 1;
  }
}

/* 响应式调整 */
@media (max-width: 480px) {
  .message {
    max-width: 80%;
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 14px;
  }
  
  .header {
    font-size: 1.1rem;
    padding: var(--spacing-sm) var(--spacing-md);
  }
  
  .chat-container {
    padding: var(--spacing-md) var(--spacing-xs);
    gap: var(--spacing-md);
  }
  
  .input-area {
    padding: var(--spacing-sm);
  }
  
  #userInput, #sendButton {
    height: 48px;
  }
  
  #sendButton {
    padding: 0 var(--spacing-md);
  }
}

/* 首次进入弹窗 */
.welcome-modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.3s ease, visibility 0.3s ease;
}

.welcome-modal.show {
  opacity: 1;
  visibility: visible;
}

.welcome-content {
  background-color: #fff;
  padding: 2rem;
  border-radius: var(--border-radius-md);
  max-width: 90%;
  width: 500px;
  text-align: center;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

.welcome-content h2 {
  color: var(--primary-color);
  margin-bottom: 1rem;
  font-size: 1.5rem;
}

.welcome-content p {
  margin-bottom: 1.5rem;
  line-height: 1.6;
  font-size: 1rem;
}

.welcome-content button {
  background: var(--primary-gradient);
  color: #fff;
  border: none;
  padding: 0.75rem 1.5rem;
  border-radius: var(--border-radius-full);
  cursor: pointer;
  font-size: 1rem;
  font-weight: 500;
  transition: var(--transition-default);
}

.welcome-content button:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(67, 97, 238, 0.25);
}

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