:root {
  --primary-color: #2e7d32;
  --secondary-color: #ff9800;
  --light-color: #f8f9fa;
  --dark-color: #1b5e20;
  --accent-color: #4caf50;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Segoe UI', Arial, sans-serif;
}

body {
  line-height: 1.6;
  color: #333;
  background-color: #f5f5f5;
}

/* 顶部导航栏 */
.top-header {
  background-color: var(--primary-color);
  color: white;
  padding: 0.5rem 2rem;
  font-size: 0.9rem;
  text-align: center;
}

.navbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 2rem;
  background-color: white;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.logo-container {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.logo-image {
  height: 60px;
  width: auto;
  object-fit: contain;
}

.logo {
  font-size: 2.2rem;
  font-weight: bold;
  color: var(--primary-color);
 
}

.logo-subtitle {
  font-size: 2.2rem;
  color: #666;
  font-weight: bold;
}

/* 更新导航菜单样式 */
.nav-links {
  display: flex;
  list-style: none;
}

.nav-links > li {
  margin-left: 1.3rem;
  position: relative;
}

.nav-links a {
  text-decoration: none;
  color: var(--dark-color);
  font-weight: 600;
  text-transform: uppercase;
  font-size: 0.9rem;
  transition: all 0.3s;
  padding: 0.5rem 0;
  display: block;
}

.nav-links > li > a {
  font-weight: 700;
  font-size: 1rem;
  color: var(--primary-color);
  border-bottom: 2px solid transparent;
}

.nav-links > li > a:hover,
.nav-links > li > a.active {
  color: var(--secondary-color);
  border-bottom-color: var(--secondary-color);
}

/* 二级菜单样式 */
.sub-menu {
  position: absolute;
  top: 100%;
  left: 0;
  background-color: white;
  min-width: 200px;
  box-shadow: 0 5px 10px rgba(0,0,0,0.1);
  border-radius: 0 0 5px 5px;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s;
  z-index: 100;
}

.nav-links > li:hover .sub-menu {
  opacity: 1;
  visibility: visible;
}

.sub-menu li {
  padding: 0.1rem 0.2rem;
  border-bottom: 1px solid #eee;
  margin-left: 2rem;
}

.sub-menu li:last-child {
  border-bottom: none;
}

.sub-menu a {
  color: var(--dark-color);
  font-weight: 500;
  text-transform: none;
}

.sub-menu a:hover {
  color: var(--secondary-color);
}

/* 更新语言切换按钮样式 */
.language-switcher {
  display: flex;
  margin-left: 2rem;
}

.lang-btn {
  padding: 0.5rem 0.8rem;
  background: none;
  border: 1px solid var(--primary-color);
  color: var(--primary-color);
  cursor: pointer;
  font-size: 0.9rem;
  transition: all 0.3s ease;
  min-width: 60px;
  text-align: center;
}

.lang-btn:first-child {
  border-radius: 4px 0 0 4px;
  border-right: none;
}

.lang-btn:last-child {
  border-radius: 0 4px 4px 0;
}

.lang-btn.active {
  background-color: var(--primary-color);
  color: white;
}

.lang-btn:not(.active):hover {
  background-color: rgba(46, 125, 50, 0.1);
}

.hamburger {
  display: none;
  cursor: pointer;
  font-size: 2.4rem;
  line-height: 1;
  text-align: center;
  width: 1.5em;
  align-items: center;
  justify-content: center;
  align-self: center;
  margin-left: 1rem;
}

/* 添加关闭图标样式 */
.hamburger.close {
  font-size: 2.4rem;
  line-height: 1;
}

/* 主横幅 */
.hero {
  height: 360px;
  background-size: cover;
  background-position: center;
  color: white;
  padding: 2rem;
  text-align: center;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-content {
  position: relative;
  z-index: 2;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 1rem;
  box-sizing: border-box;
}

@keyframes slideshow {
  0%, 100% {
      background-image: url('../img/banner01.jpg');
  }
  33% {
      background-image: url('../img/banner02.jpg');
  }
  66% {
      background-image: url('../img/banner03.jpg');
  }
}

.hero h1 {
  font-size: 2.8rem;
  margin-bottom: 0.5rem;
  text-transform: uppercase;
}

.hero h1 sup {
  font-size: 1.2rem;
}

.hero-date {
  font-size: 1.7rem;
  margin-bottom: 2rem;
  font-weight: 300;
}

.hero-subtitle {
  font-size: 1.2rem;
  max-width: 800px;
  margin: 0 auto 2rem;
}

/* 主要内容区域 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding-left:2rem;
  padding-right:2rem;
}

.content-wrapper {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 2rem;
  margin: 3rem 0;
  align-items: start;
}

@media (min-width: 769px) {
  .content-wrapper {
      grid-template-areas: "main sidebar";
  }
}

@media (max-width: 768px) {
  .content-wrapper {
      grid-template-columns: 1fr;
      grid-template-areas: 
          "main";
  }
}

.content-area {
  grid-area: main;
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.sidebar {
  grid-area: sidebar;
  background: white;
  padding: 2rem;
  border-radius: 8px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.05);
  height: fit-content;
}

.sidebar-section {
  margin-bottom: 2rem;
}

.sidebar-section:last-child {
  margin-bottom: 0;
}

.content-card {
  background: white;
  padding: 2rem;
  border-radius: 8px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}

/* 移动端侧边栏内容默认隐藏 */
.mobile-sidebar-content {
  display: none;
}

@media (min-width: 769px) {
  .content-wrapper {
      grid-template-columns: 2fr 1fr;
  }
}

.content-area {
  display: flex;
  flex-direction: column;
  gap: 2rem;
}

.content-card {
  background: white;
  padding: 2rem;
  border-radius: 8px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.05);
}

.sidebar {
  background: white;
  padding: 2rem;
  border-radius: 8px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.05);
  height: fit-content;
}

.sidebar-section {
  margin-bottom: 2rem;
}

.sidebar-section:last-child {
  margin-bottom: 0;
}

.section-title {
  color: var(--primary-color);
  border-bottom: 2px solid var(--secondary-color);
  padding-bottom: 0.5rem;
  margin-bottom: 1.5rem;
  font-size: 1.5rem;
}

/* 按钮样式 */
.button-group {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin: 2rem 0;
  justify-content: center;
  width: 100%;
}

.btn {
  display: inline-block;
  padding: 0.8rem 1.5rem;
  background-color: var(--secondary-color);
  color: white;
  text-decoration: none;
  border-radius: 4px;
  font-weight: 600;
  text-align: center;
  transition: background-color 0.3s;
  border: none;
  cursor: pointer;
}

.btn:hover {
  background-color: #e67e22;
}

.btn-primary {
  background-color: var(--primary-color);
}

.btn-primary:hover {
  background-color: #154360;
}

.btn-secondary {
  background-color: var(--accent-color);
}

.btn-secondary:hover {
  background-color: #239b56;
}

/* 关键日期 */
.key-dates {
  margin-top: 0.1rem;
}

.date-item {
  padding: 0.2rem 0;
  border-bottom: 1px solid #eee;
}

.date-item:last-child {
  border-bottom: none;
}

.date-title {
  font-weight: 600;
  color: var(--primary-color);
}

/* 会议日程表格 */
.schedule-table {
  width: 100%;
  border-collapse: collapse;
  margin: 1.5rem 0;
}

.schedule-table th, .schedule-table td {
  padding: 0.8rem;
  text-align: left;
  border-bottom: 1px solid #eee;
}

.schedule-table th {
  background-color: #f5f5f5;
  color: var(--primary-color);
  font-weight: 600;
}

.schedule-table tr:hover {
  background-color: #f9f9f9;
}

/* 页脚 */
footer {
  background-color: var(--dark-color);
  color: white;
  padding: 3rem 2rem 1rem;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
}

.footer-section h3 {
  color: var(--secondary-color);
  margin-bottom: 1rem;
  font-size: 1.2rem;
}

.contact-info {
  line-height: 1.8;
}

.copyright {
  text-align: center;
  padding-top: 2rem;
  margin-top: 2rem;
  border-top: 1px solid rgba(255,255,255,0.1);
  font-size: 0.9rem;
  color: #aaa;
}

/* 响应式设计 */
@media (max-width: 768px) {
  .logo-container {
    gap: 0.2rem;
  }

  .logo-image {
    display: none;
  }

  .logo {
    font-size: 1.4rem;
  }

  .logo-subtitle {
    font-size: 1.4rem;
  }
  
  .hero {
      height: 250px;
      padding: 2rem 1rem;
  }
  
  .hero h1 {
      font-size: 1.4rem;
  }
    
  .hero h1 sup {
    font-size: 0.7rem;
  }

  .hero-date {
      font-size: 1.1rem;
  }
  
  .hero-subtitle {
      font-size: 1rem;
       
  }
  
  .navbar {
      padding: 1rem;
  }
  
  .nav-links {
      display: none;
      flex-direction: column;
      width: 100%;
      position: fixed;
      top: 70px;
      left: 0;
      right: 0;
      bottom: 0;
      background-color: white;
      padding: 1rem;
      box-shadow: 0 5px 10px rgba(0,0,0,0.1);
      overflow-y: auto;
      height: calc(100vh - 70px);
      z-index: 1000;
  }
  
  .nav-links.active {
      display: flex;
  }
  
  .nav-links > li {
      margin: 0.1rem 0;
  }
  
  .nav-links > li > a {
      font-size: 0.9rem;
      padding: 0.2rem 0;
  }
  
  .has-submenu > a::after {
      float: right;
      margin-top: 5px;
  }
  
  .sub-menu {
      position: static;
      opacity: 1;
      visibility: visible;
      box-shadow: none;
      margin-top: 0.5rem;
      padding-left: 1rem;
  }
  
  .language-switcher {
      margin-left: 1rem;
  }
  
  .lang-btn {
      padding: 0.4rem 0.6rem;
      font-size: 0.8rem;
      min-width: 50px;
  }
  
  .hamburger {
      display: block;
  }
  
  .content-wrapper {
      grid-template-columns: 1fr;
      gap: 2rem;
  }
  
  .content-area {
      gap: 2rem;
      display: flex;
      flex-direction: column;
  }
  
  /* 隐藏PC端侧边栏 */
  .sidebar {
      display: none;
  }
  
  /* 显示移动端专用内容 */
  .mobile-sidebar-content {
      display: block;
  }
  
  /* 确保移动端Quick Links按钮文字为白色且无下划线 */
  .mobile-sidebar-content .btn {
      color: white;
      text-decoration: none;
      font-weight: bold;
  }
  
  /* 确保移动端Quick Links按钮悬停时文字仍为白色且无下划线 */
  .mobile-sidebar-content .btn:hover {
      color: white;
      text-decoration: none;
  }
  
  .button-group {
      flex-direction: column;
      gap: 0.5rem;
      margin: 1rem 0;
  }
  
  .btn {
      padding: 0.8rem 1.5rem; /* 与PC端保持一致 */
      font-size: 0.9rem;
      width: 100%;
      display: inline-block;
  }
  
  .schedule-table {
      font-size: 0.9rem;
  }
  
  .hero-subtitle {
     
  }
}

@media (max-width: 480px) {
  .logo {
    font-size: 1.2rem;
  }

  .logo-subtitle {
    font-size: 1.2rem;
  }
  
  .container, .navbar {
      padding-left: 1rem;
      padding-right: 1rem;
  }
  
  .hero {
      padding: 1rem;
      height: 250px;
  }
  
  .hero h1 {
      font-size: 1.3rem;
      margin-top: 0;
      margin-bottom: 0.3rem;
  }
  
  .hero-date {
      font-size: 0.9rem;
  }
  
  .hero-subtitle {
      font-size: 0.8rem;
     
  }
  
  .button-group {
      gap: 0.4rem;
      margin: 0.5rem 0;
  }
  
  .btn {
      padding: 0.4rem 0.6rem;
      font-size: 0.8rem;
      width: auto;
      display: inline-block;
  }
  
  .content-card, .sidebar {
      padding: 1.5rem;
  }
}

/* 辅助类 */
.highlight {
  background-color: #fff9e6;
  padding: 1.5rem;
  border-radius: 5px;
  margin: 1.5rem 0;
  border-left: 4px solid var(--secondary-color);
}

/* Organizers卡片中超链接的样式 */
.content-card a {
  color: #1d1e1e; /* 更好看的默认链接颜色 */
  text-decoration: none;
  transition: color 0.3s ease;
  font-weight: 400;
}

.content-card a:hover {
  color: var(--accent-color); /* 悬停时变为绿色 */
  text-decoration: underline;
}

/* Organizers卡片中图片链接的特殊样式 */
.content-card a img {
  transition: all 0.3s ease;
  border-radius: 4px;
  box-shadow: 0 2px 5px rgba(0,0,0,0.1);
}

.content-card a:hover img {
  transform: translateY(-5px);
  box-shadow: 0 8px 15px rgba(0,0,0,0.2);
  filter: brightness(1.05);
}

/* 专门针对Organizers卡片中的机构链接样式 */
#organizers a {
  color: #1976d2; /* 保持默认链接颜色 */
  text-decoration: none;
  transition: color 0.3s ease;
  font-weight: 400;
}

#organizers a:hover {
  color: var(--accent-color); /* 悬停时变为绿色 */
  text-decoration: underline;
}

/* 移动端专用内容（桌面端） */
.mobile-sidebar-content {
  display: none;
}

.text-center {
  text-align: center;
}

.mt-2 { margin-top: 2rem; }
.mt-3 { margin-top: 3rem; }
.mb-2 { margin-bottom: 2rem; }

/* 下拉菜单指示器 */
.has-submenu > a::after {
  content: " \25BC";
  font-size: 0.7em;
  vertical-align: middle;
  margin-left: 5px;
}

@media (min-width: 769px) {
  .has-submenu > a::after {
      float: right;
      margin-top: 5px;
  }
}