:root {
  --color-bg: #ffffff;
  --color-surface: #f7f8fa;
  --color-text: #0f172a;
  --color-muted: #64748b;
  --color-border: #e5e7eb;
  --color-primary: #2563eb;
  --color-primary-contrast: #ffffff;

  --radius-md: 12px;
  --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 4px 16px rgba(15, 23, 42, 0.08);

  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-6: 24px;
  --space-8: 32px;
  --space-12: 48px;
  --space-16: 64px;
  --space-20: 80px;

  --container-max: 960px;
  
  /* Animation variables */
  --reveal-distance: 40px;
  --reveal-duration: 0.8s;
  --reveal-stagger: 0.12s;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0b1220;
    --color-surface: #0f172a;
    --color-text: #e5e7eb;
    --color-muted: #94a3b8;
    --color-border: #1f2937;
    --shadow-sm: 0 2px 10px rgba(0, 0, 0, 0.4);
    --shadow-md: 0 4px 20px rgba(0, 0, 0, 0.5);
  }
}

*,
*::before,
*::after { 
  box-sizing: border-box; 
}

html { 
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
	margin: 0;
  color: var(--color-text);
  background: var(--color-bg);
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Noto Sans, PingFang SC, Hiragino Sans GB, Microsoft YaHei, sans-serif;
  line-height: 1.65;
  font-size: 16px;
  overflow-x: hidden;
}

img, video { 
  max-width: 100%; 
  height: auto; 
  display: block; 
}

/* ==================== Container ==================== */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-4);
}

/* Full-width hero on desktop */
@media (min-width: 768px) {
  .hero {
    margin-left: calc(-50vw + 50%);
    margin-right: calc(-50vw + 50%);
    width: 100vw;
    padding-left: var(--space-6);
    padding-right: var(--space-6);
  }
}

@media (min-width: 1024px) {
  .hero {
    padding-left: var(--space-8);
    padding-right: var(--space-8);
  }
}

/* ==================== Header & Navigation ==================== */
.header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.85);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: saturate(180%) blur(20px);
  transition: background 0.3s ease, box-shadow 0.3s ease;
}

.header.scrolled {
  background: rgba(255, 255, 255, 0.95);
  box-shadow: var(--shadow-sm);
}

@media (prefers-color-scheme: dark) {
  .header {
    background: rgba(11, 18, 32, 0.85);
  }
  .header.scrolled {
    background: rgba(11, 18, 32, 0.95);
  }
}

/* Support for original header structure */
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
  padding: var(--space-3) 0;
  gap: var(--space-4);
}

.brand {
  display: flex;
  align-items: center;
  text-decoration: none;
  transition: opacity 0.2s ease;
}

.brand:hover {
  opacity: 0.8;
}

.brand img {
  height: 48px;
  width: auto;
}

.header nav {
  display: none;
  align-items: center;
}

@media (min-width: 768px) {
  .header nav {
    display: flex;
  }
}

.header nav ul {
  display: flex;
  list-style: none;
  margin: 0;
    padding: 0;
  gap: var(--space-2);
  align-items: center;
}

.header nav ul li {
  margin: 0;
}

.header nav ul li a {
  color: var(--color-text);
  text-decoration: none;
  padding: 8px 12px;
  border-radius: 8px;
  transition: background 0.2s ease, color 0.2s ease;
  font-size: 15px;
  display: block;
}

.header nav ul li a:hover {
  background: var(--color-surface);
  color: var(--color-primary);
}

.navbar {
    display: flex;
    align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: var(--space-4);
}

.logo {
  font-size: 20px;
  font-weight: 700;
  text-decoration: none;
  color: var(--color-text);
  transition: opacity 0.2s ease;
}

.logo:hover {
  opacity: 0.7;
}

.nav-links {
  display: none;
  gap: var(--space-4);
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav-links a {
  color: var(--color-text);
  text-decoration: none;
  padding: 8px 12px;
    border-radius: 8px;
  transition: background 0.2s ease, color 0.2s ease;
  font-size: 15px;
}

.nav-links a:hover {
  background: var(--color-surface);
  color: var(--color-primary);
}

.nav-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 10px;
  border: 1px solid var(--color-border);
  background: transparent;
  cursor: pointer;
  transition: background 0.2s ease, transform 0.2s ease;
}

.nav-toggle:hover {
  background: var(--color-surface);
}

.nav-toggle:active {
  transform: scale(0.95);
}

/* Hide nav toggle on desktop */
@media (min-width: 768px) {
  .nav-toggle {
    display: none;
  }
}

/* Language switcher */
.lang-switcher {
  display: inline-flex;
  gap: var(--space-2);
  padding: 4px;
  background: transparent;
  border-radius: 10px;
}

.lang-switcher a {
  padding: 6px 12px;
  border-radius: 8px;
  text-decoration: none;
  color: var(--color-muted);
  font-size: 14px;
  transition: all 0.2s ease;
}

.lang-switcher a.active {
  background: var(--color-primary);
  color: var(--color-primary-contrast);
}

/* ==================== Hero Section ==================== */
.hero {
  position: relative; 
  overflow: visible;
  padding: 60px 0 40px;
    background: transparent;
}

/* Support for grid-based hero layout */
.hero .grid {
  display: flex;
  flex-direction: column;
  gap: var(--space-8);
}

@media (min-width: 768px) {
  .hero .grid {
    max-width: 100%;
    margin: 0;
  }
  
  .hero .grid > div:first-child {
    display: flex;
    flex-direction: column;
    justify-content: center;
    text-align: left;
    max-width: 800px;
    margin: 0 auto;
}

  .hero .grid > div:last-child {
    width: 100vw;
    margin-left: calc(-50vw + 50%);
    margin-right: calc(-50vw + 50%);
    max-width: none;
  }
}

.hero-content {
  max-width: 600px;
  margin: 0 auto;
    text-align: center;
}

.hero h1 {
  font-size: clamp(28px, 6vw, 42px);
  line-height: 1.2;
  margin: 0 0 var(--space-4);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.hero p {
  color: var(--color-muted);
  margin: 0 0 var(--space-8);
  font-size: clamp(16px, 3vw, 18px);
  line-height: 1.7;
}

.hero-actions {
  display: flex;
  gap: var(--space-3);
  justify-content: center;
  flex-wrap: wrap;
}

/* Support for original hero styles */
.brand-title {
  font-size: 3.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 25%, #f093fb 50%, #f5576c 75%, #4facfe 100%);
  background-size: 300% 300%;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  text-transform: none;
  letter-spacing: normal;
  margin-bottom: var(--space-4);
  line-height: 1.1;
  animation: gradient-shift 3s ease-in-out infinite;
}

.gradient-text {
  background: linear-gradient(135deg, var(--color-text), var(--color-primary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.subhead {
  font-size: clamp(16px, 3vw, 18px);
  line-height: 1.7;
  color: var(--color-muted);
}

.mt-6 {
  margin-top: var(--space-6);
}

/* ==================== Buttons ==================== */
.btn {
  display: inline-flex;
    align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 14px 24px;
  border-radius: 12px;
  border: 1px solid transparent;
  font-weight: 600;
  text-decoration: none;
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease, color 160ms ease;
  cursor: pointer;
  font-size: 16px;
  min-height: 44px;
  white-space: nowrap;
}

.btn:active { 
  transform: scale(0.95); /* 更明显的点击反馈 */
  transition: all 0.1s ease; /* 快速响应 */
}

.btn-primary {
  background: var(--color-primary);
  color: var(--color-primary-contrast);
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.btn-ghost {
  background: transparent;
  color: var(--color-text);
  border-color: var(--color-border);
}

.btn-ghost:hover {
  background: var(--color-surface);
}

.btn-outline {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.btn-outline:hover {
  background: var(--color-surface);
  color: var(--color-primary);
  border-color: var(--color-primary);
}

/* ==================== Sections ==================== */
.section {
  padding: 32px 0; /* 减少section上下间距 */
}

/* 减少section间距，特别是title和内容之间 */
.section-title {
  margin-bottom: var(--space-2); /* 进一步减少标题下方间距 */
}

.section-content {
  margin-top: var(--space-2); /* 进一步减少内容上方间距 */
}

/* 减少网格间距 */
.grid {
  gap: var(--space-3); /* 减少网格间距 */
}

.grid.cols-2 {
  gap: var(--space-4); /* 减少两列网格间距 */
}

.grid.cols-3 {
  gap: var(--space-3); /* 减少三列网格间距 */
}

/* 团队页面特殊间距优化 */
#team-overview,
#cofounders,
#committee {
  padding: 24px 0; /* 团队页面更小的间距 */
}

#team-overview .section-title,
#cofounders .section-title,
#committee .section-title {
  margin-bottom: var(--space-2); /* 团队页面标题间距 */
}

/* 移动端进一步减少间距 */
@media (max-width: 767px) {
  .section {
    padding: 16px 0; /* 移动端更小的间距 */
  }
  
  /* 团队页面移动端间距 */
  #team-overview,
  #cofounders,
  #committee {
    padding: 16px 0;
  }
  
  .section-title {
    margin-bottom: var(--space-1); /* 移动端最小间距 */
  }
  
  .section-content {
    margin-top: var(--space-1); /* 移动端最小间距 */
  }
  
  .grid {
    gap: var(--space-2); /* 移动端网格间距更小 */
  }
  
  .grid.cols-2 {
    gap: var(--space-3); /* 移动端两列间距 */
  }
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-8);
  max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.section-title {
  font-size: clamp(24px, 4.5vw, 32px);
  margin: 0 0 var(--space-3);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.section-subtitle {
  color: var(--color-muted);
  font-size: clamp(15px, 3vw, 17px);
  margin: 0;
  line-height: 1.7;
}

/* Support for original section styles */
.section-content {
  max-width: 800px;
    margin: 0 auto;
}

.section-content p {
  margin-bottom: var(--space-3); /* 减少段落间距 */
  line-height: 1.7;
}

.en-title {
  font-size: 14px;
  color: var(--color-muted);
    font-weight: 500;
  margin-top: var(--space-2);
}

.achievement-list {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
  margin-top: var(--space-6);
}

@media (min-width: 768px) {
  .achievement-list {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* ==================== Grid System ==================== */
.grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-4);
}

/* Support for original grid classes */
.grid.cols-2 {
  grid-template-columns: 1fr;
  gap: var(--space-6);
  align-items: start;
}

.grid.cols-3 {
  grid-template-columns: 1fr;
  gap: var(--space-4);
}

@media (min-width: 640px) {
  .grid-2 { grid-template-columns: repeat(2, 1fr); }
  .grid.cols-2 { grid-template-columns: repeat(2, 1fr); }
  .grid.cols-3 { grid-template-columns: repeat(2, 1fr); }
}

@media (min-width: 768px) {
  .grid { grid-template-columns: repeat(2, 1fr); }
  .grid-3 { grid-template-columns: repeat(3, 1fr); }
  .grid.cols-2 { 
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-8);
  }
  .grid.cols-3 { grid-template-columns: repeat(3, 1fr); }
}

/* ==================== Cards ==================== */
.card {
  background: rgba(255, 255, 255, 0.8); /* 半透明白色背景 */
  border: 1px solid rgba(0, 0, 0, 0.08); /* 淡边框 */
  border-radius: 16px; /* 更圆润的边角 */
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.04); /* 轻微阴影 */
  overflow: hidden;
  transition: all 0.3s ease;
  height: 100%;
  display: flex;
  flex-direction: column;
  backdrop-filter: blur(10px); /* 毛玻璃效果 */
  position: relative;
  padding: var(--space-5); /* 增加卡片内部间距 */
}

/* 卡片渐变背景效果 */
.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(59, 130, 246, 0.1), transparent);
  transition: left 0.5s ease;
  z-index: 1;
}

/* 卡片悬停效果 - 桌面端 */
@media (min-width: 768px) {
  .card:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.12);
    border-color: rgba(59, 130, 246, 0.2);
  }

  .card:hover::before {
    left: 100%;
  }
}

/* 移动端触摸反馈效果 */
@media (max-width: 767px) {
  .card:active {
    transform: translateY(-4px) scale(0.98);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
    border-color: rgba(59, 130, 246, 0.3);
    background: rgba(255, 255, 255, 0.95);
  }
  
  .card:active::before {
    left: 100%;
  }
}

/* 团队照片在移动端的大小控制 */
@media (max-width: 767px) {
.card .grid.cols-2 img {
    width: 80px; /* 移动端照片宽度 */
    height: 80px; /* 移动端照片高度 */
    object-fit: cover;
    border-radius: 50%; /* 圆形头像 */
    flex-shrink: 0;
  }
  
  .card .grid.cols-2 {
    gap: var(--space-4); /* 增加照片和文字间距 */
    align-items: flex-start;
  }
}

/* 团队卡片照片和文字间距优化 */
.card .grid.cols-2 {
  gap: var(--space-4); /* 桌面端也增加间距 */
  align-items: flex-start;
}

.card .grid.cols-2 img {
  margin-right: var(--space-2); /* 照片右边距 */
}


/* 卡片点击反馈效果 */
.card:active {
  transform: translateY(-2px) scale(0.97); /* 点击时更明显的缩放 */
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06); /* 点击时阴影减弱 */
  transition: all 0.1s ease; /* 快速响应 */
  background: rgba(255, 255, 255, 0.9); /* 点击时背景稍微变亮 */
}

.card:active .card-media {
  transform: scale(1.03); /* 点击时图片轻微放大 */
}

/* 为卡片添加点击时的边框效果 */
.card:active {
  border-color: rgba(59, 130, 246, 0.3); /* 点击时边框变蓝 */
}

/* JavaScript触发的点击反馈效果 */
.card.clicked,
.event-card.clicked {
  transform: translateY(-2px) scale(0.97) !important;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06) !important;
  background: rgba(255, 255, 255, 0.9) !important;
  border-color: rgba(59, 130, 246, 0.3) !important;
  transition: all 0.1s ease !important;
}

.card.clicked .card-media,
.event-card.clicked .event-cover img {
  transform: scale(1.03) !important;
}

/* 活动卡片样式 */
.event-card {
  background: rgba(255, 255, 255, 0.8); /* 半透明白色背景 */
  border: 1px solid rgba(0, 0, 0, 0.08); /* 淡边框 */
  border-radius: 16px; /* 更圆润的边角 */
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.04); /* 轻微阴影 */
  overflow: hidden;
  transition: all 0.3s ease;
  height: 100%;
  display: flex;
  flex-direction: column;
  backdrop-filter: blur(10px); /* 毛玻璃效果 */
}

/* 活动卡片悬停效果 - 桌面端 */
@media (min-width: 768px) {
  .event-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.12);
    border-color: rgba(59, 130, 246, 0.2);
  }
}

/* 活动卡片移动端触摸反馈效果 */
@media (max-width: 767px) {
  .event-card:active {
    transform: translateY(-4px) scale(0.98);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
    border-color: rgba(59, 130, 246, 0.3);
    background: rgba(255, 255, 255, 0.95);
  }
}

/* 活动卡片点击反馈效果 */
.event-card:active {
  transform: translateY(-2px) scale(0.97); /* 点击时更明显的缩放 */
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06); /* 点击时阴影减弱 */
  transition: all 0.1s ease; /* 快速响应 */
  background: rgba(255, 255, 255, 0.9); /* 点击时背景稍微变亮 */
  border-color: rgba(59, 130, 246, 0.3); /* 点击时边框变蓝 */
}

.event-card:active .event-cover img {
  transform: scale(1.03); /* 点击时图片轻微放大 */
}

.event-cover {
    width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
}

.event-cover img {
  width: 100%;
  height: 100%;
    object-fit: cover;
  transition: transform 0.3s ease;
}

/* 活动卡片图片悬停效果 - 桌面端 */
@media (min-width: 768px) {
  .event-card:hover .event-cover img {
    transform: scale(1.05);
  }
}

/* 活动卡片图片移动端触摸反馈效果 */
@media (max-width: 767px) {
  .event-card:active .event-cover img {
    transform: scale(1.02);
  }
}

.event-content {
  padding: var(--space-4);
  flex: 1;
  display: flex;
  flex-direction: column;
}

.event-meta {
  display: flex;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
  font-size: 14px;
  color: var(--color-muted);
}

.event-title {
  font-size: 20px;
  font-weight: 700;
  line-height: 1.3;
  color: var(--color-text);
  margin: 0 0 var(--space-3);
}

.event-tags {
  display: flex;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
}

.tag {
  background: rgba(59, 130, 246, 0.1);
  color: var(--color-primary);
  padding: 4px 8px;
  border-radius: 12px;
  font-size: 12px;
  font-weight: 500;
}

.event-excerpt {
  color: var(--color-text);
  font-size: 16px;
  line-height: 1.6;
  margin: 0 0 var(--space-4);
  flex: 1;
  opacity: 0.8;
}

.card-media {
    width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  transition: transform 0.4s ease;
}

.card:hover .card-media {
  transform: scale(1.05);
}

.card-body { 
  padding: var(--space-4); /* 增加卡片内部间距 */
  flex: 1;
  display: flex;
  flex-direction: column;
  position: relative;
  z-index: 2;
}

/* 二维码卡片特殊样式 */
.card img {
  transition: transform 0.3s ease;
    border-radius: 8px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
  background: white;
  padding: var(--space-2);
}

/* 二维码卡片标题样式 */
.card .card-title {
  color: var(--color-primary);
  font-weight: 600;
  margin-bottom: var(--space-2);
}

/* 二维码卡片描述样式 */
.card .text-muted {
  color: var(--color-muted);
  font-size: 14px;
  font-weight: 500;
}

/* 二维码卡片悬停效果 - 桌面端 */
@media (min-width: 768px) {
  .card:hover img {
    transform: scale(1.05);
  }
}

/* 二维码卡片移动端触摸反馈效果 */
@media (max-width: 767px) {
  .card:active img {
    transform: scale(1.02);
  }
}

/* 联系方式样式 */
.contact-info {
  margin-top: var(--space-4);
}

.contact-info h3 {
  color: var(--color-primary);
  font-size: 18px;
  font-weight: 600;
  margin: var(--space-4) 0 var(--space-2) 0;
}

.contact-info h3:first-child {
  margin-top: 0;
}

.contact-info p {
  margin: var(--space-1) 0;
  line-height: 1.6;
}

.contact-info a {
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 500;
  transition: color 0.3s ease;
}

.contact-info a:hover {
  color: var(--color-accent);
  text-decoration: underline;
}

/* 联系我们页面section间距调整 */
.contact-page .section {
  padding: 24px 0; /* 减少section上下间距 */
}

.contact-page .section:first-child {
  padding-top: 16px; /* 第一个section顶部间距更小 */
}

.contact-page .section:last-child {
  padding-bottom: 16px; /* 最后一个section底部间距更小 */
}

/* 服务页面卡片内容左边距 */

.card h2,
.card h3 {
  margin-left: var(--space-2); /* 标题左边距 */
  position: relative;
  z-index: 2;
  transition: all 0.3s ease;
}

.card p {
  margin-left: var(--space-2); /* 段落左边距 */
  position: relative;
  z-index: 2;
  transition: all 0.3s ease;
}

.card ul {
  margin-left: var(--space-3); /* 列表左边距 */
  padding-left: var(--space-2); /* 列表项左边距 */
  position: relative;
  z-index: 2;
}

.card ul li {
  transition: all 0.3s ease;
}

/* 团队卡片特殊悬停效果 */
.card .grid.cols-2 img {
  transition: transform 0.3s ease;
}

.card:hover .grid.cols-2 img {
  transform: scale(1.05) !important;
}

/* 团队卡片文字悬停效果 */
.card:hover h3 {
  color: var(--color-primary) !important;
  transition: color 0.3s ease !important;
}

.card:hover p {
  color: var(--color-text) !important;
  opacity: 0.9 !important;
  transition: all 0.3s ease !important;
}

/* 服务卡片悬停效果 */
.card:hover h2,
.card:hover h3 {
  color: var(--color-primary) !important;
  transform: translateX(4px) !important;
  transition: all 0.3s ease !important;
}

.card:hover ul li {
  color: var(--color-primary) !important;
  transform: translateX(4px) !important;
  transition: all 0.3s ease !important;
}

.card:hover ul li:nth-child(1) {
  transition-delay: 0.1s;
}

.card:hover ul li:nth-child(2) {
  transition-delay: 0.2s;
}

.card:hover ul li:nth-child(3) {
  transition-delay: 0.3s;
}

.card:hover ul li:nth-child(4) {
  transition-delay: 0.4s;
}

.card-title {
  margin: 0 0 var(--space-3);
  font-size: 20px; /* 增大标题字体 */
  font-weight: 700; /* 更粗的字体 */
  line-height: 1.3;
  color: var(--color-text);
}

.card-meta {
  color: var(--color-muted);
  font-size: 14px;
  margin-bottom: var(--space-3);
}

.card-description {
  color: var(--color-text);
  font-size: 16px; /* 增大描述字体 */
  line-height: 1.6;
  margin: 0 0 var(--space-4);
  flex: 1;
  opacity: 0.8; /* 稍微透明 */
}

.card-link {
  color: var(--color-primary);
  text-decoration: none;
  font-size: 15px;
  font-weight: 600;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  transition: gap 0.2s ease;
}

.card-link:hover {
  gap: 8px;
}

/* ==================== Forms ==================== */
.input, .textarea, .select {
    width: 100%;
  padding: 14px 16px;
  border-radius: 12px;
  border: 1px solid var(--color-border);
  background: var(--color-bg);
  color: var(--color-text);
  font-size: 16px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.input:focus, .textarea:focus, .select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.textarea { 
  min-height: 140px; 
  resize: vertical;
  line-height: 1.6;
  font-family: inherit;
}

.form-row { 
  display: grid; 
  gap: var(--space-4);
  margin-bottom: var(--space-4);
}

.form-label {
    display: block;
  margin-bottom: var(--space-2);
  font-weight: 600;
  font-size: 15px;
}

/* ==================== Footer ==================== */
.footer {
  border-top: 1px solid var(--color-border);
  padding: 32px 0 48px;
  color: var(--color-muted);
  font-size: 14px;
  margin-top: var(--space-12);
}

.footer-content {
  display: grid;
  gap: var(--space-6);
  text-align: center;
}

/* Support for original footer structure */
.footer-grid {
  display: grid;
        grid-template-columns: 1fr;
  gap: var(--space-6);
  margin-bottom: var(--space-4);
}

.footer-grid section h3 {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-text);
  margin: 0 0 var(--space-3);
}

.footer-grid section p {
  margin: 0;
  line-height: 1.6;
}

.footer-grid a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color 0.2s ease;
}

.footer-grid a:hover {
  color: var(--color-text);
}

.bottom-strip {
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-border);
        text-align: center;
    }
    
@media (min-width: 768px) {
  .footer-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}
    
/* ==================== Tech Animations ==================== */

/* 科技感背景动画 */
@keyframes tech-bg {
  0% { transform: translateX(-100%); }
  100% { transform: translateX(100%); }
}

@keyframes float {
  0%, 100% { transform: translateY(0px); }
  50% { transform: translateY(-10px); }
}

@keyframes pulse-glow {
  0%, 100% { box-shadow: 0 0 20px rgba(59, 130, 246, 0.3); }
  50% { box-shadow: 0 0 40px rgba(59, 130, 246, 0.6); }
}

@keyframes data-stream {
  0% { transform: translateY(-100%); opacity: 0; }
  50% { opacity: 1; }
  100% { transform: translateY(100vh); opacity: 0; }
}

@keyframes matrix-rain {
  0% { transform: translateY(-100%); }
  100% { transform: translateY(100vh); }
}

@keyframes gradient-shift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

/* 科技感背景元素 */
.tech-bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  pointer-events: none;
  z-index: 0;
}

.tech-bg::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--color-primary), transparent);
  animation: tech-bg 3s linear infinite;
}


/* 浮动科技元素 */
.tech-float {
  animation: float 3s ease-in-out infinite;
}

.tech-float:nth-child(2) {
  animation-delay: 1s;
}

.tech-float:nth-child(3) {
  animation-delay: 2s;
}

/* 发光按钮效果 */
.btn-tech {
  position: relative;
  overflow: hidden;
  animation: pulse-glow 2s ease-in-out infinite;
}

.btn-tech::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  animation: tech-bg 2s linear infinite;
}

/* 数据流效果 */
.data-stream {
  position: absolute;
  width: 2px;
  height: 20px;
  background: var(--color-primary);
  opacity: 0.6;
  animation: data-stream 3s linear infinite;
}

.data-stream:nth-child(1) { left: 10%; animation-delay: 0s; }
.data-stream:nth-child(2) { left: 30%; animation-delay: 1s; }
.data-stream:nth-child(3) { left: 50%; animation-delay: 2s; }
.data-stream:nth-child(4) { left: 70%; animation-delay: 0.5s; }
.data-stream:nth-child(5) { left: 90%; animation-delay: 1.5s; }

/* 矩阵雨效果 */
.matrix-rain {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  pointer-events: none;
  z-index: 0;
}

.matrix-rain::before,
.matrix-rain::after {
  content: 'BOUNDLESS';
  position: absolute;
  top: -100px;
  left: 0;
  width: 100%;
  color: var(--color-primary);
  font-family: 'Courier New', monospace;
  font-size: 12px;
  opacity: 0.3;
  animation: matrix-rain 8s linear infinite;
}

.matrix-rain::after {
  content: '无界青年论坛';
  left: 20%;
  animation-delay: 4s;
}

/* 科技感卡片悬停效果 */
.card-tech {
  position: relative;
  overflow: hidden;
  transition: all 0.3s ease;
}

.card-tech::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(59, 130, 246, 0.1), transparent);
  transition: left 0.5s ease;
}

.card-tech:hover::before {
  left: 100%;
}

.card-tech:hover {
  transform: translateY(-5px);
  box-shadow: 0 10px 30px rgba(59, 130, 246, 0.2);
}

/* 科技感文字效果 */
.text-tech {
  position: relative;
  background: linear-gradient(45deg, var(--color-text), var(--color-primary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  animation: float 2s ease-in-out infinite;
}

/* 扫描线效果 */
.scan-line {
  position: relative;
  overflow: hidden;
}

.scan-line::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--color-primary), transparent);
  animation: tech-bg 2s linear infinite;
}

/* ==================== Scroll Reveal Animations ==================== */

/* Initial hidden state for elements to be revealed */
.reveal {
  opacity: 0;
  filter: blur(10px);
  transform: translateY(var(--reveal-distance));
  transition: 
    opacity var(--reveal-duration) ease-out,
    filter var(--reveal-duration) ease-out,
    transform var(--reveal-duration) ease-out;
}

/* Revealed state */
.reveal.revealed {
  opacity: 1;
  filter: blur(0);
  transform: translateY(0);
}

/* Staggered animations for grid children */
.reveal-stagger > * {
  opacity: 0;
  filter: blur(8px);
  transform: translateY(30px);
  transition: 
    opacity var(--reveal-duration) ease-out,
    filter var(--reveal-duration) ease-out,
    transform var(--reveal-duration) ease-out;
}

.reveal-stagger.revealed > *:nth-child(1) {
  opacity: 1;
  filter: blur(0);
  transform: translateY(0);
  transition-delay: calc(var(--reveal-stagger) * 0);
}

.reveal-stagger.revealed > *:nth-child(2) {
  opacity: 1;
  filter: blur(0);
  transform: translateY(0);
  transition-delay: calc(var(--reveal-stagger) * 1);
}

.reveal-stagger.revealed > *:nth-child(3) {
  opacity: 1;
  filter: blur(0);
  transform: translateY(0);
  transition-delay: calc(var(--reveal-stagger) * 2);
}

.reveal-stagger.revealed > *:nth-child(4) {
  opacity: 1;
  filter: blur(0);
  transform: translateY(0);
  transition-delay: calc(var(--reveal-stagger) * 3);
}

.reveal-stagger.revealed > *:nth-child(5) {
  opacity: 1;
  filter: blur(0);
  transform: translateY(0);
  transition-delay: calc(var(--reveal-stagger) * 4);
}

.reveal-stagger.revealed > *:nth-child(6) {
  opacity: 1;
  filter: blur(0);
  transform: translateY(0);
  transition-delay: calc(var(--reveal-stagger) * 5);
}

.reveal-stagger.revealed > *:nth-child(n+7) {
  opacity: 1;
  filter: blur(0);
  transform: translateY(0);
  transition-delay: calc(var(--reveal-stagger) * 6);
}

/* Fade from left */
.reveal-left {
  opacity: 0;
  filter: blur(10px);
  transform: translateX(-40px);
  transition: 
    opacity var(--reveal-duration) ease-out,
    filter var(--reveal-duration) ease-out,
    transform var(--reveal-duration) ease-out;
}

.reveal-left.revealed {
  opacity: 1;
  filter: blur(0);
  transform: translateX(0);
}

/* Fade from right */
.reveal-right {
  opacity: 0;
  filter: blur(10px);
  transform: translateX(40px);
  transition: 
    opacity var(--reveal-duration) ease-out,
    filter var(--reveal-duration) ease-out,
    transform var(--reveal-duration) ease-out;
}

.reveal-right.revealed {
  opacity: 1;
  filter: blur(0);
  transform: translateX(0);
}

/* Scale reveal */
.reveal-scale {
  opacity: 0;
  filter: blur(8px);
  transform: scale(0.9);
  transition: 
    opacity 0.6s ease-out,
    filter 0.6s ease-out,
    transform 0.6s ease-out;
}

.reveal-scale.revealed {
  opacity: 1;
  filter: blur(0);
  transform: scale(1);
}

/* Reduce motion for accessibility */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  
  .reveal,
  .reveal-stagger > *,
  .reveal-left,
  .reveal-right,
  .reveal-scale {
    opacity: 1;
    filter: none;
    transform: none;
  }
}

/* ==================== Responsive ==================== */
@media (max-width: 767px) {
  .header nav {
    display: none; /* 默认隐藏 */
    position: fixed;
    top: 64px;
    right: -100%;
    width: 100vw;
    max-width: 320px;
    height: calc(100vh - 64px);
    background: var(--color-bg);
    border-left: 1px solid var(--color-border);
    transition: right 0.3s ease;
    overflow-y: auto;
    z-index: 1000;
  }
  
  /* 当data-open="true"时显示导航 */
  .header nav[data-open="true"] {
    display: block !important;
    right: 0;
  }
  
  .header nav[data-open="false"] {
    right: -100%;
  }
  
  .header nav ul {
    flex-direction: column;
    padding: var(--space-4);
    gap: 0;
    width: 100%;
    box-sizing: border-box;
  }
  
  .header nav ul li {
    width: 100%;
    border-bottom: 1px solid var(--color-border);
    box-sizing: border-box;
  }
  
  .header nav ul li:last-child {
    border-bottom: none;
  }
  
  .header nav ul li a,
  .header nav ul li button {
    width: 100%;
    padding: var(--space-3);
    text-align: left;
    box-sizing: border-box;
    display: block;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }
  
  /* 语言切换按钮特殊样式 */
  .header nav ul li:last-child {
    border-bottom: none;
    margin-top: var(--space-2);
    padding-top: var(--space-2);
  }
  
  .header nav ul li:last-child button {
    text-align: center;
    font-weight: 600;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 8px;
    margin: 0 var(--space-2);
  }
  
  /* Mobile hero adjustments */
  .hero {
    padding: 48px 0 32px;
  }
  
  .hero .grid.cols-2 {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }
  
  .hero .grid > div {
    width: 100%;
  }
}

@media (min-width: 768px) {
  .nav-links { 
    display: inline-flex; 
  }
  .nav-toggle { 
    display: none; 
  }
  .header nav {
    position: relative;
    display: flex !important;
  }
  
  .header nav[data-open] {
    position: relative;
    right: auto;
    width: auto;
    height: auto;
    background: transparent;
    border: none;
  }
  .hero { 
    padding: 80px 0 60px; 
  }
  .section {
    padding: 64px 0;
  }
  .footer-content {
    text-align: left;
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (min-width: 1024px) {
  .container {
    padding-inline: var(--space-6);
  }
  .hero {
    padding: 100px 0 80px;
  }
  .hero .grid > div:first-child {
    max-width: 900px;
  }
  
  .brand-title {
    font-size: 4rem;
  }
  .hero .grid > div:last-child {
    width: 100vw;
    margin-left: calc(-50vw + 50%);
    margin-right: calc(-50vw + 50%);
    max-width: none;
  }
  .section {
    padding: 80px 0;
  }
}

/* ==================== Carousel ==================== */
.carousel {
  position: relative;
  width: 100%;
  max-width: 100%;
  overflow: hidden;
  border-radius: var(--radius-md);
  background: transparent;
  box-shadow: none;
}

.carousel-track {
  display: flex;
  transition: transform 0.5s ease-in-out;
}

.carousel-slide {
  min-width: 100%;
  position: relative;
  display: block;
  text-decoration: none;
  overflow: hidden;
}

.carousel-slide img {
  width: 100%;
  height: auto;
  aspect-ratio: 21 / 9;
    object-fit: cover;
    display: block;
  transition: transform 0.3s ease;
}

/* 移动端轮播图更高 */
@media (max-width: 767px) {
  .carousel-slide img {
    aspect-ratio: 16 / 9; /* 移动端使用更高的比例 */
  }
}

.carousel-slide:hover img {
  transform: scale(1.05);
}

.carousel-overlay {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: var(--space-4);
  background: linear-gradient(to top, rgba(0, 0, 0, 0.8), transparent);
  color: white;
  transform: translateY(0);
  transition: transform 0.3s ease;
}

.carousel-overlay h3 {
  margin: 0 0 var(--space-2);
  font-size: 18px;
  font-weight: 600;
}

.carousel-overlay p {
  margin: 0;
  font-size: 14px;
  opacity: 0.9;
  line-height: 1.5;
}

.carousel-btn {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  background: rgba(255, 255, 255, 0.9);
  color: var(--color-text);
  border: none;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  font-size: 24px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
  z-index: 10;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.carousel-btn:hover {
  background: white;
  transform: translateY(-50%) scale(1.1);
}

.carousel-btn.prev {
  left: 12px;
}

.carousel-btn.next {
  right: 12px;
}

.carousel-cta {
  display: block;
  text-align: center;
  padding: var(--space-3);
  color: var(--color-primary);
  text-decoration: none;
  font-weight: 600;
  font-size: 15px;
  transition: color 0.2s ease;
  background: var(--color-bg);
  border-top: 1px solid var(--color-border);
}

.carousel-cta:hover {
  color: var(--color-text);
}

/* ==================== Utility Classes ==================== */
.text-center { text-align: center; }
.text-muted { color: var(--color-muted); }
.mt-4 { margin-top: var(--space-4); }
.mt-8 { margin-top: var(--space-8); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-8 { margin-bottom: var(--space-8); }