/* AI EXPO 2026 创新创业大赛 - 全局样式表 */

/* =====================
   1. CSS 变量定义
   ===================== */
:root {
  /* 主背景色 */
  --bg-primary: #0a1628;
  --bg-secondary: #1a2a4a;
  --bg-card: #0f2040;
  --bg-card-alt: #162850;
  --bg-footer: #060e1c;
  
  /* 强调色 - 玫红 */
  --color-pink: #e91e8c;
  --color-pink-light: #ff2d8a;
  
  /* 强调色 - 亮青 */
  --color-cyan: #00d4ff;
  --color-cyan-light: #4cf0ff;
  
  /* 文字颜色 */
  --text-primary: #ffffff;
  --text-secondary: #a0b4cc;
  --text-muted: #c0d0e0;
  
  /* 渐变 */
  --gradient-pink: linear-gradient(135deg, #e91e8c, #ff2d8a);
  --gradient-cyan: linear-gradient(135deg, #00d4ff, #4cf0ff);
  
  /* 间距 */
  --nav-height: 70px;
  --container-width: 1200px;
}

/* =====================
   2. 全局重置
   ===================== */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Source Han Sans CN", -apple-system, sans-serif;
  background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
  color: var(--text-primary);
  line-height: 1.8;
  overflow-x: hidden;
  min-height: 100vh;
  position: relative;
}

a {
  color: inherit;
  text-decoration: none;
}

ul, ol {
  list-style: none;
}

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

/* =====================
   3. 背景纹理
   ===================== */
body::before {
  content: '';
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image: url('../images/circuit_texture.png');
  background-size: 400px 400px;
  opacity: 0.07;
  pointer-events: none;
  z-index: 0;
}

/* =====================
   4. 容器
   ===================== */
.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 40px;
  position: relative;
  z-index: 1;
}

/* =====================
   5. 导航栏
   ===================== */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(10, 22, 40, 0.88);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  z-index: 1000;
  border-bottom: 1px solid rgba(0, 212, 255, 0.1);
  transition: background 0.3s ease;
}

.navbar.scrolled {
  background: rgba(10, 22, 40, 0.98);
}

.navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 100%;
}

.navbar-brand {
  font-size: 17px;
  font-weight: 700;
  color: var(--text-primary);
  letter-spacing: 0.5px;
}

.navbar-brand span {
  color: var(--color-cyan);
}

.navbar-menu {
  display: flex;
  gap: 8px;
}

.navbar-menu a {
  padding: 8px 14px;
  font-size: 14px;
  color: var(--text-secondary);
  transition: all 0.3s ease;
  position: relative;
  border-radius: 4px;
}

.navbar-menu a::after {
  content: '';
  position: absolute;
  bottom: 2px;
  left: 14px;
  right: 14px;
  height: 2px;
  background: var(--color-cyan);
  transform: scaleX(0);
  transition: transform 0.3s ease;
}

.navbar-menu a:hover {
  color: var(--text-primary);
}

.navbar-menu a:hover::after {
  transform: scaleX(1);
}

.navbar-menu a.active {
  color: var(--text-primary);
}

.navbar-menu a.active::after {
  transform: scaleX(1);
}

/* 汉堡菜单按钮 */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 10px;
  z-index: 1001;
}

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  transition: all 0.3s ease;
}

.hamburger.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.hamburger.active span:nth-child(2) {
  opacity: 0;
}

.hamburger.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* 移动端菜单 */
@media (max-width: 900px) {
  .hamburger {
    display: flex;
  }
  
  .navbar-menu {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: rgba(6, 14, 28, 0.98);
    flex-direction: column;
    padding: 20px;
    gap: 10px;
    transform: translateY(-100%);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
  }
  
  .navbar-menu.active {
    transform: translateY(0);
    opacity: 1;
    visibility: visible;
  }
  
  .navbar-menu a {
    padding: 12px 16px;
    font-size: 15px;
    border-bottom: 1px solid rgba(0, 212, 255, 0.1);
  }
  
  .navbar-menu a::after {
    display: none;
  }
}

/* =====================
   6. 直角装饰框
   ===================== */
.corner-decor {
  position: relative;
}

.corner-decor::before,
.corner-decor::after {
  content: '';
  position: absolute;
  width: 70px;
  height: 70px;
  border-color: var(--color-cyan-light);
  border-style: solid;
  opacity: 0.4;
  pointer-events: none;
}

.corner-decor::before {
  top: 0;
  left: 0;
  border-width: 2px 0 0 2px;
  border-radius: 4px 0 0 0;
}

.corner-decor::after {
  bottom: 0;
  right: 0;
  border-width: 0 2px 2px 0;
  border-radius: 0 0 4px 0;
}

/* =====================
   7. 区块标题
   ===================== */
.section-header {
  text-align: center;
  padding: 80px 0 50px;
}

.section-title-text h2 {
  font-size: 36px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.section-title-text .en {
  font-size: 18px;
  color: var(--text-secondary);
  font-weight: 400;
}

.title-line {
  width: 100%;
  max-width: 400px;
  height: 2px;
  background: linear-gradient(to right, transparent, var(--color-cyan), transparent);
  margin: 12px auto 0;
  border-radius: 1px;
}

/* =====================
   8. 卡片
   ===================== */
.card {
  background: var(--bg-card);
  border-radius: 12px;
  padding: 32px;
  box-shadow: inset 0 1px 3px rgba(0, 0, 0, 0.3);
  position: relative;
  overflow: hidden;
}

.card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(to right, transparent, rgba(0, 212, 255, 0.3), transparent);
}

/* =====================
   9. 按钮
   ===================== */
.btn-primary {
  display: inline-block;
  padding: 14px 40px;
  background: var(--gradient-pink);
  color: #fff;
  font-size: 16px;
  font-weight: 700;
  border-radius: 8px;
  border: none;
  cursor: pointer;
  transition: all 0.3s ease;
  text-align: center;
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 25px rgba(233, 30, 140, 0.5);
}

.btn-secondary {
  display: inline-block;
  padding: 12px 32px;
  background: transparent;
  color: var(--text-primary);
  font-size: 15px;
  font-weight: 500;
  border-radius: 8px;
  border: 1px solid var(--color-cyan);
  cursor: pointer;
  transition: all 0.3s ease;
}

.btn-secondary:hover {
  background: rgba(0, 212, 255, 0.1);
  border-color: var(--color-cyan-light);
}

/* =====================
   10. 浮动报名按钮
   ===================== */
.floating-btn {
  position: fixed;
  right: 30px;
  bottom: 40px;
  z-index: 999;
  animation: floatPulse 2s ease-in-out infinite;
}

.floating-btn .btn-primary {
  padding: 16px 36px;
  font-size: 16px;
  box-shadow: 0 6px 20px rgba(233, 30, 140, 0.4);
}

@keyframes floatPulse {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-6px);
  }
}

/* =====================
   11. 页脚
   ===================== */
.footer {
  background: var(--bg-footer);
  padding: 50px 0 30px;
  margin-top: 0px;
  border-top: 1px solid rgba(0, 212, 255, 0.15);
  position: relative;
  z-index: 1;
}

.footer-content {
  display: flex;
  justify-content: center;
  align-items: flex-start;
  gap: 0;
  color: var(--text-secondary);
  font-size: 13px;
  line-height: 2;
}

.footer-col-left {
  text-align: left;
  padding-right: 60px;
  min-width: 320px;
}

.footer-col-right {
  text-align: left;
  padding-left: 60px;
  min-width: 320px;
}

.footer-divider-vertical {
  width: 1px;
  background: rgba(255, 255, 255, 0.3);
  align-self: stretch;
}

.footer-content p {
  margin-bottom: 8px;
}

.footer-content a {
  color: var(--color-cyan-light);
  transition: color 0.3s ease;
}

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

.footer-divider {
  width: 100%;
  max-width: 600px;
  height: 1px;
  background: linear-gradient(to right, transparent, var(--color-cyan), transparent);
  margin: 30px auto;
}

.footer-copyright {
  text-align: center;
  font-size: 12px;
  color: var(--text-muted);
  opacity: 0.7;
}

/* =====================
   12. Hero Banner 样式
   ===================== */
.hero-banner {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 120px 20px 80px;
  position: relative;
  overflow: hidden;
}

.hero-banner::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(ellipse at 50% 0%, rgba(0, 212, 255, 0.15) 0%, transparent 60%);
  pointer-events: none;
}

.hero-banner::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 200px;
  background: linear-gradient(to top, rgba(0, 212, 255, 0.08), transparent);
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 2;
  max-width: 900px;
}

.hero-title {
  font-size: 52px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 16px;
  letter-spacing: 2px;
  text-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.hero-subtitle {
  font-size: 22px;
  color: var(--color-cyan-light);
  margin-bottom: 16px;
  font-weight: 400;
  letter-spacing: 1px;
}

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

.hero-btn {
  margin-top: 20px;
}

/* 建筑轮廓装饰 */
.city-skyline {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 180px;
  z-index: 1;
  opacity: 0.15;
}

/* =====================
   13. 数字卡片
   ===================== */
.stats-section {
  padding: 60px 0;
}

.stats-grid {
  display: flex;
  justify-content: center;
  gap: 60px;
  flex-wrap: wrap;
}

.stat-card {
  background: var(--bg-card);
  border-radius: 16px;
  padding: 40px 50px;
  text-align: center;
  min-width: 180px;
  box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.3);
  position: relative;
  overflow: hidden;
}

.stat-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-pink);
}

.stat-number {
  font-size: 64px;
  font-weight: 700;
  color: var(--color-pink);
  line-height: 1.2;
}

.stat-label {
  font-size: 16px;
  color: var(--text-secondary);
  margin-top: 8px;
}

/* =====================
   14. 赛道卡片
   ===================== */
.tracks-section {
  padding: 40px 0 100px;
}

.tracks-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 30px;
}

.track-card {
  border-radius: 16px;
  padding: 40px;
  position: relative;
  overflow: hidden;
  min-height: 280px;
}

.track-card.regular {
  background: linear-gradient(135deg, #0c2a3a 0%, #0f3050 100%);
}

.track-card.opc {
  background: linear-gradient(135deg, #2a0c3a 0%, #3a1060 100%);
}

.track-card .badge {
  position: absolute;
  top: 20px;
  right: 20px;
  background: var(--gradient-pink);
  color: #fff;
  font-size: 12px;
  font-weight: 600;
  padding: 6px 14px;
  border-radius: 20px;
}

.track-card .icon {
  width: 60px;
  height: 60px;
  margin-bottom: 20px;
  opacity: 0.8;
}

.track-card h3 {
  font-size: 26px;
  font-weight: 700;
  margin-bottom: 6px;
}

.track-card h3 small {
  display: block;
  font-size: 14px;
  font-weight: 400;
  color: var(--text-secondary);
  margin-top: 4px;
}

.track-card p {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.8;
  margin-top: 16px;
}

/* =====================
   15. 介绍卡片
   ===================== */
.intro-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
  margin: 50px 0;
}

.intro-card {
  background: var(--bg-card);
  border-radius: 12px;
  padding: 36px;
  position: relative;
  overflow: hidden;
  min-height: 320px;
}

.intro-card .card-number {
  font-size: 48px;
  font-weight: 700;
  color: var(--color-pink);
  opacity: 0.6;
  position: absolute;
  top: 15px;
  right: 20px;
}

.intro-card .card-icon {
  width: 50px;
  height: 50px;
  margin-bottom: 20px;
  opacity: 0.8;
}

.intro-card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 16px;
  position: relative;
}

.intro-card h3::after {
  content: '';
  display: block;
  width: 40px;
  height: 2px;
  background: var(--gradient-cyan);
  margin-top: 10px;
}

.intro-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.9;
}

/* =====================
   16. 标签云
   ===================== */
.tag-cloud {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

.tag {
  display: inline-block;
  padding: 8px 18px;
  background: rgba(0, 212, 255, 0.1);
  border: 1px solid rgba(0, 212, 255, 0.3);
  border-radius: 25px;
  font-size: 13px;
  color: var(--color-cyan-light);
  transition: all 0.3s ease;
}

.tag:hover {
  background: rgba(0, 212, 255, 0.2);
  border-color: var(--color-cyan);
  transform: translateY(-2px);
}

/* =====================
   17. 奖项卡片
   ===================== */
.awards-section {
  padding: 40px 0;
}

.award-card {
  border-radius: 12px;
  padding: 28px 32px;
  margin-bottom: 20px;
  position: relative;
  overflow: hidden;
}

.award-card.first {
  background: var(--gradient-pink);
}

.award-card.second {
  background: linear-gradient(135deg, #0c3a4a 0%, #0c5060 100%);
}

.award-card.third {
  background: linear-gradient(135deg, #0c4a5a 0%, #0c6070 100%);
}

.award-card.potential {
  background: linear-gradient(135deg, #d4508a 0%, #e060a0 100%);
}

.award-card.special {
  background: linear-gradient(135deg, #3a1a5a 0%, #4a2a7a 100%);
}

.award-card.opc-first {
  background: linear-gradient(135deg, #8a1a5a 0%, #a0206a 100%);
}

.award-card.opc-second {
  background: linear-gradient(135deg, #1a2a5a 0%, #2a3a7a 100%);
}

.award-card.opc-third {
  background: linear-gradient(135deg, #0a1a4a 0%, #1a2a6a 100%);
}

.award-card.opc-potential {
  background: linear-gradient(135deg, #2a3a4a 0%, #3a4a6a 100%);
}

.award-header {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 16px;
}

.award-tag {
  display: inline-block;
  padding: 8px 20px;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 6px;
  font-weight: 700;
  font-size: 16px;
}

.award-tag .count {
  font-weight: 400;
  opacity: 0.8;
  margin-left: 8px;
}

.award-body h4 {
  font-size: 36px;
  font-weight: 700;
  margin-bottom: 8px;
}

.award-body p {
  font-size: 14px;
  opacity: 0.9;
  line-height: 1.7;
}

.award-body .small {
  font-size: 14px;
  margin-top: 4px;
}

.awards-row {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.award-row-item {
  margin-bottom: 0;
}

.notes-section {
  background: rgba(0, 0, 0, 0.2);
  border-radius: 12px;
  padding: 30px;
  margin-top: 40px;
}

.notes-section h4 {
  font-size: 18px;
  color: var(--color-cyan-light);
  margin-bottom: 16px;
}

.notes-section ol {
  padding-left: 20px;
}

.notes-section li {
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 12px;
  line-height: 1.7;
  list-style: decimal;
}

/* =====================
   18. 时间轴
   ===================== */
.timeline-section {
  padding: 40px 0;
}

.timeline {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  position: relative;
  padding: 40px 0;
  margin-bottom: 60px;
}

.timeline::before {
  content: '';
  position: absolute;
  top: 70px;
  left: 10%;
  right: 10%;
  height: 2px;
  background: linear-gradient(to right, transparent, var(--color-cyan), var(--color-cyan), transparent);
}

.timeline-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  flex: 1;
  position: relative;
  z-index: 2;
}

.timeline-icon {
  width: 80px;
  height: 80px;
  background: var(--bg-card);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
  border: 2px solid var(--color-cyan);
  box-shadow: 0 0 20px rgba(0, 212, 255, 0.3);
}

.timeline-icon svg {
  width: 40px;
  height: 40px;
  fill: var(--color-cyan);
}

.timeline-date {
  font-size: 14px;
  color: var(--color-pink);
  font-weight: 600;
  margin-bottom: 8px;
}

.timeline-label {
  font-size: 15px;
  color: var(--text-primary);
  font-weight: 600;
}

/* 时间轴图片卡片 */
.timeline-images {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  margin-bottom: 20px;
}

.timeline-img-card {
  background: var(--bg-card);
  border-radius: 12px;
  overflow: hidden;
  position: relative;
}

.timeline-img-card img {
  width: 100%;
  height: 160px;
  object-fit: cover;
  opacity: 0.8;
}

.timeline-img-card .img-label {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 15px;
  background: linear-gradient(to top, rgba(0,0,0,0.8), transparent);
  font-size: 13px;
  color: var(--text-primary);
}

.timeline-img-card .img-label span {
  color: var(--color-pink);
}

.timeline-note {
  text-align: center;
  font-size: 13px;
  color: var(--text-muted);
  margin-bottom: 60px;
}

/* 阶段详情 */
.schedule-phases {
  margin-top: 40px;
}

.phase-card {
  background: var(--bg-card);
  border-radius: 12px;
  padding: 30px 36px;
  margin-bottom: 20px;
  position: relative;
  overflow: hidden;
}

.phase-card::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 4px;
  background: var(--gradient-pink);
}

.phase-header {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-bottom: 16px;
}

.phase-number {
  width: 40px;
  height: 40px;
  background: var(--gradient-pink);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 18px;
}

.phase-title {
  font-size: 20px;
  font-weight: 700;
}

.phase-time {
  font-size: 14px;
  color: var(--color-pink);
  margin-left: auto;
}

.phase-content {
  padding-left: 56px;
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.9;
}

.phase-content ul {
  margin-top: 12px;
  padding-left: 20px;
}

.phase-content li {
  list-style: disc;
  margin-bottom: 6px;
}

/* =====================
   19. 新闻列表
   ===================== */
.news-section {
  padding: 40px 0 100px;
}

.news-list {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.news-item {
  display: flex;
  gap: 30px;
  padding: 30px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  transition: background 0.3s ease;
}

.news-item:hover {
  background: rgba(0, 212, 255, 0.03);
}

.news-date {
  flex-shrink: 0;
  width: 80px;
  text-align: center;
}

.news-date .month {
  font-size: 32px;
  font-weight: 700;
  color: var(--color-pink);
  line-height: 1.2;
}

.news-date .day {
  font-size: 20px;
  color: var(--text-primary);
}

.news-content h3 {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 10px;
  line-height: 1.5;
}

.news-content h3 a {
  transition: color 0.3s ease;
}

.news-content h3 a:hover {
  color: var(--color-cyan-light);
}

.news-content p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.news-more {
  text-align: center;
  margin-top: 50px;
}

/* =====================
   20. 征集范围
   ===================== */
.eligibility-section {
  padding: 40px 0 100px;
}

.eligibility-block {
  margin-bottom: 60px;
}

.eligibility-block .block-title {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 20px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.eligibility-block .block-title::before {
  content: '';
  width: 4px;
  height: 28px;
  background: var(--gradient-cyan);
  border-radius: 2px;
}

.eligibility-text {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 2;
  margin-bottom: 24px;
}

.opc-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-top: 30px;
}

.opc-card {
  background: var(--bg-card);
  border-radius: 12px;
  padding: 28px;
  position: relative;
  overflow: hidden;
}

.opc-card.type1 {
  background: linear-gradient(135deg, #1a0a3a 0%, #2a1a5a 100%);
}

.opc-card.type2 {
  background: linear-gradient(135deg, #0a2a3a 0%, #1a3a5a 100%);
}

.opc-card.type3 {
  background: linear-gradient(135deg, #0a1a3a 0%, #1a2a5a 100%);
}

.opc-card h4 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 16px;
  color: var(--color-cyan-light);
}

.opc-card ul {
  font-size: 13px;
  color: var(--text-secondary);
  line-height: 1.9;
}

.opc-card li {
  list-style: none;
  padding-left: 16px;
  position: relative;
}

.opc-card li::before {
  content: '•';
  position: absolute;
  left: 0;
  color: var(--color-pink);
}

/* =====================
   21. 项目要求
   ===================== */
.requirements-section {
  padding: 40px 0 100px;
}

.requirements-list {
  margin-bottom: 50px;
}

.requirements-list h3 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.requirements-list h3::before {
  content: '';
  width: 4px;
  height: 28px;
  background: var(--gradient-cyan);
  border-radius: 2px;
}

.requirements-list ol {
  padding-left: 0;
  counter-reset: req-counter;
}

.requirements-list li {
  list-style: none;
  counter-increment: req-counter;
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.9;
  padding: 16px 20px 16px 60px;
  margin-bottom: 12px;
  background: var(--bg-card);
  border-radius: 8px;
  position: relative;
}

.requirements-list li::before {
  content: counter(req-counter);
  position: absolute;
  left: 20px;
  top: 50%;
  transform: translateY(-50%);
  width: 28px;
  height: 28px;
  background: var(--gradient-pink);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 14px;
  color: #fff;
}

.stage-box {
  background: rgba(0, 212, 255, 0.08);
  border: 1px solid rgba(0, 212, 255, 0.3);
  border-radius: 12px;
  padding: 24px 30px;
  margin-bottom: 50px;
}

.stage-box h4 {
  font-size: 16px;
  color: var(--color-cyan-light);
  margin-bottom: 8px;
}

.stage-box p {
  font-size: 15px;
  color: var(--text-primary);
}

/* =====================
   22. 参赛须知
   ===================== */
.info-section {
  padding: 40px 0 100px;
}

.info-block {
  margin-bottom: 50px;
}

.info-block h3 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.info-block h3::before {
  content: '';
  width: 4px;
  height: 28px;
  background: var(--gradient-cyan);
  border-radius: 2px;
}

.info-block ol {
  padding-left: 0;
  counter-reset: info-counter;
}

.info-block li {
  list-style: none;
  counter-increment: info-counter;
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.9;
  padding: 16px 20px 16px 60px;
  margin-bottom: 12px;
  background: var(--bg-card);
  border-radius: 8px;
  position: relative;
}

.info-block li::before {
  content: counter(info-counter);
  position: absolute;
  left: 20px;
  top: 50%;
  transform: translateY(-50%);
  width: 28px;
  height: 28px;
  background: var(--gradient-pink);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 14px;
  color: #fff;
}

/* =====================
   23. 联系我们
   ===================== */
.contact-section {
  padding: 40px 0 100px;
}

.contact-intro {
  font-size: 16px;
  color: var(--text-secondary);
  text-align: center;
  margin-bottom: 50px;
}

.contact-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
  margin-bottom: 60px;
}

.contact-card {
  background: var(--bg-card);
  border-radius: 12px;
  padding: 32px;
  text-align: center;
}

.contact-card .icon {
  width: 50px;
  height: 50px;
  margin: 0 auto 16px;
  opacity: 0.8;
}

.contact-card h4 {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 8px;
  font-weight: 400;
}

.contact-card p {
  font-size: 16px;
  color: var(--text-primary);
  font-weight: 500;
}

.contact-card a {
  color: var(--color-cyan-light);
  transition: color 0.3s ease;
}

.contact-card a:hover {
  color: var(--text-primary);
}

.org-structure {
  margin-bottom: 60px;
}

.org-structure h3 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 30px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.org-structure h3::before {
  content: '';
  width: 4px;
  height: 28px;
  background: var(--gradient-cyan);
  border-radius: 2px;
}

.org-level {
  margin-bottom: 24px;
}

.org-level h4 {
  font-size: 15px;
  color: var(--color-pink);
  font-weight: 600;
  margin-bottom: 12px;
  padding-left: 16px;
  position: relative;
}

.org-level h4::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 6px;
  height: 6px;
  background: var(--color-pink);
  border-radius: 50%;
}

.org-level ul {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  padding-left: 16px;
}

.org-level li {
  font-size: 14px;
  color: var(--text-secondary);
  background: var(--bg-card);
  padding: 8px 16px;
  border-radius: 6px;
}

.alliance-intro {
  margin-bottom: 60px;
}

.alliance-intro h3 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 24px;
  display: flex;
  align-items: center;
  gap: 12px;
}

.alliance-intro h3::before {
  content: '';
  width: 4px;
  height: 28px;
  background: var(--gradient-cyan);
  border-radius: 2px;
}

.alliance-intro h4 {
  font-size: 16px;
  color: var(--color-cyan-light);
  margin-bottom: 12px;
  margin-top: 24px;
}

.alliance-intro p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 2;
}

.leadership-card {
  background: var(--bg-card);
  border-radius: 12px;
  padding: 30px;
  margin-top: 24px;
}

.leadership-card h4 {
  font-size: 16px;
  color: var(--color-cyan-light);
  margin-bottom: 16px;
}

.leadership-list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 16px;
}

.leadership-item {
  font-size: 14px;
  color: var(--text-secondary);
  padding: 12px 16px;
  background: rgba(0, 0, 0, 0.2);
  border-radius: 8px;
}

.leadership-item strong {
  color: var(--text-primary);
}

.city-panorama {
  width: 100%;
  height: 300px;
  background: var(--bg-card);
  border-radius: 12px;
  margin-top: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 14px;
  overflow: hidden;
}

.city-panorama img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

/* =====================
   24. 图片占位
   ===================== */
.placeholder-img {
  background: linear-gradient(135deg, var(--bg-card) 0%, #1a2a4a 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-muted);
  font-size: 13px;
  text-align: center;
  padding: 20px;
}

/* Logo墙 */
.logo-wall {
  background: #fff;
  border-radius: 12px;
  padding: 40px;
  margin: 30px 0;
}

.logo-wall h3 {
  color: #333;
  font-size: 18px;
  text-align: center;
  margin-bottom: 8px;
}

.logo-wall .sub {
  color: #666;
  font-size: 13px;
  text-align: center;
  margin-bottom: 24px;
}

/* =====================
   25. 页面入场动画
   ===================== */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* =====================
   26. 响应式设计
   ===================== */
@media (max-width: 1024px) {
  .container {
    padding: 0 30px;
  }
  
  .hero-title {
    font-size: 42px;
  }
  
  .intro-cards {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .opc-cards {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .container {
    padding: 0 20px;
  }
  
  .section-header {
    padding: 60px 0 30px;
    flex-wrap: wrap;
  }
  
  .section-title-text h2 {
    font-size: 26px;
  }
  
  .section-title-text .en {
    font-size: 14px;
  }
  
  .hero-title {
    font-size: 28px;
    letter-spacing: 1px;
  }
  
  .hero-subtitle {
    font-size: 16px;
  }
  
  .stats-grid {
    gap: 20px;
  }
  
  .stat-card {
    padding: 30px 40px;
    min-width: 140px;
  }
  
  .stat-number {
    font-size: 48px;
  }
  
  .tracks-grid {
    grid-template-columns: 1fr;
  }
  
  .intro-cards {
    grid-template-columns: 1fr;
  }
  
  .awards-row {
    grid-template-columns: 1fr;
  }
  
  .timeline {
    flex-direction: column;
    gap: 30px;
    align-items: center;
  }
  
  .timeline::before {
    display: none;
  }
  
  .timeline-images {
    grid-template-columns: repeat(2, 1fr);
  }
  
  .contact-cards {
    grid-template-columns: 1fr;
  }
  
  .opc-cards {
    grid-template-columns: 1fr;
  }
  
  .phase-content {
    padding-left: 0;
    margin-top: 12px;
  }
  
  .phase-header {
    flex-wrap: wrap;
  }
  
  .phase-time {
    margin-left: 0;
    width: 100%;
    margin-top: 8px;
  }
  
  .award-body h4 {
    font-size: 28px;
  }
  
  .leadership-list {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 480px) {
  .hero-title {
    font-size: 24px;
  }
  
  .stat-card {
    padding: 24px 30px;
    width: 100%;
  }
  
  .timeline-images {
    grid-template-columns: 1fr;
  }
  
  .award-header {
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }
}

/* =====================
   27. 辅助类
   ===================== */
.text-center {
  text-align: center;
}

.text-pink {
  color: var(--color-pink);
}

.text-cyan {
  color: var(--color-cyan-light);
}

.mt-20 {
  margin-top: 20px;
}

.mt-40 {
  margin-top: 40px;
}

.mb-20 {
  margin-bottom: 20px;
}

.mb-40 {
  margin-bottom: 40px;
}

/* 区块标题带边框 */
.block-title-border {
  background: var(--bg-card);
  border-radius: 12px;
  padding: 24px 30px;
  margin-bottom: 30px;
  border-left: 4px solid var(--color-pink);
}

/* 高亮标签 */
.highlight-tag {
  display: inline-block;
  padding: 6px 16px;
  background: var(--gradient-pink);
  border-radius: 20px;
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 16px;
}

.highlight-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

.highlight-tags .tag {
  background: rgba(233, 30, 140, 0.1);
  border-color: rgba(233, 30, 140, 0.3);
  color: var(--color-pink-light);
}

/* =====================
   底部声明横幅
   ===================== */
.bottom-banner {
  width: 100%;
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 360px;
  background: url('../images/bottom_banner.png') center bottom / cover no-repeat;
}
.bottom-banner::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: linear-gradient(to bottom, rgba(10,22,40,0.6), rgba(10,22,40,0.3));
}
.bottom-banner-text {
  position: relative;
  z-index: 2;
  text-align: center;
  padding: 60px 20px 20px;
  font-size: 20px;
  font-weight: 600;
  color: #ffffff;
  letter-spacing: 2px;
  line-height: 1.6;
  align-self: flex-start;
}
.indent-text {
  text-indent: 2em;
}