/* 全局基础 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  scroll-behavior: smooth;
}

html {
  scroll-padding-top: 80px;
}

body {
  background: #f8fafc;
  color: #1f2937;
  line-height: 1.85;
  padding-top: 70px;
  overflow-x: hidden;
}

/* 顶部悬浮导航 */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 70px;
  background: #ffffff;
  box-shadow: 0 2px 12px rgba(0,0,0,0.04);
  z-index: 999;
}
.nav-container {
  max-width: 1100px;
  height: 100%;
  margin: 0 auto;
  padding: 0 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.nav-logo {
  display: flex;
  align-items: center;
  gap: 12px;
  text-decoration: none;
}
.logo-icon {
  width: 34px;
  height: 34px;
  background: #1e293b;
  color: white;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
  font-size: 13px;
  letter-spacing: 0.5px;
}
.logo-text {
  font-size: 18px;
  font-weight: 600;
  color: #0f172a;
  letter-spacing: 0.4px;
}

/* 导航 */
.nav-menu {
  display: flex;
  gap: 22px;
  list-style: none;
  align-items: center;
}
.nav-menu a {
  text-decoration: none;
  color: #475569;
  font-size: 15px;
  transition: color 0.25s ease;
  position: relative;
}
.nav-menu a:hover {
  color: #2563eb;
}
.nav-menu a.active {
  color: #2563eb;
  font-weight: 500;
}
.nav-menu a.active::after {
  content: '';
  position: absolute;
  bottom: -6px;
  left: 0;
  width: 100%;
  height: 2px;
  background: #2563eb;
  border-radius: 1px;
}

/* 语言切换器 */
.lang-divider {
  color: #cbd5e1;
  margin: 0 4px;
  user-select: none;
}
.lang-item {
  list-style: none;
}
.lang-btn {
  border: none;
  background: transparent;
  color: #64748b;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  padding: 4px 8px;
  border-radius: 6px;
  transition: all 0.2s;
  font-family: inherit;
}
.lang-btn:hover {
  background: #f1f5f9;
  color: #2563eb;
}
.lang-btn.active {
  background: #2563eb;
  color: white;
}

/* PC端正常背景图 + 全称 + 标语 */
.hero {
  max-width: 100%;
  background: rgba(255,255,255,0.75) url("/static/images/bg-hero.jpg") center/cover no-repeat;
  background-blend-mode: overlay;
  padding: 80px 20px;
  text-align: center;
  margin-bottom: 40px;
  border-radius: 0 0 20px 20px;
}
.hero .slogan {
  font-size: 18px;
  color: #334155;
  max-width: 720px;
  margin: 0 auto;
  font-weight: 500;
  letter-spacing: 0.8px;
}

/* 内容容器 */
.container {
  max-width: 100%;
  width: 100%;
  padding: 0 16px 80px;
  margin: 0 auto;
  box-sizing: border-box;
  overflow-x: hidden;
}

/* 动画 */
.section {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  background: #ffffff;
  border-radius: 18px;
  padding: 32px 24px;
  margin-bottom: 24px;
  box-shadow: 0 4px 14px rgba(0,0,0,0.03);
  border: none;
  transition: all 0.32s ease;
  width: 100%;
  box-sizing: border-box;
  overflow: hidden;
  opacity: 0;
  transform: translateY(30px);
  animation: elegantFade 0.9s cubic-bezier(0.22, 1, 0.36, 1) forwards;
}
.section:nth-child(1) { animation-delay: 0.1s; }
.section:nth-child(2) { animation-delay: 0.2s; }
.section:nth-child(3) { animation-delay: 0.3s; }
.section:nth-child(4) { animation-delay: 0.4s; }
.section:nth-child(5) { animation-delay: 0.5s; }

@keyframes elegantFade {
  0% { opacity: 0; transform: translateY(30px); }
  100% { opacity: 1; transform: translateY(0); }
}

.section:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 20px rgba(0,0,0,0.06);
}

/* 统一图标 */
.section-title {
  width: 100%;
  font-size: 20px;
  font-weight: 600;
  color: #111827;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}
.section-title#home::before { content: "🏠"; }
.section-title#about::before { content: "🔖"; }
.section-title#mission::before { content: "🎯"; }
.section-title#advantage::before { content: "⭐"; }
.section-title#contact::before { content: "📩"; }

.section-content {
  width: 100%;
  font-size: 16px;
  color: #374151;
  line-height: 1.8;
  word-break: break-word;
  overflow-wrap: break-word;
}
.section-content p {
  margin-bottom: 14px;
}
.section-content li {
  list-style: none;
  margin-bottom: 12px;
}

/* 核心优势卡片 */
.advantage-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  width: 100%;
}
.advantage-item {
  background: #f9fafb;
  padding: 22px;
  border-radius: 14px;
  border: none;
  transition: 0.25s ease;
  width: 100%;
  box-sizing: border-box;
}
.advantage-item:hover {
  background: #eff6ff;
  transform: translateY(-2px);
}
.advantage-item h3 {
  font-size: 17px;
  font-weight: 600;
  color: #111827;
  margin-bottom: 8px;
}
.advantage-item p {
  font-size: 15px;
  color: #4b5563;
  line-height: 1.7;
}

/* 联系我们 */
.contact-content {
  display: flex;
  flex-direction: column;
  gap: 20px;
  width: 100%;
}
.contact-item {
  width: 100%;
}
.contact-item h3 {
  font-size: 17px;
  font-weight: 600;
  color: #111827;
  margin-bottom: 8px;
}
.contact-item p {
  font-size: 15px;
  color: #374151;
}

/* 底部 */
.footer {
  text-align: center;
  padding: 60px 20px;
  font-size: 14px;
  color: #94a3b8;
  background: #fff;
}

/* ============================== */
/* 手机端完美样式 */
/* ============================== */
@media (max-width: 768px) {
  .logo-text {
    display: none !important;
  }

  .nav-menu {
    gap: 12px;
    flex-wrap: wrap;
    justify-content: flex-end;
  }
  .nav-menu a {
    font-size: 0;
  }
  .nav-menu a[href="#home"]::before { content: "🏠"; font-size: 20px; }
  .nav-menu a[href="#about"]::before { content: "🔖"; font-size: 20px; }
  .nav-menu a[href="#mission"]::before { content: "🎯"; font-size: 20px; }
  .nav-menu a[href="#advantage"]::before { content: "⭐"; font-size: 20px; }
  .nav-menu a[href="#contact"]::before { content: "📩"; font-size: 20px; }
  
  /* 移动端语言选择器 - 简化版 */
  .lang-divider {
    display: none !important;
  }
  .lang-item {
    display: none !important;
  }
  .lang-item.mobile-visible {
    display: block !important;
  }
  .lang-btn {
    font-size: 12px !important;
    padding: 5px 12px;
    background: #f1f5f9;
    border-radius: 12px;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-block;
    font-weight: 500;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
  }
  .lang-btn:hover {
    background: #e2e8f0;
    transform: scale(1.05);
  }
  .lang-btn.active {
    background: #2563eb;
    color: white;
    box-shadow: 0 2px 6px rgba(37,99,235,0.3);
  }
  
  /* 添加语言切换提示 */
  .lang-item:first-of-type::after {
    content: " 🌐";
    font-size: 14px;
  }

  /* 手机顶部：只显示 重定义运动 + 标语 */
  .hero {
    background: #fff !important;
    padding: 40px 16px !important;
  }
  .hero .slogan {
    visibility: hidden !important;
    line-height: 1.4 !important;
  }
  .hero .slogan::after {
    content: "数据驱动运动 · 智能定义未来 · 加速文明进程";
    visibility: visible;
    display: block;
    font-size: 14px;
    color: #666;
    margin-top: 8px;
  }
}

/* 电脑端正常 */
@media (min-width: 769px) {
  .container {
    max-width: 960px;
    padding: 0 32px 120px;
  }
  .section {
    flex-direction: row;
    padding: 56px 60px;
    gap: 44px;
    margin-bottom: 40px;
  }
  .section-title {
    flex: 0 0 200px;
    margin-bottom: 0;
  }
  .advantage-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }
  .contact-content {
    flex-direction: row;
    gap: 44px;
  }
}