/* 全局重置 + 必应SEO友好基础样式 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  scroll-behavior: smooth; /* 锚点平滑滚动 */
}

/* 页面基础样式 */
body {
  line-height: 1.6;
  color: #333;
  background-color: #f8f9fa;
}

/* 固定导航栏（核心：锚点跳转+页面导航） */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: #ffffff;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  z-index: 999;
  padding: 15px 0;
  transition: all 0.3s ease;
}
.navbar.scrolled {
  background: #25d366; /* WhatsApp官方绿 */
}
.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 20px;
}
.logo {
  font-size: 24px;
  font-weight: bold;
  color: #25d366;
  text-decoration: none;
}
.navbar.scrolled .logo {
  color: #fff;
}
.nav-menu {
  display: flex;
  list-style: none;
  gap: 30px;
}
.nav-menu a {
  text-decoration: none;
  color: #333;
  font-size: 16px;
  font-weight: 500;
  transition: 0.3s;
}
.navbar.scrolled .nav-menu a {
  color: #fff;
}
.nav-menu a:hover {
  color: #128c7e !important;
}

/* 通用容器 */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* 大横幅样式（主页专属，超大尺寸） */
.hero-banner {
  width: 100%;
  height: 100vh; /* 全屏高度大横幅 */
  background: url('../631599/banner.png') no-repeat center center;
  background-size: cover;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  color: white;
  margin-top: 80px;
  position: relative;
}
.hero-banner::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0,0,0,0.4);
}
.hero-content {
  position: relative;
  z-index: 2;
  max-width: 800px;
  padding: 20px;
}
.hero-content h1 {
  font-size: 52px;
  margin-bottom: 20px;
  line-height: 1.2;
}
.hero-content p {
  font-size: 20px;
  margin-bottom: 30px;
}
.btn {
  display: inline-block;
  padding: 15px 40px;
  background: #25d366;
  color: white;
  text-decoration: none;
  border-radius: 50px;
  font-size: 18px;
  font-weight: bold;
  transition: 0.3s;
  border: none;
  cursor: pointer;
}
.btn:hover {
  background: #128c7e;
  transform: translateY(-3px);
}

/* 长页面通用区块样式 */
.section {
  padding: 100px 0;
}
.section-title {
  text-align: center;
  font-size: 36px;
  color: #333;
  margin-bottom: 60px;
  position: relative;
}
.section-title::after {
  content: '';
  width: 80px;
  height: 4px;
  background: #25d366;
  display: block;
  margin: 15px auto;
}

/* 卡片布局 */
.card-group {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
}
.card {
  background: white;
  border-radius: 15px;
  overflow: hidden;
  box-shadow: 0 5px 15px rgba(0,0,0,0.05);
  transition: 0.3s;
}
.card:hover {
  transform: translateY(-10px);
}
.card img {
  width: 100%;
  height: 220px;
  object-fit: cover;
}
.card-body {
  padding: 25px;
}
.card-body h3 {
  font-size: 22px;
  margin-bottom: 15px;
  color: #333;
}
.card-body p {
  color: #666;
  font-size: 15px;
}

/* 下载专区样式 */
.download-section {
  background: #e9f5ef;
}
.download-card {
  text-align: center;
  padding: 40px;
}
.download-card img {
  width: 120px;
  height: 120px;
  margin: 0 auto 20px;
}

/* 页脚 */
.footer {
  background: #333;
  color: white;
  padding: 60px 0 20px;
}
.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 40px;
  margin-bottom: 40px;
}
.footer-col h4 {
  font-size: 18px;
  margin-bottom: 20px;
  color: #25d366;
}
.footer-col ul {
  list-style: none;
}
.footer-col ul li {
  margin-bottom: 10px;
}
.footer-col a {
  color: #ccc;
  text-decoration: none;
}
.footer-col a:hover {
  color: #25d366;
}
.copyright {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid #555;
  color: #ccc;
}

/* 响应式适配 */
@media (max-width: 768px) {
  .hero-content h1 {
    font-size: 32px;
  }
  .nav-menu {
    gap: 15px;
  }
  .section {
    padding: 60px 0;
  }
}