/* 全局重置 & 基础样式 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Microsoft YaHei", Arial, sans-serif;
  scroll-behavior: smooth;
}

body {
  line-height: 1.6;
  color: #333;
  background-color: #f8f9fa;
}

/* 必应SEO优化：语义化容器 */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

/* 固定长条形导航栏（核心要求） */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 70px;
  background: #ffffff;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  z-index: 999;
  transition: all 0.3s ease;
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
}

.logo img {
  height: 45px;
  width: auto;
  object-fit: contain;
}

.logo-text {
  font-size: 22px;
  font-weight: bold;
  color: #0088cc;
}

/* 导航菜单 */
.nav-menu {
  display: flex;
  list-style: none;
  gap: 30px;
}

.nav-menu a {
  text-decoration: none;
  font-size: 16px;
  color: #333;
  font-weight: 500;
  transition: color 0.3s;
}

.nav-menu a:hover {
  color: #0088cc;
}

.download-btn {
  padding: 10px 20px;
  background: #0088cc;
  color: #fff !important;
  border-radius: 5px;
}

.download-btn:hover {
  background: #0077b3 !important;
}

/* 主体内容间距（避开固定导航栏） */
main {
  margin-top: 70px;
}

/* 板块通用样式 */
.section {
  padding: 80px 0;
  min-height: 600px;
  display: flex;
  align-items: center;
}

.section-white {
  background: #fff;
}

.section-gray {
  background: #f8f9fa;
}

.section-title {
  font-size: 36px;
  text-align: center;
  margin-bottom: 50px;
  color: #222;
}

.section-subtitle {
  font-size: 18px;
  text-align: center;
  color: #666;
  margin-bottom: 30px;
}

/* 首页展示区 */
.hero {
  height: calc(100vh - 70px);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: linear-gradient(135deg, #e3f2fd 0%, #f5f9ff 100%);
}

.hero-img {
  max-width: 600px;
  width: 100%;
  margin: 30px auto;
  border-radius: 10px;
  box-shadow: 0 5px 20px rgba(0,136,204,0.15);
}

.hero h1 {
  font-size: 48px;
  color: #222;
  margin-bottom: 20px;
}

.hero p {
  font-size: 20px;
  color: #555;
  max-width: 800px;
  margin: 0 auto 40px;
}

.hero-buttons {
  display: flex;
  gap: 20px;
  justify-content: center;
}

.btn {
  padding: 15px 40px;
  border-radius: 5px;
  text-decoration: none;
  font-size: 18px;
  font-weight: 500;
  transition: all 0.3s;
}

.btn-primary {
  background: #0088cc;
  color: #fff;
}

.btn-primary:hover {
  background: #0077b3;
}

/* 内容网格布局 */
.grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 30px;
  margin-top: 40px;
}

.card {
  background: #fff;
  padding: 30px;
  border-radius: 10px;
  box-shadow: 0 3px 15px rgba(0,0,0,0.05);
  text-align: center;
  transition: transform 0.3s;
}

.card:hover {
  transform: translateY(-5px);
}

.card img {
  max-width: 100%;
  height: 180px;
  object-fit: cover;
  border-radius: 5px;
  margin-bottom: 20px;
}

.card h3 {
  font-size: 22px;
  margin-bottom: 15px;
  color: #0088cc;
}

/* 页脚 */
.footer {
  background: #222;
  color: #fff;
  padding: 50px 0 20px;
  text-align: center;
}

.footer p {
  margin-bottom: 10px;
}

/* 响应式适配 */
@media (max-width: 768px) {
  .nav-menu {
    gap: 15px;
  }
  .grid {
    grid-template-columns: 1fr;
  }
  .hero h1 {
    font-size: 32px;
  }
}