/* 全局重置 + 基础样式 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Microsoft YaHei", Arial, sans-serif;
}
html {
  scroll-behavior: smooth; /* 锚点平滑跳转 */
}
body {
  line-height: 1.6;
  color: #333;
  background-color: #f8f9fa;
}
img {
  max-width: 100%;
  height: auto;
  display: block;
}
a {
  text-decoration: none;
  color: inherit;
}
ul {
  list-style: none;
}
.container {
  width: 92%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 15px;
}

/* 固定导航栏（SEO+锚点核心） */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 70px;
  background: #fff;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  z-index: 999;
}
.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}
.logo {
  font-size: 24px;
  font-weight: bold;
  color: #0066cc;
}
.nav-menu {
  display: flex;
  gap: 30px;
}
.nav-menu a {
  font-size: 16px;
  font-weight: 500;
  color: #333;
  padding: 8px 0;
  transition: 0.3s;
}
.nav-menu a:hover, .nav-menu a.active {
  color: #0066cc;
  border-bottom: 2px solid #0066cc;
}

/* 页面顶部间距（适配固定导航栏） */
.section {
  padding: 100px 0 60px;
  min-height: 100vh;
}
.small-section {
  padding: 60px 0;
}

/* 标题样式（SEO层级） */
.h1-title {
  font-size: 36px;
  color: #222;
  text-align: center;
  margin-bottom: 40px;
  line-height: 1.3;
}
.h2-title {
  font-size: 28px;
  color: #222;
  margin-bottom: 25px;
}
.h3-title {
  font-size: 22px;
  color: #333;
  margin-bottom: 15px;
}

/* 按钮样式 */
.btn {
  display: inline-block;
  padding: 12px 30px;
  background: #0066cc;
  color: #fff;
  border-radius: 5px;
  font-size: 16px;
  transition: 0.3s;
  border: none;
  cursor: pointer;
  text-align: center;
}
.btn:hover {
  background: #0052aa;
}
.btn-success {
  background: #28a745;
}
.btn-success:hover {
  background: #218838;
}

/* 卡片布局 */
.card-group {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 30px;
  margin-top: 40px;
}
.card {
  background: #fff;
  padding: 25px;
  border-radius: 10px;
  box-shadow: 0 3px 15px rgba(0,0,0,0.05);
  transition: 0.3s;
}
.card:hover {
  transform: translateY(-5px);
}
.card img {
  border-radius: 8px;
  margin-bottom: 20px;
}

/* Banner样式 */
.banner {
  height: 500px;
  display: flex;
  align-items: center;
  background: linear-gradient(90deg, #e6f4ff, #f5f9ff);
  margin-top: 70px;
}
.banner-content {
  max-width: 600px;
}
.banner h1 {
  font-size: 42px;
  margin-bottom: 20px;
  color: #222;
}
.banner p {
  font-size: 18px;
  margin-bottom: 30px;
  color: #555;
}
.banner-img {
  width: 400px;
}

/* 下载页专属样式 */
.download-card {
  text-align: center;
  padding: 40px 20px;
}
.download-card img {
  width: 80px;
  margin: 0 auto 20px;
}
.system-info {
  color: #666;
  margin: 10px 0 20px;
  font-size: 14px;
}

/* 底部 */
.footer {
  background: #222;
  color: #fff;
  padding: 40px 0 20px;
  margin-top: 40px;
}
.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 30px;
  margin-bottom: 30px;
}
.footer-bottom {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid #444;
}