/* 全局样式 */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

body {
  line-height: 1.6;
  color: #333;
  background-color: #f5f5f5;
}

/* 头部导航 */
.header {
  background-color: #2c3e50;
  padding: 1rem 0;
}
.nav {
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  gap: 2rem;
}
.nav-link {
  color: white;
  text-decoration: none;
  padding: 0.5rem 1rem;
  border-radius: 4px;
}
.nav-link.active, .nav-link:hover {
  background-color: #34495e;
}

/* 容器 */
.container {
  max-width: 800px;
  margin: 2rem auto;
  padding: 0 1rem;
}

/* 首页英雄区 */
.hero {
  text-align: center;
  padding: 3rem 0;
  background-color: white;
  border-radius: 8px;
  margin-bottom: 2rem;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
.hero h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
  color: #2c3e50;
}

/* 卡片布局 */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
}
.card {
  background-color: white;
  padding: 1.5rem;
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
.card h3 {
  margin-bottom: 0.5rem;
  color: #2c3e50;
}

/* 按钮样式 */
.btn {
  display: inline-block;
  margin-top: 1rem;
  padding: 0.5rem 1.5rem;
  background-color: #3498db;
  color: white;
  text-decoration: none;
  border-radius: 4px;
}
.btn:hover {
  background-color: #2980b9;
}
.download-btn {
  background-color: #27ae60;
}
.download-btn:hover {
  background-color: #219a52;
}

/* 内容区 */
.content {
  background-color: white;
  padding: 2rem;
  border-radius: 8px;
  box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
.content h2 {
  margin-bottom: 1rem;
  color: #2c3e50;
}

/* 下载项 */
.download-item {
  margin: 2rem 0;
  padding: 1.5rem;
  border: 1px solid #e0e0e0;
  border-radius: 8px;
}

/* 页脚 */
.footer {
  text-align: center;
  padding: 2rem 0;
  color: #666;
  margin-top: 3rem;
}