* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Microsoft YaHei", sans-serif;
}

.container {
  width: 1200px;
  margin: 0 auto;
  padding: 0 15px;
}

/* 头部导航 */
.header {
  background: #222;
  color: #fff;
  padding: 20px 0;
  position: sticky;
  top: 0;
  z-index: 99;
}

.header .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 24px;
  font-weight: bold;
  color: #409eff;
}

.nav a {
  color: #fff;
  text-decoration: none;
  margin-left: 30px;
  font-size: 16px;
}

.nav a:hover,
.nav a.active {
  color: #409eff;
}

/* banner */
.banner {
  height: 500px;
  background: #409eff;
  color: #fff;
  display: flex;
  align-items: center;
  text-align: center;
}

.banner h1 {
  font-size: 42px;
  margin-bottom: 20px;
}

.banner p {
  font-size: 18px;
  margin-bottom: 30px;
}

.btn {
  display: inline-block;
  padding: 12px 30px;
  background: #fff;
  color: #409eff;
  text-decoration: none;
  border-radius: 5px;
  font-weight: bold;
}

/* 通用标题 */
h2 {
  text-align: center;
  font-size: 32px;
  margin-bottom: 40px;
  color: #333;
  position: relative;
}

h2::after {
  content: "";
  width: 60px;
  height: 3px;
  background: #409eff;
  position: absolute;
  left: 50%;
  bottom: -10px;
  transform: translateX(-50%);
}

/* 关于我们 */
.about {
  padding: 80px 0;
  background: #f5f5f5;
}

.about-content {
  max-width: 900px;
  margin: 0 auto;
  line-height: 1.8;
  font-size: 16px;
  color: #666;
}

.about-content p {
  margin-bottom: 20px;
}

/* 产品 */
.product {
  padding: 80px 0;
}

.product-list {
  display: flex;
  flex-wrap: wrap;
  gap: 30px;
  justify-content: center;
}

.product-item {
  width: 260px;
  padding: 30px 20px;
  border: 1px solid #eee;
  border-radius: 8px;
  text-align: center;
}

.product-item h3 {
  font-size: 20px;
  margin-bottom: 15px;
  color: #333;
}

.product-item p {
  color: #666;
}

/* 新闻 */
.news {
  padding: 80px 0;
  background: #f5f5f5;
}

.news-item {
  max-width: 900px;
  margin: 0 auto 20px;
  padding: 20px;
  background: #fff;
  border-left: 4px solid #409eff;
}

.news-item h3 {
  font-size: 18px;
  margin-bottom: 10px;
  color: #333;
}

.news-item p {
  color: #666;
}

/* 联系我们 */
.contact {
  padding: 80px 0;
}

.contact p {
  text-align: center;
  font-size: 18px;
  margin-bottom: 15px;
  color: #333;
}

/* 底部 */
.footer {
  background: #222;
  color: #fff;
  text-align: center;
  padding: 30px 0;
}