* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  color: #333;
  line-height: 1.7;
  background: #fff;
}

.container { max-width: 1100px; margin: 0 auto; padding: 0 20px; }

/* 顶部导航 */
.site-header {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255, 255, 255, 0.96);
  box-shadow: 0 1px 6px rgba(0, 0, 0, 0.08);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.logo { font-size: 22px; font-weight: 700; color: #1e5fa8; text-decoration: none; }
.nav a {
  color: #444; text-decoration: none; margin-left: 28px; font-size: 15px;
  transition: color 0.2s;
}
.nav a:hover { color: #1e5fa8; }
.nav-toggle {
  display: none; border: none; background: none; font-size: 24px;
  cursor: pointer; color: #444;
}

/* 首屏 */
.hero {
  background: linear-gradient(135deg, #1e5fa8 0%, #3a8fd8 60%, #6fc3ff 100%);
  color: #fff; text-align: center; padding: 110px 20px 120px;
}
.hero h1 { font-size: 46px; letter-spacing: 4px; margin-bottom: 18px; }
.hero .slogan { font-size: 18px; opacity: 0.92; margin-bottom: 36px; }
.btn {
  display: inline-block; background: #fff; color: #1e5fa8;
  padding: 12px 44px; border-radius: 30px; text-decoration: none;
  font-size: 16px; font-weight: 600; transition: transform 0.2s;
}
.btn:hover { transform: translateY(-2px); }

/* 通用区块 */
.section { padding: 70px 0; }
.section-alt { background: #f5f9fd; }
.section-title {
  text-align: center; font-size: 30px; color: #1e5fa8;
  margin-bottom: 14px;
}
.section-title::after {
  content: ""; display: block; width: 52px; height: 3px;
  background: #3a8fd8; margin: 14px auto 0; border-radius: 2px;
}
.section-text {
  max-width: 780px; margin: 26px auto 0; text-align: center;
  color: #555; font-size: 16px;
}

/* 卡片 */
.cards {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 24px; margin-top: 40px;
}
.card {
  background: #fff; border-radius: 10px; padding: 30px 24px;
  box-shadow: 0 4px 16px rgba(30, 95, 168, 0.08);
  transition: transform 0.25s, box-shadow 0.25s;
}
.card:hover { transform: translateY(-6px); box-shadow: 0 10px 26px rgba(30, 95, 168, 0.15); }
.card h3 { color: #1e5fa8; font-size: 19px; margin-bottom: 10px; }
.card p { color: #666; font-size: 14px; }

/* 联系 */
.contact-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 24px; margin-top: 40px;
}
.contact-item {
  background: #fff; border-radius: 10px; padding: 26px 20px;
  box-shadow: 0 4px 16px rgba(30, 95, 168, 0.08); text-align: center;
}
.contact-item h3 { color: #1e5fa8; font-size: 17px; margin-bottom: 8px; }
.contact-item p { color: #555; font-size: 15px; }

/* 页脚 */
.site-footer {
  background: #1b3a5c; color: #bcd2e8; text-align: center;
  padding: 30px 20px; font-size: 14px;
}
.site-footer a { color: #bcd2e8; text-decoration: none; }
.site-footer a:hover { color: #fff; }
.site-footer p { margin: 4px 0; }

/* 移动端 */
@media (max-width: 720px) {
  .hero h1 { font-size: 32px; }
  .nav-toggle { display: block; }
  .nav {
    display: none; position: absolute; top: 64px; left: 0; right: 0;
    background: #fff; flex-direction: column; padding: 10px 0;
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.08);
  }
  .nav.open { display: flex; }
  .nav a { margin: 10px 24px; }
  .header-inner { position: relative; }
}