/* 基础重置 */
* { margin: 0; padding: 0; box-sizing: border-box; }
body { font-family: 'Microsoft YaHei', sans-serif; background: #f5f7fa; color: #333; }
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
a { text-decoration: none; color: #0055a4; }
.btn { display: inline-block; padding: 10px 25px; border-radius: 4px; border: none; cursor: pointer; }
.btn-primary { background: #0055a4; color: #fff; }
.btn-secondary { background: #e6e6e6; color: #333; }
.btn-light { background: #fff; color: #0055a4; }

/* ===== 顶部导航 ===== */
.site-header { background: #fff; box-shadow: 0 2px 4px rgba(0,0,0,0.1); padding: 15px 0; position: sticky; top: 0; z-index: 100; }
.header-container { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; }
.logo img { height: 40px; }
.main-nav ul { display: flex; list-style: none; gap: 30px; }
.main-nav ul li a { color: #333; font-weight: 500; }
.main-nav ul li a:hover { color: #0055a4; }
.header-actions { display: flex; align-items: center; gap: 15px; flex-wrap: wrap; }
.customer-service { font-size: 14px; color: #666; }

/* ===== 底部 ===== */
.site-footer { background: #1a2332; color: #ccc; padding: 40px 0 20px; margin-top: 40px; }
.footer-container { display: grid; grid-template-columns: repeat(3, 1fr); gap: 40px; }
.footer-col h4 { color: #fff; margin-bottom: 15px; }
.footer-col ul { list-style: none; }
.footer-col ul li { margin-bottom: 8px; }
.footer-col ul li a { color: #ccc; }
.footer-col ul li a:hover { color: #fff; }
.footer-bottom { border-top: 1px solid #333; padding-top: 20px; margin-top: 30px; display: flex; justify-content: space-between; flex-wrap: wrap; }
.footer-links a { color: #ccc; margin: 0 10px; }

/* ===== 移动端固定按钮 ===== */
.mobile-fixed-buttons { display: none; position: fixed; bottom: 0; left: 0; right: 0; background: #fff; padding: 10px; box-shadow: 0 -2px 10px rgba(0,0,0,0.1); justify-content: space-around; z-index: 999; }
.mobile-fixed-buttons .btn { flex: 1; text-align: center; margin: 0 5px; }

/* ===== 响应式 ===== */
@media (max-width: 768px) {
    .header-container { flex-direction: column; gap: 15px; }
    .main-nav ul { gap: 15px; flex-wrap: wrap; justify-content: center; }
    .header-actions .btn { display: none; } /* 手机上隐藏顶部按钮 */
    .footer-container { grid-template-columns: 1fr; gap: 20px; }
    .footer-bottom { flex-direction: column; align-items: center; gap: 10px; }
    .mobile-fixed-buttons { display: flex; }
    .main-content { padding-bottom: 80px; } /* 为固定按钮留空间 */
}

@media (max-width: 480px) {
    .main-nav ul { gap: 10px; font-size: 14px; }
    .hero-section { padding: 40px 0; }
    .hero-section h1 { font-size: 24px; }
}