*{margin:0;padding:0;box-sizing:border-box;font-family:'Segoe UI',sans-serif;scroll-behavior:smooth}
body{background:#f8f9fa;color:#212529}
#main {
    min-height:calc(100vh - 216px); /* 216px是header和footer的总高度 */
}
/* .sec{padding:30px 0;background:#fff}
.sec-gray{background:#f1f5f9}
.sec-title{text-align:center;margin-bottom:30px}
.sec-title h2{font-size:38px;color:#0f172a} */

/* 自定义卡片样式
/* .card{border:none;box-shadow:0 3px 15px rgba(0,0,0,0.06);transition:0.3s}
.card img{object-fit:cover}
.card-title{color:#0f172a;font-size:20px;margin-bottom:10px}
.card-text{color:#475569} */


/* 底部 */
.footer{background:#1e293b;color:#e2e8f0;text-align:center;padding:45px 0;}

.hover-gray:hover{background:#d7d7d7}
/* 产品卡片图片覆盖层hover效果 */
.card .image-overlay{border-radius: 6px 6px 0 0;}
.card:hover .image-overlay{opacity:1 !important;}