/* 全局重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Microsoft Yahei", sans-serif;
}
body {
    color: #333;
    background-color: #ffffff;
    line-height: 1.7;
}
ul {
    list-style: none;
}
a {
    text-decoration: none;
    color: inherit;
}
.container {
    width: 90%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 15px;
}

/* 导航栏 */
.header {
    background: #ffffff;
    box-shadow: 0 2px 8px rgba(0,60,20,0.1);
    position: sticky;
    top:0;
    z-index:99;
}
.nav-wrap {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height:70px;
}
/* Logo图片样式 PC端放大70% */
.logo img {
    height: 52px;
    width: auto;
    display: block;
    transform: scale(1.7);
    transform-origin: left center;
}
.nav-list {
    display: flex;
    gap: 32px;
}
.nav-list li a {
    font-size:16px;
    color:#205928;
    font-weight:500;
    transition: color 0.25s;
}
.nav-list li a.active,
.nav-list li a:hover {
    color:#279034;
}
.menu-btn {
    display: none;
    font-size:26px;
    color:#205928;
}
.top-space {
    height:20px;
}

/* Banner首页大图区域 */
.banner {
    background: linear-gradient(rgba(0,70,25,0.7), rgba(0,70,25,0.7)), url("banner-bg.jpg");
    background-size: cover;
    background-position:center;
    color:#fff;
    padding:100px 0;
    text-align:center;
}
.banner-text h1 {
    font-size:42px;
    margin-bottom:18px;
}
.banner-text p {
    font-size:18px;
    max-width:750px;
    margin:0 auto;
    opacity:0.95;
}

/* 标题模块 */
.title-box {
    text-align:center;
    margin:60px 0 35px;
}
.title-box h2 {
    font-size:30px;
    color:#205928;
    margin-bottom:10px;
}
.title-box p {
    color:#666;
    font-size:16px;
}

/* 产品卡片网格 */
.product-grid {
    display:grid;
    grid-template-columns: repeat(3, 1fr);
    gap:30px;
    margin-bottom:60px;
}
.product-card {
    background:#fff;
    border-radius:12px;
    box-shadow:0 3px 12px rgba(0,50,15,0.08);
    overflow:hidden;
    transition: transform 0.3s;
}
.product-card:hover {
    transform: translateY(-6px);
}
.product-img {
    height:190px;
    background-color:#eef7ee;
    display:flex;
    align-items:center;
    justify-content:center;
    color:#205928;
    font-size:15px;
}
.product-info {
    padding:22px;
}
.product-info h3 {
    color:#205928;
    font-size:18px;
    margin-bottom:12px;
}
.product-info p {
    color:#555;
    font-size:15px;
}

/* 页脚footer */
.footer {
    background:#1a4220;
    color:#e8f3e9;
    padding:50px 0 20px;
    margin-top:70px;
}
.footer-content {
    display:grid;
    grid-template-columns: repeat(3,1fr);
    gap:35px;
}
.footer-box h3 {
    font-size:19px;
    margin-bottom:16px;
}
.footer-box p {
    font-size:15px;
    opacity:0.9;
}
.copyright {
    text-align:center;
    margin-top:40px;
    padding-top:20px;
    border-top:1px solid #2c5c33;
    font-size:14px;
    opacity:0.8;
}
.copyright a:hover{
    color:#fff;
    text-decoration:underline;
}

/* 移动端适配 手机 */
@media (max-width:768px){
    .nav-list {
        display:none;
    }
    .menu-btn {
        display:block;
    }
    .banner-text h1 {
        font-size:28px;
    }
    .product-grid {
        grid-template-columns:1fr;
    }
    .footer-content {
        grid-template-columns:1fr;
    }
    /* 手机端logo缩放，防止溢出 */
    .logo img {
        transform: scale(1.35);
        transform-origin: left center;
    }
    /* 移动端菜单展开 */
    .nav-list.show {
        display: flex;
        flex-direction: column;
        position: absolute;
        top:70px;
        left:0;
        width:100%;
        background:#fff;
        box-shadow:0 4px 10px rgba(0,0,0,0.1);
        padding:20px 5%;
        gap:20px;
    }
}

/* 回到顶部按钮 */
.back-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 48px;
    height: 48px;
    background-color: #205928;
    color: #fff;
    border-radius: 50%;
    text-align: center;
    line-height: 48px;
    font-size: 22px;
    cursor: pointer;
    box-shadow: 0 3px 10px rgba(0,0,0,0.15);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 98;
}
.back-top.show {
    opacity: 1;
    visibility: visible;
}
.back-top:hover {
    background-color: #279034;
}

/* 图片懒加载占位样式 */
img.lazy {
    opacity: 0.25;
    transition: opacity 0.4s ease;
}
img.lazy.loaded {
    opacity: 1;
}