:root{
    --primary-color:#FEBF1D;
    --font-color:#fff;
    --bg-color:#fff;
    --nav-height:70px;
}

/* ===== 固定 Header ===== */
header {
    position: fixed;
    top: 0;
    right: 0;
    left: 0;
    height: var(--nav-height);
    display: flex;
    align-items: center;
    padding: 0 20px;
    background: rgba(255,255,255,0.95);
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    z-index: 1000;
    gap: 40px;
}

.logo{
    display:flex;
    align-items:center;
    gap:10px;
}
.logo-img{width:50px;height:50px;object-fit:contain;}
.logo-text h1{font-size:20px;color:var(--primary-color);margin:0;}
.logo-text span{font-size:12px;color:#666;}

/* nav */
nav {
    flex: 1;
    background-color: #fff;
}
nav ul{
    display:flex;
    list-style:none;
    gap:20px;
    margin:0;
    padding:0;
    justify-content:flex-start;
}
nav ul li {
    padding: 16px 0;
}
nav ul li+li {
    border-top: 1px solid #eee;
}
nav a{
    text-decoration:none;
    color:#333;
    font-weight:500;
    padding:8px 12px;
    border-radius:4px;
    transition:all 0.3s;
}
nav a:hover, nav a.active{
    color:#fff;
    background: var(--primary-color);
}

/* 汉堡按钮 */
.menu-toggle{
    display:none;
    font-size:28px;
    cursor:pointer;
}

/* 语言切换 */
.lang-toggle{
    margin-left:auto;
    font-size:20px;
    color:var(--primary-color);
    cursor:pointer;
    z-index:1500;
    transition: transform 0.3s;
}
.lang-toggle:hover{ transform: scale(1.2); }

.lang-select{
    position: absolute;
    top:50px;
    right:20px;
    display: none;
    flex-direction: column;
    background:#fff;
    padding:10px;
    border-radius:12px;
    box-shadow:0 4px 12px rgba(0,0,0,0.15);
    gap:8px;
    z-index:1500;
    min-width:100px;
}
.lang-btn{
    background:#f5f5f5;
    border:none;
    padding:8px 14px;
    border-radius:8px;
    cursor:pointer;
    font-weight:500;
    text-align:center;
    transition: all 0.2s;
}
.lang-btn:hover{ background:var(--primary-color); color:#fff; }
.lang-btn.active{ background:var(--primary-color); color:#fff; }

/* ===== 内容区顶部空白 ===== */
body > section, #home, #products, #partners, #consulting, #contact {
    padding-top: var(--nav-height);
    box-sizing: border-box;
}

/* ===== 首页 ===== */
#home {
    width: 100%;
    height: calc(100vh - var(--nav-height));
    min-height: calc(100svh - var(--nav-height));
    background: url('./img/fJpCBVYoE.jpg') center/cover no-repeat;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    position: relative;
    text-align: center;
    color: #fff;
}
.home-overlay{
    background: rgba(0,0,0,0.4);
    padding: 40px 20px;
    border-radius: 10px;
    display: flex;
    flex-direction: column !important;
    align-items: center;
}
#home h2{font-size:48px;margin-bottom:30px;text-shadow:0 2px 6px rgba(0,0,0,0.5);}
.download-buttons{
    display:flex;
    gap:20px;
    flex-wrap:wrap;
    justify-content:center;
}
.download-buttons a{
    background:var(--primary-color);
    color:#fff;
    padding:14px 28px;
    text-decoration:none;
    border-radius:5px;
    transition:all 0.3s;
}
.download-buttons a:hover{
    background:#e6a300;
    transform:scale(1.05);
}

/* ===== 产品页 ===== */
#products{
    padding: 60px 20px 50px;
    max-width: 1200px;
    margin:0 auto;
}
.product-tabs{
    display:flex;
    gap:20px;
    margin-bottom:20px;
    border-bottom:2px solid #eee;
}
.product-tabs button{
    background:none;
    border:none;
    padding:10px 0;
    font-size:18px;
    cursor:pointer;
    color:#666;
    transition:color 0.3s,border-bottom 0.3s;
}
.product-tabs button.active{
    color:var(--primary-color);
    border-bottom:3px solid var(--primary-color);
    font-weight:bold;
}
.product-content{
    display:flex;
    flex-wrap:wrap;
    gap:20px;
}
.product-content img{
    max-width:100%;
    border-radius:8px;
    flex:1 1 300px;
}
.product-text{
    flex:1 1 300px;
    display:flex;
    flex-direction: column;
    justify-content: flex-start; /* 解决标题与描述距离太大 */
    gap: 10px; /* 标题与描述间距 */
}
.product-text h3{
    margin:0;
}
.product-text #product-desc{
    margin:0;
}

/* 步骤 */
.product-steps{
    display:flex;
    gap:20px;
    margin-top:20px;
    flex-wrap:wrap;
}
.product-steps .step{
    display:flex;
    flex-direction:column;
    align-items:center;
    flex:1 1 150px;
}
.product-steps .step img{
    max-width:150px;
    border-radius:5px;
    margin-bottom:10px;
}
.product-steps .step p{
    text-align:center;
    font-size:14px;
    color:#333;
}

/* ===== 合作站点 iframe ===== */
#partners{
    width:100%;
    height: calc(100vh - var(--nav-height));
    min-height: calc(100svh - var(--nav-height));
    display:flex;
    justify-content:center;
    align-items:center;
}
#partners iframe{
    width:100%;
    height:100%;
    border:0;
}

/* ===== 视频弹窗 ===== */
#consulting{padding:100px 20px;max-width:1200px;margin:0 auto;}
.video-grid{display:flex;flex-wrap:wrap;gap:20px;justify-content:flex-start;}
.video-card{width:300px;cursor:pointer;position:relative;transition:transform 0.3s;}
.video-card:hover{transform:scale(1.03);}
.video-card img{width:100%;border-radius:8px;}
.video-card .title{margin-top:5px;font-weight:bold;}
.video-card .date{font-size:12px;color:#666;}
.modal{position:fixed;top:0;left:0;width:100%;height:100%;background:rgba(0,0,0,0.7);display:none;justify-content:center;align-items:center;z-index:2000;opacity:0;transition:opacity 0.3s ease;}
.modal.show{display:flex;opacity:1;}
.modal-content{position:relative;width:90%;max-width:800px;background:#000;border-radius:8px;overflow:hidden;}
.modal-content video{width:100%;height:auto;display:block;}
.modal-close{position:absolute;top:10px;right:10px;color:#fff;font-size:28px;cursor:pointer;background:rgba(0,0,0,0.4);padding:2px 6px;border-radius:50%;}

/* ===== 联系我们 ===== */
#contact{padding:100px 20px;max-width:800px;margin:0 auto;display:grid;gap:30px;}
.contact-item{display:flex;gap:20px;align-items:center;}
.contact-item img{width:150px;height:150px;object-fit:contain;cursor:pointer;transition:transform 0.3s;}
.contact-item img:hover{transform:scale(1.1);}
.contact-item div{display:flex;flex-direction:column;gap:5px;}

/* ===== 响应式 ===== */
@media(max-width:768px){
    header{
        flex-direction: column;
        align-items: flex-start;
        height: 50px;
        padding:10px 20px;
    }
    nav{ width:100%; margin-top:10px; }
    nav ul{ flex-direction: column; display:none; gap:10px; width:100%; }
    nav ul.show{ display:flex; }
    .menu-toggle{ display: block; position:absolute; top:15px; right:20px; }
    .lang-toggle{ position:absolute; top:20px; right:56px; }

    #home{
        height: calc(100svh - var(--nav-height));
    }
    #home h2{font-size:32px;}
    .download-buttons a{padding:12px 20px;font-size:14px;}
    .product-content{flex-direction:column;align-items:center;text-align:center;}
    .video-grid{justify-content:center;}
}