ul,ol{list-style:none;}
a{text-decoration:none;transition:all 0.24s ease;}
/* 主导航外层 */
.main-header{
    position:sticky;
    top:0;
    z-index:9999;
    background:#ffffff;
    transition: background 0.3s ease, backdrop-filter 0.3s ease, box-shadow 0.3s ease;
    will-change: background, box-shadow;
}
.main-header.scrolled{
    background:rgba(255,255,255,0.82);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    box-shadow:0 4px 16px rgba(20,75,140,0.1);
}
.nav-wrap{
    max-width:1200px;
    margin:0 auto;
    padding:0 24px;
    height:92px;
    display:flex;
    justify-content:space-between;
    align-items:center;
}
/* Logo区域 图片+文字标语 */
.logo-area{
    display:flex;
    align-items:center;
    gap:14px;
}
.logo-area img{
    height:56px;
    border-radius:4px;
}
.logo-brand{
    font-size:18px;
    font-weight:700;
    color:#144b8c;
    letter-spacing:0.5px;
}
.logo-slogan{
    font-size:14px;
    color:#5578a3;
    margin-top:2px;
}
/* PC主导航菜单 */
.nav-pc{
    display:flex;
    align-items:center;
    gap:44px;
}
.nav-pc > li{
    position:relative;
    /* 修复hover间隙：扩大hover热区 */
    padding-bottom:14px;
}
.nav-pc > li > a{
    color:#222;
    font-size:16px;
    font-weight:500;
    padding:12px 0;
    display:block;
    position:relative;
    transition: all 0.25s ease;
}
/* 下划线动画 */
.nav-pc > li > a::after{
    content:"";
    position:absolute;
    left:0;
    bottom:0;
    width:0;
    height:2px;
    background:#144b8c;
    border-radius:2px;
    transition: width 0.28s ease;
}
/* 当前栏目高亮 */
.nav-pc > li > a.active{
    color:#144b8c;
    font-weight:600;
}
.nav-pc > li > a.active::after{
    width:100%;
}
.nav-pc > li > a:hover{
    color:#144b8c;
    transform: translateY(-2px);
}
.nav-pc > li > a:hover::after{
    width:100%;
}
/* 下拉三角旋转动画 */
.nav-pc > li > a .arrow{
    display:inline-block;
    transition: transform 0.24s ease;
}
.nav-pc > li:hover > a .arrow{
    transform: rotate(180deg);
}
/* 产品下拉面板 PC半透明毛玻璃，淡入弹出动画 */
.submenu{
    position:absolute;
    left:0;
    top:calc(100% + 8px);
    background:rgba(255,255,255,0.9);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    width:min(620px, calc(100vw - 48px));
    padding:20px;
    box-shadow:0 8px 24px rgba(20,75,140,0.12);
    border-radius:0 0 12px 12px;
    opacity:0;
    transform: translateY(-8px);
    display:block;
    pointer-events:none;
    transition: opacity 0.28s ease, transform 0.28s ease;
}
.submenu-list{
    display:grid;
    grid-template-columns:repeat(3,1fr);
    gap:16px;
}
.submenu-item{
    display:flex;
    flex-direction:column;
    align-items:center;
    padding:12px 8px;
    border-radius:8px;
    transition: all 0.24s ease;
    border:1px solid transparent;
}
.submenu-item:hover{
    background:#f7faff;
    border-color:#dceaf7;
    transform: translateY(-4px);
    box-shadow:0 4px 12px rgba(20,75,140,0.08);
}
.submenu-item img{
    width:80px;
    height:80px;
    object-fit:cover;
    border-radius:6px;
    margin-bottom:8px;
}
.submenu-item a{
    text-align:center;
    color:#333;
    font-size:14px;
}
.submenu-item a:hover{
    color:#144b8c;
}
.nav-pc li:hover .submenu{
    opacity:1;
    transform: translateY(0);
    pointer-events:auto;
}
/* 移动端菜单 */
#menu-check{display:none;}
.hamburger{
    display:none;
    color:#144b8c;
    font-size:32px;
    cursor:pointer;
    user-select:none;
    transition: transform 0.24s ease;
}
.hamburger:active{
    transform: scale(0.9);
}
@media(max-width:768px){
    .nav-wrap{
        height:82px;
        padding:0 16px;
    }
    .logo-area img{
        height:46px;
    }
    .logo-brand{
        font-size:16px;
    }
    .logo-slogan{
        font-size:12px;
    }
    .nav-pc{
        position:absolute;
        left:0;
        top:82px;
        width:100%;
        background:#fff;
        flex-direction:column;
        padding:24px 16px;
        display:flex;
        gap:0;
        box-shadow:0 4px 10px rgba(0,0,0,0.08);
        opacity:0;
        transform: translateY(-10px);
        pointer-events:none;
        transition: opacity 0.28s ease, transform 0.28s ease;
    }
    #menu-check:checked ~ .nav-pc{
        opacity:1;
        transform: translateY(0);
        pointer-events:auto;
    }
    .nav-pc li{
        width:100%;
        padding-bottom:0;
    }
    .nav-pc li a{
        padding:16px 0;
        border-bottom:1px solid #eee;
        font-size:16px;
    }
    /*手机端直接隐藏产品子菜单 */
    .submenu{
        display:none !important;
    }
    .hamburger{
        display:block;
    }
}