/* 导航当前项下划线 — 全站统一（对齐设计稿图三） */
.nav-list li a.active {
    font-weight: bold;
}

.nav-list li a.active::after {
    content: "";
    position: absolute;
    bottom: 6px;
    left: 50%;
    transform: translateX(-50%);
    width: 32px;
    height: 3px;
    border-radius: 3px;
    background: #00b8d4;
    transition: background 0.35s ease;
}

/* 青色顶栏：下划线为白色短圆角条 */
.site-header.is-scrolled .nav-list li a.active::after,
body.page-list .nav-list li a.active::after,
body.page-detail .nav-list li a.active::after {
    background: #fff;
}

/* 解决方案下拉箭头 */
.nav-dropdown-arrow {
    display: inline-block;
    width: auto;
    height: 8px;
    margin-left: 5px;
    vertical-align: middle;
    transition: transform 0.2s ease;
    filter: brightness(0);
}

.site-header.is-scrolled .nav-dropdown-arrow,
body.page-list .nav-dropdown-arrow,
body.page-detail .nav-dropdown-arrow {
    filter: none;
}

.nav-dropdown.open .nav-dropdown-arrow {
    transform: rotate(180deg);
}

/* 桌面端 hover 展开下拉（与 JS 配合，无 JS 时仍可用） */
@media (min-width: 769px) {
    .nav-dropdown:hover .nav-dropdown-menu {
        opacity: 1;
        visibility: visible;
    }

    .nav-dropdown:hover .nav-dropdown-arrow {
        transform: rotate(180deg);
    }
}