/* ========== 二级菜单：移动端 dropdown，PC 保持横排 tab ========== */
.subnav-mobile {
    display: none;
}

.subnav-desktop {
    display: flex;
}

@media (max-width: 1023px) {
    .subnav-mobile {
        display: block;
    }

    .subnav-desktop {
        display: none;
    }
}

.subnav-dropdown {
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height 0.35s ease, opacity 0.25s ease;
}

.subnav-dropdown.is-open {
    max-height: 400px;
    opacity: 1;
}

.subnav-trigger .arrow {
    transition: transform 0.3s ease;
    transform: translateY(-50%);
    top: 50%;
}

.subnav-trigger[aria-expanded="true"] .arrow {
    transform: translateY(-50%) rotate(180deg);
}

/* ========== 成果落地：移动端网格卡片，PC 恢复手风琴交互 ========== */
.accordion-group {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    width: 100%;
}

@media (min-width: 1024px) {
    .accordion-group {
        display: flex;
        height: 600px;
        gap: 20px;
    }

    .accordion-card {
        flex: 1 1 0%;
        min-width: 0;
        transition: flex 0.6s cubic-bezier(0.4, 0, 0.2, 1);
        cursor: pointer;
        position: relative;
    }

    .accordion-card:hover {
        flex: 3 1 0%;
    }
}