/* ─── CSS Variables ─────────────────────────────── */
    :root {
        --brand:       #1e4fb5;
        --brand-link:  rgb(34, 95, 201);   /* 下拉分组标题 / 分类标题色 */
        --nav-h:       68px;
        --radius:      8px;
        --shadow:      0 8px 30px rgba(0,0,0,.12);
        --transition:  color 250ms ease, background 250ms ease, opacity 250ms ease,
        transform 250ms ease, box-shadow 250ms ease;
    }

    /* ─── Navbar Wrapper ────────────────────────────── */
    #pc-nav {
        position: fixed;
        top: 0; left: 0; right: 0;
        z-index: 1000;
        background: var(--brand);
        /* 底部微妙渐变线，层次感 */
        border-bottom: 1px solid rgba(255,255,255,.12);
        transition: box-shadow 250ms ease;
    }
    #pc-nav a{
        text-decoration: none !important;
    }

    .pc_nav-inner {
        display: flex;
        align-items: center;
        width: 100%;
        max-width: 1440px;
        margin: 0 auto;
        height: var(--nav-h);
        padding: 0 24px;
    }

    /* ─── Logo ──────────────────────────────────────── */
    .pc_nav-logo { flex-shrink: 0; margin-right: 48px; }
    .pc_nav-logo img { height: 34px; width: auto; display: block; }

    /* ─── Primary Menu ──────────────────────────────── */
    .pc_nav-menu {
        display: flex;
        align-items: center;
        justify-content: center;
        flex: 1;
        gap: 48px;          /* 加大间距，呼吸感 */
        margin: 0;
    }

    @media (max-width: 1380px) {
        .pc_nav-menu { gap: 28px; }
        .pc_nav-item > .pc_nav-link { font-size: 14px; }
        .pc_nav-logo img { height: 30px; }
    }

    /* ─── Level-1 Item ──────────────────────────────── */
    .pc_nav-item {
        position: relative;
        height: var(--nav-h);
        display: flex;
        align-items: center;
    }

    .pc_nav-item > .pc_nav-link {
        position: relative;
        display: flex;
        align-items: center;
        gap: 6px;
        font-family: 'Montserrat', sans-serif;
        font-style: normal;
        font-weight: bold;
        font-size: 15px;
        line-height: 1;
        color: #fff;
        letter-spacing: .04em;
        white-space: nowrap;
        padding: 0 2px;
        transition: opacity 250ms ease;
        cursor: pointer;
        user-select: none;
    }
    /* hover：轻微淡化，克制优雅 */
    .pc_nav-item > .pc_nav-link:hover { opacity: .70; }

    /* 一级箭头：更小更轻 */
    .pc_nav-link .arrow {
        display: inline-block;
        width: 7px; height: 7px;
        border-right: 1.5px solid rgba(255,255,255,.7);
        border-bottom: 1.5px solid rgba(255,255,255,.7);
        transform: rotate(45deg) translateY(-1px);
        transition: transform 250ms ease, opacity 250ms ease;
        flex-shrink: 0;
    }
    .pc_nav-item.open > .pc_nav-link .arrow { transform: rotate(-135deg) translateY(-1px); }

    /* ─── Active Underline (scaleX animation) ────────── */
    .pc_nav-item > .pc_nav-link::after {
        content: '';
        position: absolute;
        bottom: -10px; left: 2px; right: 2px;
        height: 1.5px;
        background: rgba(255,255,255,.6);  /* 柔和白色下划线 */
        transform: scaleX(0);
        transform-origin: left center;
        transition: transform 250ms ease;
    }
    .pc_nav-item.active > .pc_nav-link::after,
    .pc_nav-item > .pc_nav-link:hover::after { transform: scaleX(1); }

    /* ─── Dropdown (Level-2) ────────────────────────── */
    .pc_nav-dropdown {
        position: absolute;
        top: calc(var(--nav-h) + 4px);
        left: 50%;
        transform: translateX(-50%);
        background: #fff;
        border-radius: var(--radius);
        box-shadow: var(--shadow);
        padding: 12px 0;
        min-width: 200px;
        opacity: 0;
        visibility: hidden;
        pointer-events: none;
        transition: opacity 200ms ease, visibility 200ms ease, transform 200ms ease;
        transform: translateX(-50%) translateY(-6px);
    }
    .pc_nav-item.open > .pc_nav-dropdown {
        opacity: 1;
        visibility: visible;
        pointer-events: auto;
        transform: translateX(-50%) translateY(0);
    }

    /* 宽下拉（Transfer Printing 三列布局） */
    .pc_nav-dropdown.wide {
        left: 0;
        transform: translateX(0) translateY(-6px);
        min-width: 880px;
        padding: 20px 0 16px;
    }
    .pc_nav-item.open > .pc_nav-dropdown.wide {
        transform: translateX(0) translateY(0);
    }
    .pc_nav-dropdown-cols {
        display: flex;
        gap: 0;
    }
    .pc_nav-dropdown-col {
        flex: 1;
        padding: 0 20px;
        border-right: 1px solid #e5e7eb;
    }
    .pc_nav-dropdown-col:last-child { border-right: none; }

    /* Level-2 分组标题（不可点击） */
    .pc_nav-l2-group-title {
        display: block;
        font-size: 14px;
        font-weight: 700;
        color: var(--brand-link);
        padding: 6px 0 2px;
        line-height: 1.4;
    }
    .pc_nav-l2-group-title a {
        color: var(--brand-link);
        transition: var(--transition);
    }
    .pc_nav-l2-group-title a:hover { opacity: .75; }

    /* Level-2 普通项 */
    .pc_nav-l2-item {
        position: relative;   /* 为三级定位 */
    }
    .pc_nav-l2-link {
        display: block;
        font-size: 13px;
        color: #374151;       /* gray-700 */
        padding: 9px 20px;
        white-space: nowrap;
        transition: var(--transition);
    }
    .pc_nav-l2-link:hover {
        color: var(--brand-link);
        background: #f0f5ff;
    }
    /* 分组标题内的链接也加上 hover */
    .pc_nav-l2-group-title a:hover {
        color: var(--brand-link);
        background: #f0f5ff;
    }
    /* 单列下拉的二级项 */
    .pc_nav-dropdown:not(.wide) .pc_nav-l2-link { padding: 10px 20px; }
    /* 宽下拉二级项 */
    .pc_nav-dropdown.wide .pc_nav-l2-link { padding: 9px 0 9px 14px; }

    /* 子标题缩进项 */
    .pc_nav-dropdown.wide .pc_nav-l2-group-title { padding: 8px 0 3px 0; }

    /* ─── Level-3 默认展开 ─────────────────────────── */
    .pc_nav-l3-menu {
        /* 内联块：紧跟在 l2 父项下方，左缩进 2 格，默认展开 */
        display: block;
        padding-left: 20px;        /* 2格缩进 */
    }

    .pc_nav-l3-link {
        display: block;
        font-size: 13px;
        color: #374151;
        padding: 7px 0 7px 4px;
        white-space: nowrap;
        transition: var(--transition);
    }
    .pc_nav-l3-link:hover { color: var(--brand-link); background: #f0f5ff; }

    /* ─── Demo page spacer ──────────────────────────── */
    .page-body {
        margin-top: var(--nav-h);
        padding: 60px 40px;
    }

    /* ════════════════════════════════════════════════════
       MOBILE NAV  (< 1300px)
    ════════════════════════════════════════════════════ */

    /* 汉堡按钮 */
    .pc_nav-hamburger {
        display: none;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        width: 40px;
        height: 40px;
        gap: 5px;
        cursor: pointer;
        background: none;
        border: none;
        padding: 4px;
        margin-left: auto;
        flex-shrink: 0;
    }
    .pc_nav-hamburger span {
        display: block;
        width: 22px;
        height: 2px;
        background: #fff;
        border-radius: 2px;
        transition: transform 250ms ease, opacity 250ms ease;
    }
    /* 展开时 → 变成 × */
    .pc_nav-hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
    .pc_nav-hamburger.open span:nth-child(2) { opacity: 0; transform: scaleX(0); }
    .pc_nav-hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

    /* 移动端全屏遮罩 */
    .pc_mobile-overlay {
        display: none;
        position: fixed;
        top: var(--nav-h);
        left: 0;
        right: 0;
        bottom: 0;
        background: #fff;
        overflow-y: auto;
        z-index: 999;
        opacity: 0;
        transform: translateY(-12px);
        transition: opacity 250ms ease, transform 250ms ease;
        pointer-events: none;  /* 隐藏时不允许点击 */
    }
    .pc_mobile-overlay.open {
        opacity: 1;
        transform: translateY(0);
        pointer-events: auto; /* 展开时允许点击 */
    }

    /* 移动端一级项 */
    .pc_mobile-item { border-bottom: 1px solid #f0f2f5; }
    .pc_mobile-link {
        display: flex;
        align-items: center;
        justify-content: space-between;
        padding: 16px 24px;
        font-family: 'Montserrat', sans-serif;
        font-weight: 500;
        font-size: 15px;
        letter-spacing: .04em;
        color: #1f2937;
        cursor: pointer;
        user-select: none;
        transition: color 250ms ease;
    }
    .pc_mobile-link:hover { color: var(--brand-link); }
    .pc_mobile-link .arrow {
        display: inline-block;
        width: 8px; height: 8px;
        border-right: 1.5px solid #9ca3af;
        border-bottom: 1.5px solid #9ca3af;
        transform: rotate(45deg) translateY(-1px);
        transition: transform 250ms ease;
        flex-shrink: 0;
    }
    .pc_mobile-item.open > .pc_mobile-link .arrow { transform: rotate(-135deg) translateY(-1px); }

    /* 移动端二级下拉 */
    .pc_mobile-dropdown {
        max-height: 0;
        overflow: hidden;
        transition: max-height 350ms cubic-bezier(0.4, 0, 0.2, 1);
    }
    .pc_mobile-item.open > .pc_mobile-dropdown {
        max-height: 2000px;
    }
    /* 展开时内容渐显 */
    .pc_mobile-dropdown-inner {
        opacity: 0;
        transform: translateY(-6px);
        transition: opacity 200ms ease, transform 250ms cubic-bezier(0.4, 0, 0.2, 1);
    }
    .pc_mobile-item.open .pc_mobile-dropdown-inner {
        opacity: 1;
        transform: translateY(0);
    }

    .pc_mobile-l2-link {
        display: block;
        padding: 11px 24px 11px 40px;
        font-size: 14px;
        font-weight: 400;
        color: #4b5563;
        letter-spacing: .01em;
        transition: color 250ms ease, background 250ms ease;
    }
    .pc_mobile-l2-link:hover { color: var(--brand-link); background: #f0f5ff; }
    /* 分组标题 */
    .pc_mobile-l2-title {
        display: block;
        padding: 12px 24px 4px 40px;
        font-size: 12px;
        font-weight: 600;
        letter-spacing: .06em;
        color: var(--brand-link);
    }

    /* 移动端三级（始终展开，缩进更多） */
    .pc_mobile-l3-link {
        display: block;
        padding: 9px 24px 9px 60px;
        font-size: 13px;
        font-weight: 400;
        color: #6b7280;
        letter-spacing: .01em;
        transition: color 250ms ease;
    }
    .pc_mobile-l3-link:hover { color: var(--brand-link); }

    /* ════════════════════════════════════════════════════
       RESPONSIVE  < 1300px
    ════════════════════════════════════════════════════ */
    @media (max-width: 1299px) {
        .pc_nav-hamburger { display: flex; }
        .pc_nav-menu      { display: none; }
        .pc_mobile-overlay { display: block; }
    }