/* ==========================================================================
   style.css — HSYWIRE Industrial Wire Manufacturer
   Revision: 3.0 — Self-hosted fonts, Cross-browser, Responsive, SEO-ready
   ========================================================================== */

/*
   Outfit Variable Font — Self-hosted locally (no Google CDN dependency).
   fonts/outfit-variable.woff2 covers weights 100–900 in a single file.
   Works in China, works offline, zero external request.
*/
@font-face {
    font-family: 'Outfit';
    font-style: normal;
    font-weight: 100 900;
    font-display: swap;
    src: url('../fonts/outfit-variable.woff2') format('woff2 supports variations'),
        url('../fonts/outfit-variable.woff2') format('woff2');
}

/* --------------------------------------------------------------------------
   Design Tokens
   -------------------------------------------------------------------------- */
:root {
    --color-primary: #003666;
    /* Deep corporate blue — nav, links, headings */
    --color-secondary: #00509e;
    /* Hover blue */
    --color-text: #333333;
    --color-text-light: #666666;
    --color-bg: #ffffff;
    --color-surface: #f5f5f5;
    --color-border: #e0e0e0;

    /* Footer — industrial dark charcoal, NOT corporate blue */
    --color-footer-bg: var(--brand-ink);
    --color-footer-text: var(--brand-n-300);
    --color-footer-link: var(--brand-n-400);
    --color-footer-head: var(--brand-n-100);

    /* Font stack — Outfit (Google) with system sans-serif fallback */
    --font-base: "Outfit", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

/* --------------------------------------------------------------------------
   Reset & Base
   -------------------------------------------------------------------------- */
*,
*::before,
*::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    /* 固定页头高约 85px：类目页锚点跳转时标题不会被页头遮住 */
    scroll-padding-top: 100px;
}

body {
    font-family: var(--font-base);
    color: var(--color-text);
    background-color: var(--color-bg);
    line-height: 1.6;
    font-size: 16px;
    font-weight: 300;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color 0.25s ease;
}

a:hover {
    color: var(--color-secondary);
}

h1,
h2,
h3,
h4 {
    color: var(--color-primary);
    font-weight: 400;
    margin-bottom: 1rem;
    letter-spacing: -0.01em;
}

h1 {
    font-weight: 300;
}

h2 {
    font-size: 2.2rem;
    margin-bottom: 2rem;
    font-weight: 300;
}

h3 {
    font-size: 1.4rem;
    font-weight: 400;
}

/* --------------------------------------------------------------------------
   Layout Utilities
   -------------------------------------------------------------------------- */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 5%;
}

.bg-light {
    background-color: var(--color-surface);
}

/* --------------------------------------------------------------------------
   Header & Navigation
   -------------------------------------------------------------------------- */
.header {
    background-color: var(--color-bg);
    padding: 1rem 0;
    border-bottom: 1px solid var(--color-border);
    position: sticky;
    top: 0;
    z-index: 1000;
    /* Subtle shadow without box-shadow for brutalist look */
    border-bottom: 1px solid var(--color-border);
}

.header-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* --------------------------------------------------------------------------
   Logo
   -------------------------------------------------------------------------- */
.logo {
    display: flex;
    align-items: center;
    gap: 0.8rem;
    text-decoration: none !important;
    flex-shrink: 0;
}

.logo-icon {
    height: 52px;
    width: auto;
    /* Cross-browser: avoid mix-blend-mode for Safari iOS < 15 */
    /* mix-blend-mode: multiply; REMOVED — use object-fit instead */
    transition: opacity 0.2s ease;
}

.logo-text-wrapper {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: flex-start;
}

.logo-text {
    font-size: 1.2rem;
    font-weight: 500;
    color: var(--color-primary);
    letter-spacing: 0.1em;
    text-transform: uppercase;
    line-height: 1;
    margin-bottom: 2px;
}

.logo-subtext {
    font-size: 0.6rem;
    font-weight: 400;
    color: var(--color-text-light);
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

/* --------------------------------------------------------------------------
   Navigation Bar
   -------------------------------------------------------------------------- */
.nav-bar {
    flex: 1;
    /* take all remaining space after logo */
    display: flex;
    align-items: center;
    gap: 0.5rem;
    justify-content: center;
    /* center nav-menu within remaining space */
}

.nav-menu {
    display: flex;
    gap: 2rem;
    list-style: none;
    margin: 0 auto;
    /* auto side margins center the menu within nav-bar */
    flex-shrink: 0;
}

/* Extra gap before Products (2nd item) */
.nav-menu .nav-has-dropdown {
    margin-left: 1.5rem;
}

.nav-menu a {
    color: var(--color-text);
    font-weight: 400;
    font-size: 0.9rem;
    letter-spacing: 0.02em;
    padding: 0.3rem 0;
    border-bottom: 2px solid transparent;
    transition: all 0.25s ease;
}

.nav-menu a:hover,
.nav-menu a.nav-active {
    color: var(--color-primary);
}

.nav-menu a.nav-active {
    border-bottom-color: var(--color-primary);
}

/* Contact CTA Button — pushed to far right by margin-left: auto on nav-cta */
.nav-cta {
    display: inline-block;
    background-color: var(--color-primary);
    color: #fff !important;
    padding: 0.6rem 1.4rem;
    font-size: 0.85rem;
    font-weight: 400;
    letter-spacing: 0.02em;
    border-radius: 2px;
    margin-left: auto;
    /* pushes CTA + lang to far right */
    flex-shrink: 0;
    transition: background-color 0.25s ease;
    white-space: nowrap;
}

.nav-cta:hover {
    background-color: var(--color-secondary);
    color: #fff !important;
}

/* --------------------------------------------------------------------------
   Language Selector
   -------------------------------------------------------------------------- */
.lang-selector {
    position: relative;
    margin-left: 1rem;
}

/* --------------------------------------------------------------------------
   Hero Section — 3-Category Split Screen
   -------------------------------------------------------------------------- */
.hero-split {
    display: flex;
    height: calc(100vh - 70px);
    min-height: 520px;
    max-height: 950px;
    width: 100%;
}

.hero-half {
    flex: 1;
    position: relative;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-decoration: none !important;
    background-size: cover;
    background-position: center;
    overflow: hidden;
    transition: flex 0.45s cubic-bezier(0.25, 1, 0.5, 1);
}

@media (min-width: 900px) {
    .hero-split:hover .hero-half {
        flex: 0.92;
    }
    .hero-split:hover .hero-half:hover {
        flex: 1.16;
    }
}

/* High-Key Bright Studio Hero Overlay —— 遮罩背景由 brand.css 统一提供 */
.hero-half::before {
    content: "";
    position: absolute;
    inset: 0;
    transition: background 0.35s ease, opacity 0.35s ease;
    z-index: 1;
}

.hero-half-content {
    position: relative;
    z-index: 2;
    text-align: center;
    color: #fff;
    transition: transform 0.35s ease;
}

/* Hero headings — 颜色由 brand.css 的品牌层决定（深蓝压亮照片） */
.hero-half-content h1,
.hero-half-content h2 {
    font-size: clamp(1.35rem, 2.1vw, 2.1rem);
    font-weight: 500;
    margin-bottom: 0.6rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    line-height: 1.25;
}

.hero-half-content p {
    font-size: clamp(0.82rem, 1vw, 0.94rem);
    font-weight: 400;
    letter-spacing: 0.02em;
    line-height: 1.5;
    color: #ffffff;
}

.hero-half-content .btn-ghost {
    display: inline-block;
    color: #fff;
    text-transform: uppercase;
    transition: background-color 0.2s ease, color 0.2s ease, border-color 0.2s ease;
}

/* --------------------------------------------------------------------------
   Company Stats Banner
   -------------------------------------------------------------------------- */
.corporate-banner {
    background-color: var(--color-surface);
    padding: 3.5rem 0;
    border-bottom: 1px solid var(--color-border);
}

.corporate-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    text-align: center;
}

.corp-item h4 {
    font-size: 1.05rem;
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    color: var(--color-primary);
    font-weight: 400;
    letter-spacing: 0.05em;
}

.corp-item p {
    color: var(--color-text);
    text-transform: uppercase;
    font-size: 0.78rem;
    font-weight: 300;
    letter-spacing: 0.05em;
}

/* --------------------------------------------------------------------------
   Product Categories & Grid (4-column layout)
   -------------------------------------------------------------------------- */
.products-section {
    padding: 3rem 0 5rem;
    text-align: left;
}

/* Section intro text */
.products-section>.container>p {
    color: var(--color-text-light);
    font-size: 1rem;
    font-weight: 300;
    margin-bottom: 3rem;
    max-width: 700px;
}

/* Each of the 4 category blocks */
.cat-section {
    margin-bottom: 4.5rem;
}

.cat-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 2rem;
    padding-bottom: 0.75rem;
    border-bottom: 2px solid var(--color-border);
}

.cat-header h2 {
    font-size: 0.82rem;
    font-weight: 500;
    color: var(--color-text-light);
    letter-spacing: 0.14em;
    text-transform: uppercase;
    margin: 0;
}

.cat-header a.cat-view-all {
    margin-left: auto;
    font-size: 0.75rem;
    color: var(--color-text-light);
    font-weight: 300;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    border-bottom: 1px solid var(--color-border);
    padding-bottom: 1px;
    transition: color 0.2s, border-color 0.2s;
}

.cat-header a.cat-view-all:hover {
    color: var(--color-primary);
    border-color: var(--color-primary);
}

/* Individual product card */
.product-card {
    display: flex;
    flex-direction: column;
    background: #fff;
    border: 1px solid var(--color-border);
    transition: border-color 0.25s, box-shadow 0.25s;
}

.product-card:hover {
    border-color: rgba(0, 54, 102, 0.35);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
}

/* Clickable image + title link */
.product-card-link {
    display: block;
    text-decoration: none;
    flex: 1;
}

/* Product image container (4:3 ratio) */
.product-card-img {
    position: relative;
    width: 100%;
    padding-top: 75%;
    /* 4:3 aspect ratio */
    overflow: hidden;
    background: var(--color-surface);
}

.product-card-img img {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.35s ease;
}

.product-card:hover .product-card-img img {
    transform: scale(1.04);
}

/* Product title */
.product-card-title {
    padding: 0.85rem 1rem 0.6rem;
    font-size: 0.88rem;
    font-weight: 400;
    color: var(--color-primary);
    letter-spacing: 0.01em;
    line-height: 1.4;
}

/* Inquiry button at bottom of each card */
.btn-inquiry {
    display: block;
    width: 100%;
    padding: 0.65rem 1rem;
    background: var(--color-surface);
    border: none;
    border-top: 1px solid var(--color-border);
    color: var(--color-text-light);
    font-size: 0.76rem;
    font-weight: 400;
    text-align: center;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    text-decoration: none;
    cursor: pointer;
    transition: background 0.2s, color 0.2s;
    font-family: inherit;
}

.btn-inquiry:hover {
    background: var(--color-primary);
    color: #fff;
    border-top-color: var(--color-primary);
}


.products-grid {
    display: grid;
    /* Use minmax with auto-fill for full cross-browser support */
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 3rem 2rem;
    margin-top: 3rem;
    text-align: left;
}

.product-item {
    display: flex;
    flex-direction: column;
}

.product-image {
    width: 100%;
    /* aspect-ratio fallback: use padding-top trick for older browsers */
    position: relative;
    overflow: hidden;
    background: #fff;
    border: 1px solid var(--color-border);
    margin-bottom: 1rem;
    padding: 12px;
    transition: border-color 0.25s ease;
}

/* Modern browsers: use aspect-ratio */
@supports (aspect-ratio: 4/3) {
    .product-image {
        aspect-ratio: 4/3;
    }

    .product-image img {
        width: 100%;
        height: 100%;
        object-fit: contain;
    }
}

/* Fallback for Safari < 15 */
@supports not (aspect-ratio: 4/3) {
    .product-image::before {
        content: "";
        display: block;
        padding-top: 75%;
        /* 4:3 */
    }

    .product-image img {
        position: absolute;
        inset: 12px;
        width: calc(100% - 24px);
        height: calc(100% - 24px);
        object-fit: contain;
    }
}

.product-item:hover .product-image {
    border-color: rgba(0, 54, 102, 0.4);
}

.product-title {
    font-size: 1rem;
    font-weight: 400;
    color: var(--color-primary);
    letter-spacing: 0.01em;
}

.product-item:hover .product-title {
    text-decoration: underline;
    color: var(--color-secondary);
}

/* --------------------------------------------------------------------------
   Technical Parameter Table
   -------------------------------------------------------------------------- */
.tech-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 2rem;
    background: #fff;
}

.tech-table th,
.tech-table td {
    border: 1px solid var(--color-border);
    padding: 0.9rem 1rem;
    text-align: left;
    font-size: 0.93rem;
}

.tech-table th {
    background-color: var(--color-surface);
    color: var(--color-primary);
    font-weight: 400;
    width: 40%;
}

.tech-table td {
    font-weight: 300;
    color: var(--color-text-light);
}

/* --------------------------------------------------------------------------
   Layout Helpers
   -------------------------------------------------------------------------- */
.layout-split {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    margin-top: 2rem;
}

/* --------------------------------------------------------------------------
   Downloads List
   -------------------------------------------------------------------------- */
.download-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    border-bottom: 1px solid var(--color-border);
    gap: 1rem;
}

.download-item strong {
    color: var(--color-primary);
    display: block;
    margin-bottom: 0.3rem;
    font-weight: 400;
}

.download-item span {
    font-size: 0.78rem;
    color: var(--color-text-light);
    font-weight: 300;
}

.download-item a {
    font-weight: 400;
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.05em;
    background: var(--color-surface);
    padding: 0.55rem 1.1rem;
    border: 1px solid var(--color-border);
    transition: all 0.25s ease;
    white-space: nowrap;
}

.download-item a:hover {
    background: #fff;
    border-color: var(--color-primary);
}

/* --------------------------------------------------------------------------
   Contact Form
   -------------------------------------------------------------------------- */
.contact-form {
    background: var(--color-surface);
    padding: 2.5rem;
    border: 1px solid var(--color-border);
}

.form-group {
    margin-bottom: 1.4rem;
}

.form-group label {
    display: block;
    font-weight: 400;
    margin-bottom: 0.4rem;
    font-size: 0.85rem;
    color: var(--color-text-light);
    letter-spacing: 0.02em;
}

.form-control {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--color-border);
    font-family: inherit;
    font-size: 0.93rem;
    font-weight: 300;
    outline: none;
    transition: border-color 0.25s;
    border-radius: 0;
    background: #fff;
    -webkit-appearance: none;
    /* iOS select fix */
    appearance: none;
}

.form-control:focus {
    border-color: var(--color-primary);
}

.btn-primary {
    display: inline-block;
    background-color: var(--color-primary);
    color: #fff;
    padding: 0.9rem 2.5rem;
    font-weight: 400;
    text-transform: uppercase;
    font-size: 0.85rem;
    transition: background-color 0.25s;
    border: none;
    cursor: pointer;
    letter-spacing: 0.1em;
    border-radius: 0;
    font-family: inherit;
}

.btn-primary:hover {
    background-color: var(--color-secondary);
    color: #fff;
}

/* --------------------------------------------------------------------------
   Footer — 深色工业底（底色/文字色由 brand.css 的品牌令牌决定）
   -------------------------------------------------------------------------- */
.footer {
    width: 100%;
    max-width: 100%;
    display: block;
    background-color: var(--color-footer-bg);
    color: var(--color-footer-text);
    padding: 4rem 0 2rem;
}

.footer > .container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 5%;
    width: 100%;
    box-sizing: border-box;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 2rem;
    margin-bottom: 3rem;
}

.footer h2, .footer h3, .footer h4 {
    color: var(--color-footer-head);
    font-size: 0.85rem;
    font-weight: 400;
    letter-spacing: 0.08em;
    margin-bottom: 1.2rem;
    text-transform: uppercase;
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    padding-bottom: 0.5rem;
}

.footer ul {
    list-style: none;
    font-size: 0.9rem;
}

.footer ul li {
    margin-bottom: 0.7rem;
}

.footer a {
    color: var(--color-footer-link);
    font-weight: 300;
    transition: color 0.2s;
}

.footer a:hover {
    color: #fff;
}

.footer-desc {
    color: var(--color-footer-link);
    font-size: 0.88rem;
    line-height: 1.7;
    margin-top: 1rem;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.08);
    padding-top: 1.5rem;
    text-align: center;
}

.footer .logo-text-wrapper {
    align-items: flex-start;
}

.footer .logo-text {
    color: #fff;
    font-size: 1.5rem;
    font-weight: 500;
    letter-spacing: 0.04em;
    /* reduced so HSYWIRE aligns visually with ZHENGTIAN GROUP below */
}

.footer .logo-subtext {
    color: var(--color-footer-link);
    font-size: 0.68rem;
}

/* --------------------------------------------------------------------------
   Responsive — Tablet (≤ 1024px)
   -------------------------------------------------------------------------- */
@media (max-width: 1024px) {
    /* 窄屏显示汉堡、隐藏桌面导航；汉堡尺寸由 brand.css 定义 */
    .hamburger {
        display: flex;
    }

    .nav-bar {
        display: none;
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

/* --------------------------------------------------------------------------
   Responsive — Tablet Portrait (≤ 768px)
   -------------------------------------------------------------------------- */
@media (max-width: 768px) {

    /* Show hamburger, hide desktop nav */
    .hamburger {
        display: flex;
    }

    .nav-bar {
        display: none;
    }

    /* whole right-side nav hidden */

    .hero-split {
        flex-direction: column;
        height: auto;
        max-height: none;
        min-height: 0;
    }

    .hero-half {
        min-height: 50vh;
        padding: 3rem 1.5rem;
    }

    .hero-half-content h2 {
        font-size: clamp(1.6rem, 6vw, 2.2rem);
    }

    .corporate-grid {
        grid-template-columns: 1fr 1fr;
    }

    .layout-split {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: 2rem;
    }

    .download-item {
        flex-direction: column;
        align-items: flex-start;
    }
}

/* --------------------------------------------------------------------------
   Responsive — Mobile (≤ 480px)
   -------------------------------------------------------------------------- */
@media (max-width: 480px) {
    h2 {
        font-size: 1.6rem;
    }

    .hero-half {
        min-height: 45vh;
        padding: 2rem 1rem;
    }

    .hero-half-content .btn-ghost {
        padding: 0.6rem 1.4rem;
        font-size: 0.72rem;
    }

    .corporate-grid {
        grid-template-columns: 1fr;
    }

    .products-grid {
        grid-template-columns: 1fr 1fr;
        gap: 1.5rem 1rem;
    }

    .footer-grid {
        grid-template-columns: 1fr;
    }

    .contact-form {
        padding: 1.5rem;
    }

    .container {
        padding: 0 4%;
    }
}

/* Cleaned duplicate dropdown CSS */

/* --------------------------------------------------------------------------
   Dynamic Spec Filter & Inquiry Styling (Preserving Exact Brand Visuals)
   -------------------------------------------------------------------------- */
.spec-filter-card {
    background: #ffffff;
    border: 1px solid var(--color-border);
    border-top: 3px solid var(--color-primary);
    box-shadow: 0 2px 10px rgba(0,0,0,0.04);
    padding: 1.8rem;
    margin: 2.5rem 0;
    border-radius: 2px;
}

.spec-filter-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
    margin-bottom: 1.5rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--color-border);
}

.spec-filter-header h3 {
    color: var(--color-primary);
    font-size: 1.35rem;
    font-weight: 400;
    margin: 0;
}

.spec-filter-controls {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    align-items: center;
    margin-bottom: 1.5rem;
}

.spec-filter-controls input[type="text"],
.spec-filter-controls select {
    font-family: var(--font-base);
    padding: 0.5rem 0.8rem;
    border: 1px solid var(--color-border);
    font-size: 0.88rem;
    color: var(--color-text);
    background: #fff;
    outline: none;
    transition: border-color 0.2s;
    border-radius: 2px;
}

.spec-filter-controls input[type="text"]:focus,
.spec-filter-controls select:focus {
    border-color: var(--color-primary);
}

.spec-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.88rem;
    text-align: left;
}

.spec-table th {
    background: var(--color-surface);
    color: var(--color-primary);
    font-weight: 500;
    padding: 0.75rem 0.9rem;
    border-bottom: 2px solid var(--color-border);
    letter-spacing: 0.02em;
}

.spec-table td {
    padding: 0.75rem 0.9rem;
    border-bottom: 1px solid var(--color-surface);
    color: var(--color-text);
    vertical-align: middle;
}

.spec-table tr:hover td {
    background: #fbfbfb;
}

.badge-gauge {
    display: inline-block;
    background: var(--color-surface);
    color: var(--color-primary);
    font-weight: 600;
    padding: 0.2rem 0.5rem;
    border-radius: 2px;
    font-size: 0.82rem;
    border: 1px solid var(--color-border);
}

.btn-spec-inquire {
    display: inline-block;
    background: transparent;
    color: var(--color-primary);
    border: 1px solid var(--color-primary);
    padding: 0.35rem 0.8rem;
    font-size: 0.8rem;
    font-weight: 400;
    text-decoration: none;
    border-radius: 2px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.btn-spec-inquire:hover {
    background: var(--color-primary);
    color: #ffffff;
}

/* Category Quick Banner */
.cat-detail-hero {
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    padding: 3rem 0 2.5rem;
}

.cat-detail-hero h1 {
    font-size: 2.2rem;
    font-weight: 300;
    color: var(--color-primary);
    margin-bottom: 0.5rem;
}

.cat-detail-hero p {
    color: var(--color-text-light);
    font-size: 0.95rem;
    max-width: 720px;
    line-height: 1.6;
}

.cat-nav-tabs {
    display: flex;
    gap: 1.5rem;
    margin-top: 1.8rem;
    flex-wrap: wrap;
}

.cat-nav-tabs a {
    font-size: 0.82rem;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    padding-bottom: 4px;
    color: var(--color-text-light);
    border-bottom: 2px solid transparent;
    transition: all 0.2s;
}

.cat-nav-tabs a:hover,
.cat-nav-tabs a.active {
    color: var(--color-primary);
    border-bottom-color: var(--color-primary);
    font-weight: 500;
}


/* --------------------------------------------------------------------------
   Accessibility & SEO Utilities (Visually Hidden elements)
   -------------------------------------------------------------------------- */
.visually-hidden,
.sr-only {
    position: absolute !important;
    width: 1px !important;
    height: 1px !important;
    padding: 0 !important;
    margin: -1px !important;
    overflow: hidden !important;
    clip: rect(0, 0, 0, 0) !important;
    white-space: nowrap !important;
    border: 0 !important;
}



/* --------------------------------------------------------------------------
   桌面导航与 Products 下拉
   层叠关系（同属 .header 层叠上下文，只比较相对顺序）：
     .header 1000 < .nav-bar 1001 < .nav-menu 1002 < 下拉面板 1003 < 顶层导航链接 1004
   页面内容最高 z-index 为 2，灯箱为 9999 —— 组内数值远高于前者、远低于后者。
   （原先是 2000/2100/2200/3000/3500 的散值，这里归一化但不改变相对顺序）
   -------------------------------------------------------------------------- */
.nav-bar {
    position: relative;
    z-index: 1001;
}

.nav-menu {
    position: relative;
    z-index: 1002;
    display: flex;
    align-items: center;
}

.nav-menu > li {
    position: relative;
}

/* 面板上沿与导航条有 12px 重叠区，顶层链接需保持在面板之上 */
.nav-menu > li > a,
.nav-cta {
    position: relative;
    z-index: 1004;
    cursor: pointer;
}

/* Products 下拉容器（面板定位相对 .header，见 style-extra.css） */
.nav-has-dropdown {
    position: relative;
    padding-bottom: 8px;
    margin-bottom: -8px;
}

/* 3-Column Dropdown Container */
.nav-dropdown,
.nav-dropdown.nav-dropdown-horizontal {
    display: flex;
    flex-direction: column;
    visibility: hidden;
    opacity: 0;
    pointer-events: none;
    position: absolute;
    top: 100%;
    left: -80px;
    transform: translateY(-4px);
    background: #ffffff;
    border: 1px solid var(--color-border);
    box-shadow: 0 16px 40px rgba(0, 30, 60, 0.14);
    border-radius: 6px;
    z-index: 1003;
    list-style: none;
    margin: 0;
    padding: 22px 28px;
    width: 820px;
    max-width: calc(100vw - 32px);
    box-sizing: border-box;
    transition: opacity 0.15s ease, visibility 0.15s ease, transform 0.15s ease;
}

/* Show dropdown ONLY when hovering .nav-has-dropdown */
.nav-has-dropdown:hover .nav-dropdown,
.nav-has-dropdown:hover .nav-dropdown.nav-dropdown-horizontal {
    visibility: visible;
    opacity: 1;
    pointer-events: auto;
    transform: translateY(0);
    transition: opacity 0.15s ease 0s, visibility 0s linear 0s, transform 0.15s ease 0s;
}

/* 下拉面板内部布局（列数由 style-extra.css 覆盖为 4 列） */
.dropdown-columns-row {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 28px;
    width: 100%;
}

.dropdown-col {
    min-width: 0;
    border-right: 1px solid var(--brand-n-100);
    padding-right: 20px;
    box-sizing: border-box;
}

.dropdown-col:last-child {
    border-right: none;
    padding-right: 0;
}

.dropdown-col .dropdown-header {
    background: transparent;
    padding: 0 0 8px 0;
    margin: 0 0 12px 0;
    border-bottom: 2px solid var(--color-primary);
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    line-height: 1.35;
    white-space: normal;
    min-height: 2.6em;
}

.dropdown-col .dropdown-header a {
    color: var(--color-primary);
    text-decoration: none;
    display: block;
    font-weight: 600;
}

.dropdown-col .dropdown-header a:hover {
    color: var(--color-secondary);
}

.dropdown-col ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.dropdown-col ul li {
    list-style: none;
    padding: 0;
    margin: 0 0 4px 0;
}

.dropdown-col ul li a {
    display: block;
    padding: 4px 0;
    font-size: 0.84rem;
    color: var(--color-text);
    text-decoration: none;
    line-height: 1.4;
    transition: color 0.15s ease, transform 0.15s ease;
}

.dropdown-col ul li a:hover {
    color: var(--color-primary);
    transform: translateX(3px);
}

/* --------------------------------------------------------------------------
   Product Catalog System (Matching Homepage Minimalist Industrial Aesthetic)
   -------------------------------------------------------------------------- */
.cat-section {
    padding: 3.5rem 0 2rem;
    border-bottom: 1px solid var(--color-border);
}

.cat-section:last-of-type {
    border-bottom: none;
}

.cat-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-end;
    margin-bottom: 2rem;
    border-bottom: 2px solid var(--color-primary);
    padding-bottom: 0.8rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.cat-header .cat-meta {
    font-size: 0.72rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--brand-n-500);
    font-weight: 600;
    display: block;
    margin-bottom: 0.3rem;
}

.cat-header h2 {
    font-size: 1.7rem;
    font-weight: 400;
    color: var(--color-primary);
    margin: 0;
    letter-spacing: -0.01em;
}

.cat-view-all {
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--color-primary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    text-decoration: none;
    transition: color 0.15s ease;
}

.cat-view-all:hover {
    color: var(--color-secondary);
}

.product-card {
    background: #ffffff;
    border: 1px solid var(--color-border);
    border-radius: 4px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    transition: border-color 0.2s ease, box-shadow 0.2s ease, transform 0.2s ease;
}

.product-card-link {
    text-decoration: none;
    color: inherit;
    display: block;
}

.product-card-img {
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.product-card-img img {
    max-height: 100%;
    max-width: 100%;
    object-fit: contain;
    transition: transform 0.3s ease;
}

.product-card:hover .product-card-img img {
    transform: scale(1.04);
}

.product-card-title {
    font-size: 0.96rem;
    font-weight: 500;
    color: var(--color-primary);
    padding: 14px 14px 4px 14px;
    line-height: 1.35;
}

.product-card-spec {
    font-size: 0.8rem;
    color: var(--brand-n-500);
    padding: 0 14px 12px 14px;
    line-height: 1.45;
}

.product-card-cta {
    margin: auto 14px 14px 14px;
    display: block;
    padding: 7px 12px;
    border: 1px solid var(--color-border);
    border-radius: 2px;
    font-size: 0.78rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.04em;
    color: var(--color-primary);
    text-align: center;
    text-decoration: none;
    transition: all 0.2s ease;
    background: #ffffff;
}

.product-card-cta:hover {
    background: var(--color-primary);
    color: #ffffff;
    border-color: var(--color-primary);
}

.product-card {
    transition: border-color 0.2s ease;
}