/* ========================================
   OmniScan X4 - Clean & Optimized Styles
   ======================================== */

/* CSS Variables */
:root {
    --color-primary: #005CB9;
    --color-primary-dark: #004499;
    --color-secondary: #F3F6F8;
    --color-text: #191919;
    --color-text-light: #666666;
    --color-white: #FFFFFF;
    --color-black: #000000;
    --color-border: #DCDDDE;
    --color-border-light: #CCCCCC;
    --color-background: #F8F9FA;
    
    --font-family: 'Noto Sans', sans-serif;
    --font-size-xs: 10px;
    --font-size-sm: 12px;
    --font-size-base: 14px;
    --font-size-md: 16px;
    --font-size-lg: 18px;
    --font-size-xl: 20px;
    --font-size-2xl: 24px;
    --font-size-3xl: 28px;
    --font-size-4xl: 32px;
    --font-size-5xl: 38px;
    
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 12px;
    --spacing-lg: 16px;
    --spacing-xl: 20px;
    --spacing-2xl: 24px;
    --spacing-3xl: 32px;
    --spacing-4xl: 40px;
    --spacing-5xl: 50px;
    --spacing-6xl: 80px;
    
    --border-radius: 8px;
    --border-radius-sm: 4px;
    --border-radius-lg: 12px;
    --border-radius-full: 50%;
    
    --shadow-sm: 0px 1px 4px 0px rgba(25, 33, 61, 0.08);
    --shadow-md: 0px 4px 12px 0px rgba(25, 33, 61, 0.15);
    
    --transition: all 0.3s ease;
    --transition-fast: all 0.2s ease;
}

/* Reset and Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-white);
    font-size: var(--font-size-md);
    padding-top: 65px; /* 预留固定头部高度 */
}

/* Container */
.container {
    max-width: 1440px;
    margin: 0 auto;
    padding: 0 var(--spacing-6xl);
}

/* ========================================
   HEADER & NAVIGATION
   ======================================== */

/* Notification Bar */
.notification-bar {
    background-color: var(--color-black);
    color: var(--color-white);
    padding: 13px 0;
    position: relative;
}

.notification-bar .container {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xl);
}

.notification-bar p {
    font-size: var(--font-size-md);
    font-weight: 400;
}

.read-more {
    color: var(--color-white);
    text-decoration: underline;
    font-weight: 700;
    font-size: var(--font-size-md);
    transition: var(--transition-fast);
}

.read-more:hover {
    opacity: 0.8;
}

.close-btn {
    position: absolute;
    right: 0;
    top: 0;
    background: none;
    border: none;
    color: var(--color-white);
    font-size: var(--font-size-2xl);
    width: 42px;
    height: 50px;
    cursor: pointer;
    transition: var(--transition-fast);
}

.close-btn:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

/* Header */
.header {
    background-color: var(--color-primary);
    height: 65px;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1100;
}

/* Sticky toolbar above sub-nav */
.sub-nav-toolbar {
    position: sticky;
    top: 65px; /* just below fixed header */
    z-index: 1050; /* above sub-nav (1000), below header (1100) */
    background: #000;
    color: #fff;
    padding: 10px 0;
    display: none; /* 默认隐藏，滚到子导航位置时才显示 */
}

.sub-nav-toolbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.toolbar-title {
    font-weight: 700;
}

.toolbar-actions { display: flex; gap: 16px; }

.toolbar-btn {
    display: inline-block;
    padding: 8px 14px;
    border-radius: 8px;
    font-size: 14px;
    text-decoration: none;
}

.toolbar-btn--ghost {
    color: #fff;
    border: 1px solid #fff;
}

.toolbar-btn--primary {
    background: #1666c6;
    color: #fff;
}

/* Mobile styles for sub-nav-toolbar */
@media (max-width: 768px) {
    .sub-nav-toolbar {
        background: #000;
        padding: 9px 0;
        z-index: 1050 !important;
        position: sticky !important;
        top: 65px !important;
    }
    
    .sub-nav-toolbar .container {
        padding: 0 var(--spacing-xl);
        gap: var(--spacing-lg);
    }
    
    .toolbar-title {
        font-size: var(--font-size-sm);
        font-weight: 400;
        line-height: 1.3;
        flex: 1;
    }
    
    .toolbar-actions {
        gap: 0;
    }
    
    /* Hide ghost buttons on mobile */
    .toolbar-btn--ghost {
        display: none;
    }
    
    /* Keep only primary button */
    .toolbar-btn--primary {
        padding: 10px 20px;
        font-size: var(--font-size-sm);
        font-weight: 500;
        white-space: nowrap;
    }
}

.nav {
    max-width: 1440px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
    padding: 0 var(--spacing-6xl);
}

.nav-brand {
    height: 65px;
}

.nav-brand img {
    height: 65px;
}

/* Center Logo */
.nav-center-logo {
    display: none;
    width: 200px;
    height: 40px;
    background-image: 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    background-size: contain;
    background-repeat: no-repeat;
    background-position: center;
}

.nav-menu {
    display: flex;
    gap: 0;
    align-items: center;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.nav-link {
    color: var(--color-white);
    text-decoration: none;
    font-size: var(--font-size-base);
    font-weight: 400;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.nav-link:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.nav-arrow {
    opacity: 1;
    transition: var(--transition);
    margin-left: var(--spacing-xs);
    display: inline-block;
    vertical-align: middle;
}

.nav-item:hover .nav-arrow {
    opacity: 0.8;
}

.nav-arrow svg {
    display: block;
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-xl);
}

/* Mobile Menu Toggle Button */
.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
    flex-direction: column;
    gap: 4px;
}

.hamburger-line {
    width: 20px;
    height: 2px;
    background-color: var(--color-white);
    transition: var(--transition);
}

.mobile-menu-toggle.active .hamburger-line:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.mobile-menu-toggle.active .hamburger-line:nth-child(2) {
    opacity: 0;
}

.mobile-menu-toggle.active .hamburger-line:nth-child(3) {
    transform: rotate(-45deg) translate(7px, -6px);
}

/* Mobile Menu */
.mobile-menu {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: var(--color-primary);
    z-index: 1200;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    display: none;
}

.mobile-menu.active {
    transform: translateX(0);
}

.mobile-menu-content {
    padding: var(--spacing-2xl);
    height: 100%;
    display: flex;
    flex-direction: column;
}

.mobile-menu-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-4xl);
    padding-bottom: var(--spacing-xl);
    border-bottom: 1px solid rgba(255, 255, 255, 0.2);
}

.wabtec-brand-mobile {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
}

.wabtec-brand-mobile .wabtec-text {
    color: var(--color-white);
    font-size: var(--font-size-lg);
    font-weight: 700;
    line-height: 1;
}

.wabtec-brand-mobile .wabtec-corp {
    color: var(--color-white);
    font-size: var(--font-size-xs);
    font-weight: 400;
    letter-spacing: 0.5px;
    margin-top: 2px;
}

.mobile-menu-close {
    background: none;
    border: none;
    color: var(--color-white);
    cursor: pointer;
    padding: var(--spacing-sm);
}

.mobile-menu-links {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.mobile-nav-link {
    color: var(--color-white);
    text-decoration: none;
    font-size: var(--font-size-lg);
    font-weight: 400;
    padding: var(--spacing-md) 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    transition: var(--transition);
}

.mobile-nav-link:hover {
    color: rgba(255, 255, 255, 0.8);
}

.mobile-menu-actions {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
    margin-top: var(--spacing-2xl);
    padding-top: var(--spacing-xl);
    border-top: 1px solid rgba(255, 255, 255, 0.2);
}

.mobile-search-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    background: none;
    border: 1px solid var(--color-white);
    color: var(--color-white);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: var(--transition);
}

.mobile-search-btn:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.mobile-language-selector {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--color-white);
    font-size: var(--font-size-base);
}

/* ========================================
   SEARCH MODAL & BAR
   ======================================== */

/* Desktop Search Modal */
.search-modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 2000;
    display: none;
    align-items: center;
    justify-content: center;
}

.search-modal.active {
    display: flex;
}

.search-modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
}

.search-modal-content {
    position: relative;
    background-color: var(--color-white);
    border-radius: 12px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
    width: 90%;
    max-width: 600px;
    padding: 0;
    animation: searchModalSlideIn 0.3s ease;
}

@keyframes searchModalSlideIn {
    from {
        opacity: 0;
        transform: scale(0.9) translateY(-20px);
    }
    to {
        opacity: 1;
        transform: scale(1) translateY(0);
    }
}

.search-modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 24px 24px 0;
    border-bottom: 1px solid #E5E7EB;
    margin-bottom: 24px;
}

.search-modal-header h3 {
    font-size: var(--font-size-xl);
    font-weight: 600;
    color: var(--color-text);
    margin: 0;
}

.search-modal-close {
    background: none;
    border: none;
    color: var(--color-text-light);
    cursor: pointer;
    padding: 8px;
    border-radius: 6px;
    transition: var(--transition-fast);
}

.search-modal-close:hover {
    background-color: #F3F4F6;
    color: var(--color-text);
}

.search-modal-body {
    padding: 0 24px 24px;
}

.search-input-group {
    display: flex;
    gap: 12px;
    margin-bottom: 12px;
}

.search-input-wrapper {
    flex: 1;
    position: relative;
    display: flex;
    align-items: center;
}

.search-icon {
    position: absolute;
    left: 16px;
    color: var(--color-text-light);
    z-index: 1;
}

.search-input {
    width: 100%;
    padding: 16px 16px 16px 48px;
    border: 1px solid #D1D5DB;
    border-radius: 8px;
    font-size: var(--font-size-md);
    color: var(--color-text);
    background-color: var(--color-white);
    transition: var(--transition-fast);
}

.search-input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(0, 92, 185, 0.1);
}

.search-submit-btn {
    background-color: var(--color-primary);
    color: var(--color-white);
    border: none;
    padding: 16px 24px;
    border-radius: 8px;
    font-size: var(--font-size-md);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-fast);
    white-space: nowrap;
}

.search-submit-btn:hover {
    background-color: var(--color-primary-dark);
}

.search-hint {
    color: var(--color-text-light);
    font-size: var(--font-size-sm);
    margin: 0;
    text-align: center;
}

/* Mobile Search Bar */
.mobile-search-bar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 2000;
    background-color: var(--color-white);
    border-bottom: 1px solid #E5E7EB;
    padding: 16px;
    display: none;
    animation: mobileSearchSlideDown 0.3s ease;
}

.mobile-search-bar.active {
    display: block;
}

@keyframes mobileSearchSlideDown {
    from {
        opacity: 0;
        transform: translateY(-100%);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.mobile-search-content {
    display: flex;
    align-items: center;
    gap: 12px;
    max-width: 100%;
}

.mobile-search-input-wrapper {
    flex: 1;
    position: relative;
    display: flex;
    align-items: center;
}

.mobile-search-icon {
    position: absolute;
    left: 12px;
    color: var(--color-text-light);
    z-index: 1;
}

.mobile-search-input {
    width: 100%;
    padding: 12px 12px 12px 40px;
    border: 1px solid #D1D5DB;
    border-radius: 6px;
    font-size: var(--font-size-base);
    color: var(--color-text);
    background-color: var(--color-white);
    transition: var(--transition-fast);
}

.mobile-search-input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 2px rgba(0, 92, 185, 0.1);
}

.mobile-search-submit-btn {
    background-color: var(--color-primary);
    color: var(--color-white);
    border: none;
    padding: 12px 20px;
    border-radius: 6px;
    font-size: var(--font-size-base);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-fast);
    white-space: nowrap;
}

.mobile-search-submit-btn:hover {
    background-color: var(--color-primary-dark);
}

.shop-btn {
    background-color: var(--color-primary);
    color: var(--color-white);
    border: none;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--border-radius);
    font-size: var(--font-size-base);
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    transition: var(--transition);
}

.shop-btn:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.shop-btn svg {
    display: block;
    flex-shrink: 0;
}

.language-selector {
    color: var(--color-white);
    font-size: var(--font-size-base);
    font-weight: 400;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.language-selector:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.language-selector svg {
    display: block;
    flex-shrink: 0;
}

.search-btn {
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.search-btn:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.search-btn img {
    display: block;
}

.wabtec-brand {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    color: var(--color-white);
    font-size: var(--font-size-sm);
    font-weight: 400;
}

.wabtec-text {
    font-size: var(--font-size-md);
    font-weight: 700;
    line-height: 1;
}

.wabtec-corp {
    font-size: var(--font-size-xs);
    font-weight: 400;
    line-height: 1;
    margin-top: 2px;
}

/* ========================================
   BREADCRUMB
   ======================================== */

.breadcrumb {
    padding: var(--spacing-3xl) 0;
    border-bottom: 1px solid var(--color-border);
}

.breadcrumb .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.breadcrumb-nav {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.breadcrumb-link {
    color: var(--color-text-light);
    text-decoration: none;
    font-size: var(--font-size-sm);
    font-weight: 400;
    transition: var(--transition-fast);
}

.breadcrumb-link:hover {
    color: var(--color-primary);
}

.breadcrumb-separator {
    color: var(--color-text-light);
    font-size: var(--font-size-sm);
}

.breadcrumb-current {
    color: var(--color-text);
    font-size: var(--font-size-sm);
    font-weight: 400;
}

.share-links {
    display: flex;
    gap: var(--spacing-md);
}

.share-button,
.linkedin-button {
    width: 28px;
    height: 28px;
    padding: 5px;
    border: none;
    border-radius: var(--border-radius-full);
    background-color: var(--color-primary);
    background-repeat: no-repeat;
    background-size: 18px 18px;
    background-position: center;
    cursor: pointer;
    outline: none;
    transition: var(--transition);
}

.share-button {
    background-image: url("data:image/svg+xml,%3csvg%20xmlns='http://www.w3.org/2000/svg'%20width='18'%20height='18'%20viewBox='0%200%2018%2018'%20fill='none'%3e%3cpath%20d='M11.625%2015H4.125V5.25C4.125%204.8375%203.7875%204.5%203.375%204.5C2.9625%204.5%202.625%204.8375%202.625%205.25V15C2.625%2015.825%203.3%2016.5%204.125%2016.5H11.625C12.0375%2016.5%2012.375%2016.1625%2012.375%2015.75C12.375%2015.3375%2012.0375%2015%2011.625%2015ZM15.375%2012V3C15.375%202.175%2014.7%201.5%2013.875%201.5H7.125C6.3%201.5%205.625%202.175%205.625%203V12C5.625%2012.825%206.3%2013.5%207.125%2013.5H13.875C14.7%2013.5%2015.375%2012.825%2015.375%2012ZM13.875%2012H7.125V3H13.875V12Z'%20fill='white'/%3e%3c/svg%3e");
}

.linkedin-button {
    background-image: url("data:image/svg+xml,%3csvg%20width='18'%20height='19'%20viewBox='0%200%2018%2019'%20fill='none'%20xmlns='http://www.w3.org/2000/svg'%3e%3cpath%20d='M15.3896%201.6543H2.60742C1.99512%201.6543%201.5%202.1377%201.5%202.73535V15.5703C1.5%2016.168%201.99512%2016.6543%202.60742%2016.6543H15.3896C16.002%2016.6543%2016.5%2016.168%2016.5%2015.5732V2.73535C16.5%202.1377%2016.002%201.6543%2015.3896%201.6543ZM5.9502%2014.4365H3.72363V7.27637H5.9502V14.4365ZM4.83691%206.30078C4.12207%206.30078%203.54492%205.72363%203.54492%205.01172C3.54492%204.2998%204.12207%203.72266%204.83691%203.72266C5.54883%203.72266%206.12598%204.2998%206.12598%205.01172C6.12598%205.7207%205.54883%206.30078%204.83691%206.30078ZM14.2822%2014.4365H12.0586V10.9561C12.0586%2010.127%2012.0439%209.05762%2010.9014%209.05762C9.74414%209.05762%209.56836%209.96289%209.56836%2010.8975V14.4365H7.34766V7.27637H9.48047V8.25488H9.50977C9.80566%207.69238%2010.5322%207.09766%2011.6133%207.09766C13.8662%207.09766%2014.2822%208.58008%2014.2822%2010.5078V14.4365Z'%20fill='white'/%3e%3c/svg%3e");
}

.share-button:hover,
.linkedin-button:hover {
    opacity: 0.8;
}

/* ========================================
   PRODUCT SHOWCASE
   ======================================== */

.product-showcase {
    padding: var(--spacing-6xl) 0;
}

.product-showcase .container {
    display: grid;
    grid-template-columns: 520px 1fr;
    gap: var(--spacing-6xl);
    align-items: start;
}

.product-gallery {
    position: relative;
}

.gallery-container {
    position: relative;
    overflow: hidden;
    border-radius: var(--border-radius);
}

.gallery-slide {
    display: none;
}

.gallery-slide.active {
    display: block;
}

.gallery-slide img {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
}

.gallery-controls {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.gallery-btn {
    background-color: #F2F7FB;
    border: none;
    width: 24px;
    height: 24px;
    border-radius: 10px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.gallery-btn:hover {
    background-color: #E6F3FF;
}

.gallery-btn svg {
    display: block;
    flex-shrink: 0;
}

.gallery-dots {
    display: flex;
    gap: var(--spacing-sm);
}

.dot {
    width: 10px;
    height: 10px;
    border-radius: var(--border-radius-full);
    border: 1px solid var(--color-primary);
    background: transparent;
    cursor: pointer;
    transition: var(--transition);
}

.dot.active {
    background-color: var(--color-primary);
}

.product-title {
    font-size: var(--font-size-4xl);
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: var(--spacing-xl);
    color: var(--color-text);
}

.product-sku {
    font-size: var(--font-size-md);
    font-weight: 400;
    color: var(--color-text);
    margin-bottom: var(--spacing-xl);
}

.product-description {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    color: var(--color-text);
    margin-bottom: 30px;
}

.product-details h3 {
    font-size: var(--font-size-md);
    font-weight: 600;
    margin-bottom: 15px;
    color: var(--color-text);
}

.product-details ul {
    list-style: none;
    margin-left: 40px;
}

.product-details li {
    font-size: var(--font-size-md);
    font-weight: 400;
    margin-bottom: 10px;
    color: var(--color-text);
}

.product-details a {
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition-fast);
}

.product-details a:hover {
    text-decoration: underline;
}

.cta-button {
    background-color: var(--color-primary);
    color: var(--color-white);
    border: none;
    padding: var(--spacing-lg) var(--spacing-3xl);
    border-radius: var(--border-radius);
    font-size: var(--font-size-md);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    margin-top: var(--spacing-xl);
    text-decoration: none;
    display: inline-block;
}

.cta-button:hover {
    background-color: var(--color-primary-dark);
    transform: translateY(-1px);
}

/* 链接型按钮（用于 Black Box App 等区域） */
.button {
    display: inline-block;
    background-color: var(--color-primary);
    color: var(--color-white) !important; /* 确保文字为白色 */
    text-decoration: none;
    padding: 12px 22px;
    border-radius: var(--border-radius);
    font-size: var(--font-size-md);
    font-weight: 700;
    line-height: 1.2;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.button:visited { color: var(--color-white) !important; }

.button:hover {
    background-color: var(--color-primary-dark);
    transform: translateY(-1px);
}

.button-container { margin: 16px 0; }

/* ========================================
   SUB NAVIGATION
   ======================================== */

.sub-nav {
    background-color: var(--color-white);
    border-bottom: 1px solid var(--color-border);
    padding: var(--spacing-lg) 0;
    position: sticky; /* 当滚动到该位置后吸顶 */
    top: 105px; /* 避开固定头部+工具条高度（约40px） */
    z-index: 1000;
    background: var(--color-white);
}

.sub-nav-menu {
    display: flex;
    gap: 0;
}

.sub-nav-link {
    color: #545556;
    text-decoration: none;
    font-size: var(--font-size-base);
    font-weight: 400;
    padding: 18px 13px;
    border-radius: var(--border-radius);
    transition: var(--transition);
    white-space: nowrap;
}

.sub-nav-link.active {
    color: var(--color-primary);
    font-weight: 800;
}

.sub-nav-link:hover {
    background-color: #F2F7FB;
}

/* Mobile Sub Navigation Dropdown */
.mobile-sub-nav {
    display: none;
    position: relative;
}

.mobile-sub-nav-toggle {
    width: 100%;
    background-color: #F8F9FA; /* 更浅的灰色背景 */
    border: 1px solid #E9ECEF; /* 更细更淡的边框 */
    border-radius: 6px; /* 更小的圆角 */
    padding: 14px 16px; /* 增加内边距 */
    display: flex;
    align-items: center;
    justify-content: space-between;
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: var(--font-size-base);
    color: var(--color-text);
    font-weight: 400;
    box-shadow: none; /* 移除阴影 */
}

.mobile-sub-nav-toggle:hover {
    background-color: #F1F3F4; /* 悬停时稍微深一点的灰色 */
    border-color: #DEE2E6;
}

.mobile-sub-nav-toggle.active {
    border-bottom-left-radius: 0;
    border-bottom-right-radius: 0;
    background-color: #F8F9FA;
}

.mobile-sub-nav-text {
    font-weight: 400;
    color: var(--color-text);
    font-size: var(--font-size-base);
}

.mobile-sub-nav-chevron {
    transition: transform 0.2s ease;
    color: var(--color-text);
    opacity: 0.7; /* 箭头稍微透明 */
}

.mobile-sub-nav-toggle.active .mobile-sub-nav-chevron {
    transform: rotate(180deg);
}

.mobile-sub-nav-menu {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background-color: var(--color-white);
    border: 1px solid #E9ECEF; /* 与按钮相同的边框颜色 */
    border-top: none;
    border-bottom-left-radius: 6px; /* 与按钮相同的圆角 */
    border-bottom-right-radius: 6px;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1); /* 轻微阴影 */
    z-index: 1000;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.2s ease;
}

.mobile-sub-nav-menu.active {
    max-height: 300px;
}

.mobile-sub-nav-link {
    display: block;
    padding: 12px 16px; /* 与按钮相同的内边距 */
    color: var(--color-text);
    text-decoration: none;
    font-size: var(--font-size-base);
    font-weight: 400;
    border-bottom: 1px solid #F1F3F4; /* 更淡的分隔线 */
    transition: all 0.15s ease;
}

.mobile-sub-nav-link:last-child {
    border-bottom: none;
}

.mobile-sub-nav-link:hover {
    background-color: #F8F9FA; /* 悬停时使用按钮相同的背景色 */
    color: var(--color-primary);
}

.mobile-sub-nav-link.active {
    background-color: #E3F2FD; /* 更淡的蓝色背景 */
    color: var(--color-primary);
    font-weight: 500; /* 稍微加粗 */
}

/* ========================================
   CONTENT SECTIONS
   ======================================== */

.features-section,
.expert-section,
.performance-section,
.pci-section,
.tfm-section,
.twin-section,
.speed-section,
.applications-section,
.solutions-section,
.specifications-section,
.resources-section {
    padding: var(--spacing-6xl) 0;
}

.expert-section,
.pci-section,
.solutions-section {
    background-color: var(--color-secondary);
}

.feature-content,
.expert-content,
.performance-content,
.pci-content,
.tfm-main-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-6xl);
    align-items: center;
}

.tfm-text-content {
    padding-right: var(--spacing-4xl);
}

.tfm-text-content h2 {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    line-height: 1.15;
    margin-bottom: 30px;
    color: var(--color-text);
}

.tfm-text-content p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 20px;
    color: var(--color-text);
}

.tfm-note {
    font-size: var(--font-size-sm);
    color: var(--color-text-light);
    font-style: italic;
    margin-bottom: 30px;
}

.tfm-cta {
    margin-top: 30px;
}

.tfm-image-content {
    display: flex;
    justify-content: center;
    align-items: center;
}

.tfm-image-content img {
    width: 100%;
    max-width: 500px;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.twin-main-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-6xl);
    align-items: center;
}

.twin-image-content {
    display: flex;
    justify-content: center;
    align-items: center;
}

.twin-image-content img {
    width: 100%;
    max-width: 500px;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.twin-text-content {
    padding-left: var(--spacing-4xl);
}

.twin-text-content h3 {
    font-size: var(--font-size-4xl);
    font-weight: 700;
    line-height: 1.15;
    margin-bottom: 20px;
    color: var(--color-text);
}

.twin-text-content h4 {
    font-size: 26px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 30px;
    color: var(--color-text);
}

.twin-text-content p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    color: var(--color-text);
}

.performance-content {
    grid-template-columns: 1fr 608px;
}

.feature-image img,
.expert-video video,
.performance-image img,
.pci-image img {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
}

.expert-video {
    position: relative;
}

.expert-video video {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
}

.feature-text h2,
.expert-text h2,
.performance-text h2,
.speed-content h2 {
    font-size: var(--font-size-4xl);
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 30px;
    color: var(--color-text);
}

.feature-text p,
.expert-text p,
.performance-text p,
.speed-content > p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 30px;
    color: var(--color-text);
}

.feature-list {
    list-style: none;
    margin-bottom: 30px;
}

.feature-list li {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 15px;
    color: var(--color-text);
    padding-left: 40px;
    position: relative;
}

.feature-list li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--color-text);
    font-weight: bold;
}

.patent-note {
    font-size: var(--font-size-md);
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: var(--spacing-xl);
}

.pci-text h3 {
    font-size: 26px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 30px;
    color: var(--color-text);
}

.pci-text p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 30px;
    color: var(--color-text);
}

.pci-buttons {
    display: flex;
    gap: var(--spacing-xl);
    flex-wrap: wrap;
}

.twin-content h3 {
    font-size: 26px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: var(--spacing-xl);
    color: var(--color-text);
}

.twin-content h4 {
    font-size: 22px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: var(--spacing-xl);
    color: var(--color-text);
}

.twin-content p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    color: var(--color-text);
}

.speed-features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-6xl);
}

.speed-feature img {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
    margin-bottom: 30px;
}

.speed-feature h3 {
    font-size: 26px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: var(--spacing-xl);
    color: var(--color-text);
}

.speed-feature p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 15px;
    color: var(--color-text);
}

/* ========================================
   APPLICATIONS SECTION
   ======================================== */

.applications-section h2 {
    font-size: var(--font-size-5xl);
    font-weight: 200;
    line-height: 1.15;
    margin-bottom: 30px;
    color: var(--color-text);
}

.applications-section h3 {
    font-size: var(--font-size-4xl);
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 30px;
    color: var(--color-text);
}

.applications-section > p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: var(--spacing-5xl);
    color: var(--color-text);
}

.applications-content {
    display: grid;
    grid-template-columns: 1fr 600px;
    gap: var(--spacing-6xl);
    align-items: center;
    margin-bottom: var(--spacing-5xl);
}

.applications-text h2 { margin-bottom: 10px; }
.applications-text h3 { margin-bottom: 16px; }

.applications-visual img {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
}

.applications-table {
    overflow-x: auto;
    margin-bottom: 30px;
    border: 1px solid #D1D5DB; /* 容器灰色描边 */
    border-radius: var(--border-radius);
    overflow: hidden; /* 让圆角作用于内部表格 */
}

.applications-table table {
    width: 100%;
    border-collapse: collapse;
    border: none; /* 外边框由容器提供 */
    border-radius: 0;
    overflow: hidden;
}

.applications-table th,
.applications-table td {
    padding: 20px 20px; /* 收紧内边距，整体更紧凑 */
    text-align: left;
    border-right: 1px solid #E5E7EB; /* closer to old.html appearance */
    border-bottom: 1px solid #E5E7EB;
    vertical-align: top;
}

.applications-table th {
    background-color: var(--color-background);
    font-size: var(--font-size-md);
    font-weight: 600;
    color: var(--color-text);
}

.applications-table td {
    font-size: var(--font-size-md);
    font-weight: 400;
    color: var(--color-text);
    line-height: 1.5; /* 行距更紧凑 */
}

.applications-table ul {
    list-style: none;
    margin: 0 0 8px; /* 收紧列表与段落间距 */
    padding: 0;
}

.applications-table li {
    margin-bottom: 8px; /* 列表项间距更小 */
    padding-left: 24px; /* 更贴近旧页 */
    position: relative;
}

/* 收紧单元格内段落间距 */
.applications-table td p {
    margin: 0 0 8px;
    line-height: 1.5;
}

.applications-table li::before {
    content: "•";
    position: absolute;
    left: 0;
    top: 0.1em; /* align bullet vertically with first line */
    color: var(--color-text);
    font-weight: bold;
}

/* ========================================
   SOLUTIONS SECTION
   ======================================== */

.solutions-section h2 {
    font-size: var(--font-size-4xl);
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 30px;
    color: var(--color-text);
}

.solutions-section > p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: var(--spacing-5xl);
    color: var(--color-text);
}

.solutions-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-4xl);
}

.solution-item h3 {
    font-size: 22px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: var(--spacing-xl);
    color: var(--color-text);
}

.solution-item img {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
}

/* ========================================
   SPECIFICATIONS SECTION
   ======================================== */

.specifications-section h2 {
    font-size: var(--font-size-5xl);
    font-weight: 200;
    line-height: 1.15;
    margin-bottom: var(--spacing-xl);
    color: var(--color-text);
}

.specifications-section > p {
    font-size: var(--font-size-md);
    font-weight: 400;
    margin-bottom: 30px;
    color: var(--color-text);
}

.specifications-section h3 {
    font-size: var(--font-size-4xl);
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 30px;
    color: var(--color-text);
}

.specs-table {
    overflow-x: auto;
    margin-bottom: 30px;
    border: 1px solid rgb(204, 204, 204); /* 外层1px描边 */
    border-radius: var(--border-radius);
    overflow: hidden; /* 让圆角生效 */
}

.specs-table table {
    width: 100%;
    border-collapse: collapse;
    border: none; /* 外边框由容器提供，避免双重边框 */
    border-radius: 0;
    overflow: hidden;
}

.specs-table td {
    padding: 25px 24px;
    text-align: left;
    border-right: 1px solid var(--color-border-light);
    border-bottom: 1px solid var(--color-border-light);
    font-size: var(--font-size-md);
    font-weight: 400;
    color: var(--color-text);
}

.specs-table td:first-child {
    font-weight: 600;
    background-color: var(--color-background);
    width: 30%;
}

/* ========================================
   HTHA SOLUTIONS SECTION
   ======================================== */

.htha-section {
    padding: var(--spacing-6xl) 0;
}

.htha-section h2 {
    font-size: var(--font-size-4xl);
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 30px;
    color: var(--color-text);
}

.htha-section h3 {
    font-size: 26px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 20px;
    color: var(--color-text);
}

.htha-section h4 {
    font-size: 22px;
    font-weight: 400;
    line-height: 1.3;
    margin-bottom: 20px;
    color: var(--color-text);
}

.htha-section p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 20px;
    color: var(--color-text);
}

.htha-section ul {
    list-style: none;
    margin-bottom: 20px;
}

.htha-section li {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 10px;
    color: var(--color-text);
    padding-left: 20px;
    position: relative;
}

.htha-section li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--color-text);
    font-weight: bold;
}

/* ========================================
   WELD SOLUTIONS SECTION
   ======================================== */

.weld-solutions-section {
    padding: var(--spacing-6xl) 0;
}

.weld-solutions-section h2 {
    font-size: var(--font-size-4xl);
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 30px;
    color: var(--color-text);
}

.weld-solutions-section h3 {
    font-size: 26px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 20px;
    color: var(--color-text);
}

.weld-solutions-section h4 {
    font-size: 22px;
    font-weight: 400;
    line-height: 1.3;
    margin-bottom: 20px;
    color: var(--color-text);
}

.weld-content {
    display: grid;
    grid-template-columns: 1fr 658px;
    gap: var(--spacing-6xl);
    align-items: start;
    margin-bottom: 40px;
}

.weld-text p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 20px;
    color: var(--color-text);
}

.weld-text ul {
    list-style: none;
    margin-bottom: 20px;
}

.weld-text li {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 10px;
    color: var(--color-text);
    padding-left: 20px;
    position: relative;
}

.weld-text li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--color-text);
    font-weight: bold;
}

.weld-image img {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
}

.weld-applications {
    display: grid;
    grid-template-columns: 400px 1fr;
    gap: var(--spacing-6xl);
    align-items: start;
    margin-bottom: 40px;
    background-color: var(--color-background-light);
    padding: var(--spacing-4xl);
    border-radius: var(--border-radius);
}

.weld-app-image img {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
}

.weld-app-text p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 20px;
    color: var(--color-text);
}

.weld-app-text ul {
    list-style: none;
    margin-bottom: 20px;
}

.weld-app-text li {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 10px;
    color: var(--color-text);
    padding-left: 20px;
    position: relative;
}

.weld-app-text li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--color-text);
    font-weight: bold;
}

.weld-techniques {
    margin-bottom: 40px;
}

.weld-techniques h3 {
    font-size: 26px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 20px;
    color: var(--color-text);
}

.weld-techniques p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 30px;
    color: var(--color-text);
}

.techniques-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-4xl);
}

.technique-item {
    text-align: center;
}

.technique-item img {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
    margin-bottom: 15px;
}

.technique-item h4 {
    font-size: 18px;
    font-weight: 400;
    line-height: 1.3;
    color: var(--color-text);
}

.tofd-experience {
    display: grid;
    grid-template-columns: 1fr 658px;
    gap: var(--spacing-6xl);
    align-items: start;
    margin-bottom: 40px;
    background-color: var(--color-background-light);
    padding: var(--spacing-4xl);
    border-radius: var(--border-radius);
}

.tofd-text h3 {
    font-size: 26px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 20px;
    color: var(--color-text);
}

.tofd-text p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    color: var(--color-text);
}

.tofd-image img {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
}

.data-management {
    display: grid;
    grid-template-columns: 483px 1fr;
    gap: var(--spacing-6xl);
    align-items: start;
    margin-bottom: 40px;
}

.data-image img {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
}

.data-text h3 {
    font-size: 26px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 20px;
    color: var(--color-text);
}

.data-text ul {
    list-style: none;
    margin-bottom: 20px;
}

.data-text li {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 10px;
    color: var(--color-text);
    padding-left: 20px;
    position: relative;
}

.data-text li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--color-text);
    font-weight: bold;
}

.demanding-environments {
    display: grid;
    grid-template-columns: 1fr 658px;
    gap: var(--spacing-6xl);
    align-items: start;
    background-color: var(--color-background-light);
    padding: var(--spacing-4xl);
    border-radius: var(--border-radius);
}

.env-text h3 {
    font-size: 26px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 20px;
    color: var(--color-text);
}

.env-text ul {
    list-style: none;
    margin-bottom: 20px;
}

.env-text li {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 10px;
    color: var(--color-text);
    padding-left: 20px;
    position: relative;
}

.env-text li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--color-text);
    font-weight: bold;
}

.env-image img {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
}

/* ========================================
   CORROSION SOLUTIONS SECTION
   ======================================== */

.corrosion-solutions-section {
    padding: var(--spacing-6xl) 0;
}

.corrosion-solutions-section h2 {
    font-size: var(--font-size-4xl);
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 30px;
    color: var(--color-text);
}

.corrosion-solutions-section h3 {
    font-size: 26px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 20px;
    color: var(--color-text);
}

.corrosion-solutions-section p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 20px;
    color: var(--color-text);
}

.corrosion-main-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-6xl);
    align-items: start;
    margin: 40px 0;
    padding: 0;
}

.corrosion-text-content {
    padding-right: var(--spacing-4xl);
}

.corrosion-features-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.corrosion-features-list li {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 16px;
    color: var(--color-text);
    padding-left: 24px;
    position: relative;
}

.corrosion-features-list li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--color-primary);
    font-weight: bold;
    font-size: 18px;
}

.corrosion-features-list a {
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition-fast);
}

.corrosion-features-list a:hover {
    text-decoration: underline;
}

.corrosion-image-content {
    display: flex;
    justify-content: center;
    align-items: center;
}

.corrosion-image-content img {
    width: 100%;
    max-width: 600px;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

.corrosion-additional-content {
    margin-top: 60px;
}

.corrosion-additional-content h3 {
    font-size: 26px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 20px;
    color: var(--color-text);
}

.corrosion-additional-content p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 40px;
    color: var(--color-text);
}

.corrosion-environment {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-6xl);
    align-items: start;
    margin-top: 40px;
    background-color: var(--color-background-light);
    padding: var(--spacing-4xl);
    border-radius: var(--border-radius);
}

.corrosion-env-text h3 {
    font-size: 26px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 20px;
    color: var(--color-text);
}

.corrosion-env-text ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.corrosion-env-text li {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 12px;
    color: var(--color-text);
    padding-left: 24px;
    position: relative;
}

.corrosion-env-text li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--color-primary);
    font-weight: bold;
    font-size: 18px;
}

.corrosion-env-image {
    display: flex;
    justify-content: center;
    align-items: center;
}

.corrosion-env-image img {
    width: 100%;
    max-width: 600px;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

/* ========================================
   ONBOARD SOFTWARE SECTION
   ======================================== */

.onboard-software-section {
    padding: var(--spacing-6xl) 0;
}

.onboard-software-section h2 {
    font-size: var(--font-size-4xl);
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 30px;
    color: var(--color-text);
}

.onboard-software-section h3 {
    font-size: 26px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 20px;
    color: var(--color-text);
}

.onboard-software-section p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 20px;
    color: var(--color-text);
}

.software-evolve {
    display: grid;
    grid-template-columns: 1fr 600px;
    gap: var(--spacing-6xl);
    align-items: start;
    margin-bottom: 40px;
}

.evolve-text h3 {
    font-size: 26px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 20px;
    color: var(--color-text);
}

.evolve-text p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 20px;
    color: var(--color-text);
}

.evolve-image img {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
}

.black-box-app {
    display: grid;
    grid-template-columns: 1fr 600px; /* 文本左侧，右侧受控宽度 */
    gap: var(--spacing-6xl);
    align-items: center;
    margin-bottom: 40px;
    background-color: var(--color-secondary); /* 淡灰背景，匹配左图 */
    padding: var(--spacing-4xl);
    border-radius: var(--border-radius);
}

.black-box-text h4 {
    font-size: 22px;
    font-weight: 400;
    line-height: 1.3;
    margin-bottom: 15px;
    color: var(--color-text);
}

.black-box-text h5 {
    font-size: 20px;
    font-weight: 400;
    line-height: 1.3;
    margin-bottom: 15px;
    color: var(--color-text);
}

.black-box-text p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 20px;
    color: var(--color-text);
}

.black-box-text ul {
    list-style: none;
    margin-bottom: 20px;
}

.black-box-text li {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 10px;
    color: var(--color-text);
    padding-left: 20px;
    position: relative;
}

.black-box-text li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--color-text);
    font-weight: bold;
}

.black-box-text a {
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition-fast);
}

.black-box-text a:hover {
    text-decoration: underline;
}

.black-box-image img {
    width: 100%;
    max-width: 600px; /* 防止图片过大 */
    height: auto;
    border-radius: var(--border-radius);
    display: block;
}

.api-fmc {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-6xl);
    align-items: start;
}

.api-text h4,
.fmc-text h4 {
    font-size: 22px;
    font-weight: 400;
    line-height: 1.3;
    margin-bottom: 15px;
    color: var(--color-text);
}

.api-text p,
.fmc-text p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 20px;
    color: var(--color-text);
}

/* ========================================
   OMNIPC SECTION
   ======================================== */

.omnipc-section {
    padding: var(--spacing-6xl) 0;
}

.omnipc-section h2 {
    font-size: var(--font-size-4xl);
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 30px;
    color: var(--color-text);
}

.omnipc-section h3 {
    font-size: 26px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 20px;
    color: var(--color-text);
}

.omnipc-intro {
    display: grid;
    grid-template-columns: 1fr 608px;
    gap: var(--spacing-6xl);
    align-items: start;
    margin-bottom: 40px;
}

.omnipc-advantages {
    margin-bottom: 40px;
    background-color: var(--color-background-light);
    padding: var(--spacing-4xl);
    border-radius: var(--border-radius);
}

.omnipc-advantages h3 {
    font-size: 26px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 20px;
    color: var(--color-text);
}

.omnipc-advantages p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 20px;
    color: var(--color-text);
}

.omnipc-advantages ul {
    list-style: none;
    margin-bottom: 20px;
}

.omnipc-advantages li {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 10px;
    color: var(--color-text);
    padding-left: 20px;
    position: relative;
}

.omnipc-advantages li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--color-text);
    font-weight: bold;
}

.video-demos {
    margin-top: 40px;
}

.video-demo {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-4xl);
    align-items: start;
    margin-bottom: 40px;
    padding: var(--spacing-4xl);
    background-color: var(--color-background-light);
    border-radius: var(--border-radius);
}

.video-container {
    width: 100%;
}

.video-container video {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
}

.video-text h3,
.video-text h4 {
    font-size: 22px;
    font-weight: 400;
    line-height: 1.3;
    margin-bottom: 15px;
    color: var(--color-text);
}

.video-text p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    color: var(--color-text);
}

.omnipc-image img {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
}

.omnipc-text h3 {
    font-size: 26px;
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: 20px;
    color: var(--color-text);
}

.omnipc-text p {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 20px;
    color: var(--color-text);
}

.omnipc-text ul {
    list-style: none;
    margin-bottom: 20px;
}

.omnipc-text li {
    font-size: var(--font-size-md);
    font-weight: 400;
    line-height: 1.6;
    margin-bottom: 10px;
    color: var(--color-text);
    padding-left: 20px;
    position: relative;
}

.omnipc-text li::before {
    content: "•";
    position: absolute;
    left: 0;
    color: var(--color-text);
    font-weight: bold;
}

.software-table {
    overflow-x: auto;
    margin: 30px 0;
    border: 1px solid rgb(204, 204, 204); /* 外层1px描边 */
    border-radius: var(--border-radius);
    overflow: hidden; /* 让圆角生效 */
}

.software-table table {
    width: 100%;
    border-collapse: collapse;
    border: none; /* 外边框由容器提供，避免双重边框 */
    border-radius: 0;
    overflow: hidden;
}

.software-table td {
    padding: 25px 24px;
    text-align: left;
    border-right: 1px solid var(--color-border-light);
    border-bottom: 1px solid var(--color-border-light);
    font-size: var(--font-size-md);
    font-weight: 400;
    color: var(--color-text);
    vertical-align: top;
}

.software-table a {
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 600;
    transition: var(--transition-fast);
}

.software-table a:hover {
    text-decoration: underline;
}

/* ========================================
   RESOURCES SECTION
   ======================================== */

.resources-section h2 {
    font-size: var(--font-size-5xl);
    font-weight: 200;
    line-height: 1.15;
    margin-bottom: 30px;
    color: var(--color-text);
}

.resources-section h3 {
    font-size: var(--font-size-4xl);
    font-weight: 300;
    line-height: 1.15;
    margin-bottom: var(--spacing-5xl);
    color: var(--color-text);
}

.resources-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-4xl);
}

.resource-card {
    background-color: #F1F7FB;
    border: 1px solid var(--color-primary);
    border-radius: var(--border-radius);
    padding: 43px 29px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.resource-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.resource-card h4 {
    font-size: var(--font-size-md);
    font-weight: 600;
    color: var(--color-text);
}

.resource-card svg {
    color: var(--color-primary);
    flex-shrink: 0;
}

/* ========================================
   FOOTER
   ======================================== */

.footer {
    background-color: #262626;
    color: var(--color-white);
}

.footer-top {
    background-color: var(--color-primary);
    padding: var(--spacing-6xl) 0;
}

.footer-top .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-top h2 {
    font-size: var(--font-size-4xl);
    font-weight: 300;
    line-height: 1.15;
    color: var(--color-white);
}

.footer-main {
    padding: var(--spacing-6xl) 0;
}

.footer-brand {
    margin-bottom: var(--spacing-5xl);
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-6xl);
}

.footer-column h4 {
    font-size: var(--font-size-md);
    font-weight: 600;
    margin-bottom: var(--spacing-xl);
    color: var(--color-white);
}

.footer-column ul {
    list-style: none;
}

.footer-column li {
    margin-bottom: var(--spacing-xl);
}

.footer-column a {
    color: var(--color-white);
    text-decoration: none;
    font-size: var(--font-size-sm);
    font-weight: 400;
    transition: var(--transition);
}

.footer-column a:hover {
    color: var(--color-primary);
}

.social-links {
    display: flex;
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 18px;
    height: 18px;
    color: var(--color-white);
    transition: var(--transition);
}

.social-links a:hover {
    color: var(--color-primary);
}

.footer-bottom {
    background-color: var(--color-black);
    padding: var(--spacing-4xl) 0;
}

.footer-bottom .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-bottom p {
    font-size: var(--font-size-sm);
    font-weight: 600;
    color: var(--color-white);
}

.footer-legal {
    display: flex;
    align-items: center;
    gap: 10px;
}

.footer-legal a {
    color: var(--color-white);
    text-decoration: none;
    font-size: var(--font-size-sm);
    font-weight: 600;
    transition: var(--transition);
}

.footer-legal a:hover {
    color: var(--color-primary);
}

.footer-legal span {
    color: var(--color-white);
    font-size: var(--font-size-sm);
}

.cookie-settings {
    background: none;
    border: 1px solid var(--color-white);
    color: var(--color-white);
    padding: 4px 8px;
    border-radius: var(--border-radius-sm);
    font-size: var(--font-size-sm);
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.cookie-settings:hover {
    background-color: var(--color-white);
    color: var(--color-black);
}

/* ========================================
   RESPONSIVE DESIGN
   ======================================== */

@media (max-width: 1200px) {
    .container {
        padding: 0 var(--spacing-4xl);
    }
    
    .nav {
        padding: 0 var(--spacing-4xl);
    }
    
    .product-showcase .container {
        grid-template-columns: 1fr;
        gap: var(--spacing-4xl);
    }
    
    .feature-content,
    .expert-content,
    .performance-content,
    .pci-content,
    .tfm-main-content,
    .twin-main-content,
    .applications-content,
    .omnipc-content,
    .weld-content,
    .weld-applications,
    .tofd-experience,
    .data-management,
    .demanding-environments,
    .corrosion-main-content,
    .corrosion-environment,
    .software-evolve,
    .black-box-app,
    .omnipc-intro {
        grid-template-columns: 1fr;
        gap: var(--spacing-4xl);
    }
    
    .tfm-text-content {
        padding-right: 0;
    }
    
    .twin-text-content {
        padding-left: 0;
    }
    
    .corrosion-text-content {
        padding-right: 0;
    }
    
    .techniques-grid {
        grid-template-columns: 1fr;
        gap: var(--spacing-2xl);
    }
    
    .video-demo {
        grid-template-columns: 1fr;
        gap: var(--spacing-2xl);
    }
    
    .api-fmc {
        grid-template-columns: 1fr;
        gap: var(--spacing-4xl);
    }
    
    .speed-features {
        grid-template-columns: 1fr;
        gap: var(--spacing-4xl);
    }
    
    .solutions-grid,
    .resources-grid {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .footer-links {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-4xl);
    }
}

@media (max-width: 768px) {
    body {
        padding-top: 65px; /* 确保有足够空间给固定头部 */
    }
    
    .container {
        padding: 0 var(--spacing-xl);
    }
    
    .nav {
        padding: 0 var(--spacing-xl);
        justify-content: space-between;
    }
    
    /* Hide desktop nav menu on mobile */
    .nav-menu {
        display: none;
    }
    
    /* Show center logo on mobile */
    .nav-center-logo {
        display: block;
        width: 150px;
        height: 30px;
    }
    
    /* Show mobile menu toggle */
    .mobile-menu-toggle {
        display: flex;
    }
    
    /* Show mobile menu */
    .mobile-menu {
        display: block;
    }
    
    /* Adjust nav actions for mobile */
    .nav-actions {
        gap: var(--spacing-md);
    }
    
    /* Hide some elements on mobile */
    .search-btn,
    .language-selector {
        display: none;
    }
    
    .wabtec-brand {
        display: none;
    }
    
    /* Hide desktop sub-nav menu on mobile */
    .sub-nav-menu {
        display: none;
    }
    
    /* Show mobile sub-nav dropdown */
    .mobile-sub-nav {
        display: block;
    }
    
    /* Fix mobile sub-nav positioning */
    .sub-nav {
        z-index: 1020 !important; /* 低于toolbar的z-index */
        position: sticky !important;
        top: 115px !important; /* header(65px) + toolbar(38px) + 间距(12px) = 115px */
    }
    
    .mobile-sub-nav-menu {
        z-index: 1010 !important; /* 低于sub-nav的z-index */
    }
    
    .sub-nav-link {
        padding: 12px 16px;
        font-size: var(--font-size-sm);
    }
    
    .product-title {
        font-size: var(--font-size-2xl);
    }
    
    .feature-text h2,
    .expert-text h2,
    .performance-text h2,
    .speed-content h2 {
        font-size: var(--font-size-2xl);
    }
    
    .applications-section h2,
    .specifications-section h2,
    .resources-section h2 {
        font-size: var(--font-size-3xl);
    }
    
    .applications-section h3,
    .specifications-section h3,
    .resources-section h3 {
        font-size: var(--font-size-2xl);
    }
    
    .applications-table {
        font-size: var(--font-size-base);
    }
    
    .applications-table th,
    .applications-table td {
        padding: 15px 12px;
    }
    
    .specs-table td {
        padding: 15px 12px;
        font-size: var(--font-size-base);
    }
    
    /* 移动端表格水平滚动 */
    .applications-table,
    .software-table,
    .specs-table {
        overflow-x: auto;
        -webkit-overflow-scrolling: touch;
    }
    
    .applications-table table,
    .software-table table,
    .specs-table table {
        min-width: 600px;
    }
    
    .footer-links {
        grid-template-columns: 1fr;
        gap: 30px;
    }
    
    .footer-bottom .container {
        flex-direction: column;
        gap: var(--spacing-xl);
        text-align: center;
    }
    
    .footer-legal {
        flex-wrap: wrap;
        justify-content: center;
    }
}

/* 确保桌面端样式 */
@media (min-width: 769px) {
    .mobile-menu-toggle {
        display: none !important;
    }
    
    .mobile-menu {
        display: none !important;
    }
    
    .nav-menu {
        display: flex !important;
    }
    
    .nav-center-logo {
        display: none !important;
    }
    
    .search-btn,
    .language-selector,
    .wabtec-brand {
        display: flex !important;
    }
    
    /* 确保桌面端sub-nav样式 */
    .sub-nav-menu {
        display: flex !important;
    }
    
    .mobile-sub-nav {
        display: none !important;
    }
    
    /* 确保桌面端sub-nav层级 */
    .sub-nav {
        z-index: 1000 !important; /* 低于toolbar的z-index */
        position: sticky !important;
        top: 117px !important; /* header(65px) + toolbar(40px) + 间距(12px) = 117px */
    }
    
    /* 确保桌面端toolbar样式 */
    .sub-nav-toolbar {
        background: #000 !important;
        padding: 10px 0 !important;
    }
    
    .sub-nav-toolbar .container {
        padding: 0 var(--spacing-6xl) !important;
        gap: 0 !important;
    }
    
    .toolbar-title {
        font-size: inherit !important;
        font-weight: 700 !important;
        line-height: inherit !important;
        flex: none !important;
    }
    
    .toolbar-actions {
        gap: 16px !important;
    }
    
    .toolbar-btn--ghost {
        display: inline-block !important;
    }
    
    .toolbar-btn--primary {
        padding: 8px 14px !important;
        font-size: 14px !important;
        font-weight: inherit !important;
        white-space: inherit !important;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    .nav {
        padding: 0 0;
    }
    
    .product-title {
        font-size: var(--font-size-xl);
    }
    
    .feature-text h2,
    .expert-text h2,
    .performance-text h2,
    .speed-content h2 {
        font-size: var(--font-size-xl);
    }
    
    .applications-section h2,
    .specifications-section h2,
    .resources-section h2 {
        font-size: var(--font-size-2xl);
    }
    
    .applications-section h3,
    .specifications-section h3,
    .resources-section h3 {
        font-size: var(--font-size-xl);
    }
    
    .cta-button {
        width: 100%;
        text-align: center;
    }
    
    .pci-buttons {
        flex-direction: column;
    }
    
    .resource-card {
        padding: 30px 20px;
    }
}

/* ========================================
   UTILITY CLASSES
   ======================================== */

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

.text-center {
    text-align: center;
}

.text-left {
    text-align: left;
}

.text-right {
    text-align: right;
}

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--spacing-xs); }
.mb-2 { margin-bottom: var(--spacing-sm); }
.mb-3 { margin-bottom: var(--spacing-md); }
.mb-4 { margin-bottom: var(--spacing-lg); }
.mb-5 { margin-bottom: var(--spacing-xl); }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--spacing-xs); }
.mt-2 { margin-top: var(--spacing-sm); }
.mt-3 { margin-top: var(--spacing-md); }
.mt-4 { margin-top: var(--spacing-lg); }
.mt-5 { margin-top: var(--spacing-xl); }