/* ==========================================================================
   Design System & Color Tokens (Executive Architectural & Building Materials Theme)
   ========================================================================== */
:root {
    --primary-blue: #0f172a;       /* Deep Slate Blue */
    --primary-accent: #2563eb;     /* Electric Royal Blue */
    --brand-gold: #f59e0b;         /* Vibrant Warm Gold */
    --brand-gold-dark: #d97706;    /* Rich Amber Gold */
    --text-primary: #0f172a;
    --text-secondary: #334155;
    --text-muted: #64748b;
    --bg-main: #f8fafc;
    --bg-white: #ffffff;
    --bg-dark: #0f172a;
    --border-light: #e2e8f0;
    --border-accent: #cbd5e1;
    --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 12px 28px -6px rgba(15, 23, 42, 0.1);
    --shadow-lg: 0 25px 40px -12px rgba(15, 23, 42, 0.18);
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: 'Noto Sans SC', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    color: var(--text-primary);
    background-color: var(--bg-main);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1240px;
    margin: 0 auto;
    padding: 0 24px;
}

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

/* ==========================================================================
   Top Contact Bar & Language Switcher
   ========================================================================== */
.top-bar {
    background-color: var(--primary-blue);
    color: #e2e8f0;
    font-size: 0.86rem;
    padding: 10px 0;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

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

.top-bar-contact {
    display: flex;
    gap: 28px;
}

.top-bar-contact a {
    color: #f1f5f9;
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 500;
    transition: var(--transition);
}

.top-bar-contact a:hover {
    color: var(--brand-gold);
}

.top-bar-contact i {
    color: var(--brand-gold);
}

.top-bar-right {
    display: flex;
    align-items: center;
    gap: 20px;
}

/* Language Selector Dropdown */
.lang-selector-wrapper {
    display: flex;
    align-items: center;
    gap: 8px;
    background: rgba(255, 255, 255, 0.12);
    padding: 4px 14px;
    border-radius: 30px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    color: #ffffff;
    transition: var(--transition);
}

.lang-selector-wrapper:hover {
    border-color: var(--brand-gold);
}

.lang-selector-wrapper i {
    color: var(--brand-gold);
    font-size: 14px;
}

.lang-select {
    background: transparent;
    border: none;
    color: #ffffff;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    outline: none;
}

.lang-select option {
    background-color: var(--primary-blue);
    color: #ffffff;
    font-weight: 500;
    padding: 8px;
}

/* ==========================================================================
   1. Header & Main Navbar
   ========================================================================== */
.navbar {
    position: sticky;
    top: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(12px);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
    z-index: 1000;
    transition: var(--transition);
}

.nav-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 86px;
}

.brand-logo {
    display: flex;
    align-items: center;
    gap: 14px;
    text-decoration: none;
}

.logo-badge {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #ffffff;
    border: 1.5px solid rgba(203, 213, 225, 0.8);
    box-shadow: 0 4px 14px rgba(15, 23, 42, 0.08);
    transition: var(--transition);
    padding: 2px;
}

.brand-logo:hover .logo-badge {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(37, 99, 235, 0.22);
    border-color: var(--primary-accent);
}

.brand-avatar {
    width: 100%;
    height: 100%;
    object-fit: cover;
    object-position: center 25%;
    border-radius: calc(var(--radius-md) - 3px);
}

.brand-text {
    display: flex;
    flex-direction: column;
}

.company-name-primary {
    font-weight: 700;
    font-size: 1.08rem;
    color: var(--primary-blue);
    letter-spacing: 0.3px;
    font-family: 'Inter', sans-serif;
}

.company-name-sub {
    font-size: 0.78rem;
    color: var(--text-muted);
    font-weight: 500;
}

.nav-links {
    display: flex;
    gap: 36px;
}

.nav-item {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 600;
    font-size: 1rem;
    padding: 8px 0;
    transition: var(--transition);
    position: relative;
}

.nav-item:hover, .nav-item.active {
    color: var(--primary-accent);
}

.nav-item::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-accent), var(--brand-gold));
    border-radius: 2px;
    transition: var(--transition);
}

.nav-item:hover::after, .nav-item.active::after {
    width: 100%;
}

.mobile-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 26px;
    color: var(--primary-blue);
    cursor: pointer;
}

/* ==========================================================================
   2. Hero Section / Banner (Crisp, High Impact, Glassmorphism Card)
   ========================================================================== */
.hero-section {
    position: relative;
    min-height: 85vh;
    background: url('images/hero_banner.jpg') center/cover no-repeat;
    display: flex;
    align-items: center;
    color: #ffffff;
    overflow: hidden;
}

/* Light transparent gradient overlay so background photography is sharp & vivid */
.hero-bg-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(15, 23, 42, 0.75) 0%, rgba(15, 23, 42, 0.4) 60%, rgba(15, 23, 42, 0.2) 100%);
}

.hero-content {
    position: relative;
    z-index: 10;
    padding: 80px 24px;
}

/* Frosted Glassmorphism Text Card Container */
.hero-text-box {
    max-width: 860px;
    background: rgba(15, 23, 42, 0.62);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid rgba(255, 255, 255, 0.18);
    border-radius: var(--radius-lg);
    padding: 48px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.35);
}

.hero-tag {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: rgba(245, 158, 11, 0.2);
    border: 1px solid rgba(245, 158, 11, 0.5);
    color: #fef08a;
    padding: 6px 20px;
    border-radius: 50px;
    font-size: 0.88rem;
    font-weight: 600;
    margin-bottom: 22px;
    backdrop-filter: blur(4px);
}

.hero-title {
    font-size: 2.85rem;
    font-weight: 800;
    line-height: 1.28;
    margin-bottom: 18px;
    color: #ffffff;
    letter-spacing: -0.5px;
}

.hero-subtitle {
    font-size: 1.15rem;
    color: #e2e8f0;
    margin-bottom: 36px;
    font-family: 'Inter', sans-serif;
    line-height: 1.7;
    font-weight: 400;
}

.hero-actions {
    display: flex;
    gap: 18px;
    flex-wrap: wrap;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    padding: 15px 34px;
    border-radius: var(--radius-md);
    font-weight: 700;
    font-size: 1rem;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
}

.btn-primary {
    background: linear-gradient(135deg, #f59e0b, #d97706);
    color: #ffffff;
    box-shadow: 0 8px 25px rgba(245, 158, 11, 0.4);
    border: none;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 30px rgba(245, 158, 11, 0.6);
    background: linear-gradient(135deg, #fbbf24, #d97706);
}

.btn-outline {
    background: rgba(255, 255, 255, 0.12);
    color: #ffffff;
    border: 1px solid rgba(255, 255, 255, 0.4);
    backdrop-filter: blur(6px);
}

.btn-outline:hover {
    background: rgba(255, 255, 255, 0.25);
    border-color: #ffffff;
    transform: translateY(-3px);
}

/* ==========================================================================
   Floating White Stats Banner (Modern Floating Card Row)
   ========================================================================== */
.stats-banner {
    background: #ffffff;
    box-shadow: 0 15px 35px rgba(15, 23, 42, 0.08);
    position: relative;
    z-index: 20;
    margin-top: -50px;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-light);
    padding: 32px 20px;
}

.stats-flex {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 24px;
    text-align: center;
}

.stat-box {
    padding: 10px 16px;
    border-right: 1px solid var(--border-light);
}

.stat-box:last-child {
    border-right: none;
}

.stat-num {
    font-size: 2.75rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--primary-accent), var(--brand-gold-dark));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    font-family: 'Inter', sans-serif;
    line-height: 1.1;
    margin-bottom: 6px;
}

.stat-label {
    font-size: 0.95rem;
    color: var(--text-secondary);
    font-weight: 600;
}

/* ==========================================================================
   General Section Layout & Section Headers
   ========================================================================== */
.section {
    padding: 95px 0;
}

.section-header {
    margin-bottom: 60px;
}

.section-badge {
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--brand-gold-dark);
    letter-spacing: 2px;
    text-transform: uppercase;
    display: block;
    margin-bottom: 8px;
}

.section-title {
    font-size: 2.3rem;
    font-weight: 800;
    color: var(--primary-blue);
    letter-spacing: -0.5px;
}

.section-subtitle {
    font-size: 1rem;
    color: var(--text-muted);
    font-family: 'Inter', sans-serif;
    margin-top: 4px;
}

.title-line {
    width: 64px;
    height: 4px;
    background: linear-gradient(90deg, var(--primary-accent), var(--brand-gold));
    margin: 16px auto 0;
    border-radius: 2px;
}

/* ==========================================================================
   3. Products / Categories Grid Section
   ========================================================================== */
.products-section {
    background: #ffffff;
}

.categories-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

.category-card {
    background: #ffffff;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-light);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    display: flex;
    flex-direction: column;
}

.category-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: #cbd5e1;
}

.category-img-box {
    position: relative;
    height: 190px;
    overflow: hidden;
}

.category-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.category-card:hover .category-img {
    transform: scale(1.08);
}

.category-tag {
    position: absolute;
    top: 12px;
    left: 12px;
    background: rgba(15, 23, 42, 0.88);
    color: var(--brand-gold);
    font-size: 0.75rem;
    font-weight: 700;
    padding: 4px 12px;
    border-radius: 20px;
    backdrop-filter: blur(4px);
}

.category-content {
    padding: 20px;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
}

.category-title {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary-blue);
    margin-bottom: 4px;
}

.category-cn {
    font-size: 0.86rem;
    color: var(--text-muted);
    margin-bottom: 14px;
}

.category-desc {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.65;
    margin-bottom: 18px;
}

.feature-bullets {
    list-style: none;
    margin-bottom: 22px;
}

.feature-bullets li {
    font-size: 0.9rem;
    color: var(--text-primary);
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.feature-bullets li i {
    color: var(--brand-gold-dark);
    font-size: 13px;
}

.card-link {
    margin-top: auto;
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--primary-accent);
    text-decoration: none;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.card-link:hover {
    color: var(--brand-gold-dark);
    transform: translateX(4px);
}

/* ==========================================================================
   4. About Us Section
   ========================================================================== */
.about-section {
    background: var(--bg-main);
}

.about-wrapper {
    display: grid;
    grid-template-columns: 1fr 1.2fr;
    gap: 50px;
    align-items: center;
}

.about-image-col {
    position: relative;
}

.image-frame {
    position: relative;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.about-img {
    width: 100%;
    height: 450px;
    object-fit: cover;
    display: block;
}

.image-overlay-badge {
    position: absolute;
    bottom: 24px;
    left: 24px;
    background: rgba(15, 23, 42, 0.92);
    color: #ffffff;
    padding: 16px 26px;
    border-radius: var(--radius-md);
    backdrop-filter: blur(8px);
    border-left: 5px solid var(--brand-gold);
}

.badge-num {
    display: block;
    font-size: 1.7rem;
    font-weight: 800;
    color: var(--brand-gold);
    font-family: 'Inter', sans-serif;
}

.badge-txt {
    font-size: 0.88rem;
    color: #e2e8f0;
}

.about-text-col {
    display: flex;
    flex-direction: column;
    gap: 26px;
}

.about-card {
    background: #ffffff;
    padding: 32px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-light);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.about-card:hover {
    box-shadow: var(--shadow-md);
    border-color: #cbd5e1;
}

.about-card-title {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--primary-blue);
    margin-bottom: 16px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.about-card-title i {
    color: var(--brand-gold-dark);
}

.about-paragraph {
    font-size: 1.02rem;
    color: var(--text-primary);
    line-height: 1.8;
    margin-bottom: 14px;
}

.about-paragraph:last-child {
    margin-bottom: 0;
}

.about-paragraph.cn-text {
    font-size: 0.98rem;
    color: var(--text-secondary);
}

/* ==========================================================================
   5. Cases & Applications Showcase
   ========================================================================== */
.cases-section {
    background: #ffffff;
}

.cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 32px;
}

.case-card {
    background: #ffffff;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-light);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.case-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.case-img-box {
    height: 240px;
    overflow: hidden;
}

.case-img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.6s ease;
}

.case-card:hover .case-img {
    transform: scale(1.08);
}

.case-info {
    padding: 24px;
}

.case-info h4 {
    font-size: 1.15rem;
    font-weight: 700;
    color: var(--primary-blue);
    margin-bottom: 8px;
}

.case-info p {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ==========================================================================
   6. Contact Section (Meta Verification Approved Card)
   ========================================================================== */
.contact-section {
    background: var(--bg-main);
}

.contact-intro {
    font-size: 1.12rem;
    color: var(--text-secondary);
    margin-top: 12px;
}

.verify-box {
    background: #ffffff;
    border: 2px solid var(--primary-accent);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    max-width: 980px;
    margin: 0 auto;
}

.verify-box-header {
    background: linear-gradient(135deg, var(--primary-blue), #1e293b);
    color: #ffffff;
    padding: 18px 32px;
    font-size: 1.05rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 12px;
}

.verify-box-header i {
    color: var(--brand-gold);
    font-size: 22px;
}

.contact-info-grid {
    padding: 40px;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(380px, 1fr));
    gap: 30px;
}

.info-card {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    padding: 24px;
    background: #ffffff;
    border: 1px solid var(--border-light);
    border-radius: var(--radius-md);
    transition: var(--transition);
}

.info-card.highlight {
    background: #f0f7ff;
    border-color: #bfdbfe;
}

.info-card:hover {
    box-shadow: var(--shadow-sm);
}

.info-icon {
    width: 52px;
    height: 52px;
    border-radius: var(--radius-md);
    background: rgba(37, 99, 235, 0.08);
    color: var(--primary-accent);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    flex-shrink: 0;
}

.info-details {
    display: flex;
    flex-direction: column;
}

.info-label {
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 6px;
}

.info-val-en {
    font-size: 1.08rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.45;
}

.info-val-cn {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-top: 4px;
    line-height: 1.45;
}

.info-val-highlight {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--primary-accent);
}

/* ==========================================================================
   7. Footer Section
   ========================================================================== */
.footer {
    background: var(--bg-dark);
    color: #94a3b8;
    padding: 42px 0;
    border-top: 1px solid #1e293b;
}

.footer-brand {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-bottom: 16px;
}

.footer-avatar {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    object-fit: cover;
    object-position: center 25%;
    background: #ffffff;
    padding: 2px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    border: 1px solid rgba(255, 255, 255, 0.15);
}

.footer-brand-name {
    font-weight: 700;
    font-size: 1.1rem;
    color: #ffffff;
    letter-spacing: 0.5px;
}

.copyright-line-1 {
    font-weight: 600;
    color: #f1f5f9;
    font-size: 0.98rem;
    margin-bottom: 6px;
}

.copyright-line-2 {
    font-size: 0.88rem;
    color: #64748b;
}

/* ==========================================================================
   Responsive Adaptations
   ========================================================================== */
@media (max-width: 992px) {
    .about-wrapper {
        grid-template-columns: 1fr;
    }

    .about-img {
        height: 340px;
    }

    .hero-text-box {
        padding: 36px;
    }

    .stat-box {
        border-right: none;
        border-bottom: 1px solid var(--border-light);
        padding-bottom: 16px;
    }

    .stat-box:last-child {
        border-bottom: none;
    }
}

@media (max-width: 768px) {
    .top-bar-container {
        flex-direction: column;
        gap: 10px;
        text-align: center;
    }

    .top-bar-right {
        justify-content: center;
    }

    .nav-links {
        position: absolute;
        top: 86px;
        left: 0;
        right: 0;
        background: #ffffff;
        flex-direction: column;
        padding: 24px 32px;
        box-shadow: 0 15px 30px rgba(0,0,0,0.1);
        display: none;
    }

    .nav-links.active {
        display: flex;
    }

    .mobile-toggle {
        display: block;
    }

    .hero-title {
        font-size: 2rem;
    }

    .hero-subtitle {
        font-size: 1rem;
    }

    .contact-info-grid {
        grid-template-columns: 1fr;
        padding: 24px;
    }

    .stats-banner {
        margin-top: 20px;
    }

    .categories-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 640px) {
    .categories-grid {
        grid-template-columns: 1fr;
    }
}