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

:root {
    --primary: #2563eb;
    --primary-dark: #1e40af;
    --accent: #10b981;
    --dark: #1f2937;
    --gray: #6b7280;
    --light-gray: #f3f4f6;
    --white: #ffffff;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Helvetica', 'Arial', sans-serif;
    line-height: 1.6;
    color: var(--dark);
    font-size: 16px;
}

html {
    scroll-behavior: smooth;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Navigation */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: var(--white);
    box-shadow: var(--shadow);
    z-index: 1000;
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 0;
}

.logo-img {
    height: 60px;
    width: auto;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 32px;
    align-items: center;
}

.nav-link {
    text-decoration: none;
    color: var(--dark);
    font-weight: 500;
    transition: color 0.2s;
}

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

.hamburger {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
}

.hamburger span {
    width: 24px;
    height: 3px;
    background: var(--dark);
    transition: 0.3s;
}

/* Hero Section */
.hero {
    padding: 140px 0 80px;
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
}

.hero-content {
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
}

.hero h1 {
    font-size: 48px;
    font-weight: 800;
    color: var(--dark);
    margin-bottom: 24px;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 20px;
    color: var(--gray);
    margin-bottom: 40px;
    line-height: 1.6;
}

.hero-cta {
    display: flex;
    gap: 16px;
    justify-content: center;
    margin-bottom: 48px;
}

.btn {
    padding: 14px 32px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-size: 16px;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-primary {
    background: var(--primary);
    color: var(--white);
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-secondary {
    background: var(--white);
    color: var(--primary);
    border: 2px solid var(--primary);
}

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

.btn-large {
    padding: 16px 40px;
    font-size: 18px;
}

.trust-badges {
    display: flex;
    gap: 40px;
    justify-content: center;
    flex-wrap: wrap;
}

.badge {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--gray);
    font-size: 14px;
}

.badge i {
    color: var(--accent);
    font-size: 20px;
}

/* Sections */
section {
    padding: 80px 0;
}

.section-intro {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 60px;
}

.section-intro h2 {
    font-size: 40px;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 16px;
}

.section-intro p {
    font-size: 18px;
    color: var(--gray);
}

/* Problem/Solution Section */
.solutions {
    background: var(--white);
}

.problems-solutions {
    display: flex;
    flex-direction: column;
    gap: 40px;
}

.ps-card {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 24px;
    align-items: center;
    padding: 32px;
    background: var(--light-gray);
    border-radius: 12px;
}

.problem, .solution {
    text-align: center;
}

.problem i {
    font-size: 40px;
    color: #ef4444;
    margin-bottom: 16px;
}

.solution i {
    font-size: 40px;
    color: var(--accent);
    margin-bottom: 16px;
}

.ps-card h3 {
    font-size: 20px;
    margin-bottom: 8px;
    color: var(--dark);
}

.ps-card p {
    color: var(--gray);
    font-size: 15px;
}

.arrow {
    font-size: 32px;
    color: var(--primary);
    font-weight: bold;
}

/* Why Us Section */
.why-us {
    background: var(--light-gray);
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 32px;
    margin-bottom: 60px;
}

.result-card {
    background: var(--white);
    padding: 32px;
    border-radius: 12px;
    text-align: center;
    box-shadow: var(--shadow);
}

.result-number {
    font-size: 48px;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: 12px;
}

.result-card h3 {
    font-size: 20px;
    margin-bottom: 12px;
    color: var(--dark);
}

.result-card p {
    color: var(--gray);
    font-size: 15px;
}

.why-details {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 32px;
}

.why-item {
    display: flex;
    gap: 16px;
}

.why-item i {
    font-size: 32px;
    color: var(--primary);
    flex-shrink: 0;
}

.why-item h4 {
    font-size: 18px;
    margin-bottom: 8px;
    color: var(--dark);
}

.why-item p {
    color: var(--gray);
    font-size: 15px;
}

/* Materials Section with Images */
.materials {
    background: var(--white);
}

.materials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 32px;
    margin-bottom: 60px;
}

.material-card {
    background: var(--white);
    border-radius: 12px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all 0.3s;
}

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

.material-image {
    width: 100%;
    height: 200px;
    overflow: hidden;
    background: var(--light-gray);
}

.material-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s;
}

/* Dual image layout for Fasteners */
.material-image-dual {
    width: 100%;
    height: 200px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2px;
    overflow: hidden;
    background: var(--light-gray);
}

.material-image-dual img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s;
}

.material-card:hover .material-image-dual img {
    transform: scale(1.05);
}

.material-card:hover .material-image img {
    transform: scale(1.05);
}

.material-card h3 {
    font-size: 20px;
    margin: 20px 20px 12px;
    color: var(--dark);
}

.benefit-list {
    list-style: none;
    padding: 0 20px 20px;
}

.benefit-list li {
    padding: 8px 0;
    color: var(--gray);
    font-size: 14px;
    position: relative;
    padding-left: 20px;
}

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

.custom-cta {
    text-align: center;
    padding: 48px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border-radius: 12px;
    color: var(--white);
}

.custom-cta h3 {
    font-size: 28px;
    margin-bottom: 12px;
}

.custom-cta p {
    font-size: 18px;
    margin-bottom: 24px;
    opacity: 0.9;
}

/* Social Proof */
.social-proof {
    background: var(--light-gray);
}

.testimonials {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 32px;
}

.testimonial {
    background: var(--white);
    padding: 32px;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.quote-icon {
    font-size: 48px;
    color: var(--primary);
    opacity: 0.2;
    line-height: 1;
    margin-bottom: 16px;
}

.testimonial p {
    font-size: 16px;
    color: var(--dark);
    margin-bottom: 20px;
    font-style: italic;
}

.author strong {
    display: block;
    color: var(--dark);
    margin-bottom: 4px;
}

.author span {
    color: var(--gray);
    font-size: 14px;
}

/* Contact Section */
.contact {
    background: var(--white);
}

.contact-wrapper {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
}

.contact-intro h2 {
    font-size: 36px;
    margin-bottom: 16px;
    color: var(--dark);
}

.large {
    font-size: 18px;
    color: var(--gray);
    margin-bottom: 32px;
}

.contact-benefits {
    margin-bottom: 40px;
}

.benefit {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
}

.benefit i {
    color: var(--accent);
    font-size: 18px;
}

.direct-contact {
    padding: 32px;
    background: var(--light-gray);
    border-radius: 12px;
}

.direct-contact h4 {
    margin-bottom: 24px;
    color: var(--dark);
    font-size: 20px;
}

.contact-method {
    display: flex;
    gap: 16px;
    margin-bottom: 24px;
}

.contact-method i {
    font-size: 24px;
    color: var(--primary);
    margin-top: 4px;
    flex-shrink: 0;
}

.contact-method strong {
    display: block;
    font-size: 14px;
    color: var(--gray);
    margin-bottom: 6px;
}

.contact-method a {
    color: var(--dark);
    text-decoration: none;
    font-weight: 500;
    display: block;
    margin-bottom: 4px;
}

.contact-method a:hover {
    color: var(--primary);
}

.contact-method span {
    color: var(--dark);
    font-weight: 500;
}

.social-links {
    margin-top: 32px;
    padding-top: 24px;
    border-top: 1px solid #e5e7eb;
}

.social-links h4 {
    margin-bottom: 16px;
    font-size: 16px;
}

.social-icons {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.social-icon {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--dark);
    text-decoration: none;
    padding: 8px;
    border-radius: 6px;
    transition: all 0.2s;
}

.social-icon:hover {
    background: var(--white);
    color: var(--primary);
}

.social-icon i {
    font-size: 20px;
}

/* Contact Image Side */
.contact-image {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px;
    background: var(--light-gray);
    border-radius: 12px;
}

.contact-logo {
    width: 200px;
    height: auto;
    margin-bottom: 40px;
}

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

.contact-cta h3 {
    font-size: 24px;
    margin-bottom: 16px;
    color: var(--dark);
}

.contact-cta p {
    color: var(--gray);
    margin-bottom: 24px;
    line-height: 1.6;
}

/* Footer */
.footer {
    background: var(--dark);
    color: var(--white);
    padding: 48px 0 24px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 48px;
    margin-bottom: 32px;
}

.footer-logo {
    height: 60px;
    width: auto;
    margin-bottom: 16px;
    background: white;
    padding: 8px;
    border-radius: 8px;
}

.footer-main p {
    opacity: 0.8;
    margin-bottom: 8px;
}

.company-legal {
    font-size: 14px;
    opacity: 0.7;
}

.company-legal-zh {
    font-size: 14px;
    opacity: 0.7;
}

.footer-contact h4 {
    margin-bottom: 16px;
}

.footer-contact p {
    opacity: 0.8;
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.footer-contact i {
    width: 16px;
}

.footer-bottom {
    text-align: center;
    padding-top: 24px;
    border-top: 1px solid rgba(255,255,255,0.1);
    opacity: 0.6;
    font-size: 14px;
}

/* Scroll to Top */
.scroll-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 48px;
    height: 48px;
    background: var(--primary);
    color: var(--white);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    transition: all 0.2s;
    z-index: 999;
}

.scroll-top:hover {
    transform: translateY(-4px);
}

.scroll-top.show {
    display: flex;
}

/* Responsive */
@media (max-width: 968px) {
    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 85px;
        flex-direction: column;
        background: var(--white);
        width: 100%;
        padding: 32px 0;
        box-shadow: var(--shadow);
        transition: 0.3s;
    }

    .nav-menu.active {
        left: 0;
    }

    .hero h1 {
        font-size: 36px;
    }

    .hero-cta {
        flex-direction: column;
        align-items: center;
    }

    .ps-card {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .arrow {
        transform: rotate(90deg);
    }

    .contact-wrapper {
        grid-template-columns: 1fr;
    }

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

    .materials-grid {
        grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    }
}

@media (max-width: 640px) {
    .hero h1 {
        font-size: 28px;
    }

    .section-intro h2 {
        font-size: 32px;
    }

    .trust-badges {
        gap: 20px;
    }

    .logo-img {
        height: 50px;
    }
}