:root {
    --primary-dark: #1a365d;
    --primary-blue: #3182ce;
    --metal-gray: #718096;
    --light-gray: #e2e8f0;
    --bg-light: #f7fafc;
    --white: #ffffff;
    --accent-gold: #d69e2e;
    --text-dark: #2d3748;
    --text-light: #a0aec0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background: var(--bg-light);
}

a {
    text-decoration: none;
    color: inherit;
}

ul {
    list-style: none;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.navbar.scrolled {
    background: var(--primary-dark);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo svg {
    width: 45px;
    height: 45px;
}

.logo-text {
    font-size: 20px;
    font-weight: 700;
    color: var(--primary-dark);
    transition: var(--transition);
}

.navbar.scrolled .logo-text {
    color: var(--white);
}

.nav-menu {
    display: flex;
    gap: 40px;
}

.nav-menu a {
    font-size: 15px;
    font-weight: 500;
    color: var(--text-dark);
    position: relative;
    padding: 5px 0;
    transition: var(--transition);
}

.navbar.scrolled .nav-menu a {
    color: var(--white);
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-gold);
    transition: var(--transition);
}

.nav-menu a:hover::after {
    width: 100%;
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    padding: 10px;
}

.mobile-menu-btn span {
    width: 25px;
    height: 2px;
    background: var(--primary-dark);
    transition: var(--transition);
}

.navbar.scrolled .mobile-menu-btn span {
    background: var(--white);
}

.banner {
    position: relative;
    height: 100vh;
    min-height: 600px;
    overflow: hidden;
}

.banner-slides {
    position: relative;
    height: 100%;
}

.banner-slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 0.8s ease;
}

.banner-slide.active {
    opacity: 1;
}

.banner-slide img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.banner-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(26, 54, 93, 0.85) 0%, rgba(49, 130, 206, 0.7) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
}

.banner-content {
    text-align: center;
    color: var(--white);
    max-width: 800px;
    padding: 20px;
}

.banner-content h1 {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.banner-content p {
    font-size: 20px;
    margin-bottom: 30px;
    opacity: 0.95;
}

.banner-btn {
    display: inline-block;
    padding: 15px 40px;
    background: var(--accent-gold);
    color: var(--primary-dark);
    font-size: 16px;
    font-weight: 600;
    border-radius: 4px;
    transition: var(--transition);
}

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

.banner-dots {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 12px;
}

.banner-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.5);
    cursor: pointer;
    transition: var(--transition);
}

.banner-dot.active {
    background: var(--accent-gold);
    transform: scale(1.2);
}

.banner-arrows {
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    transform: translateY(-50%);
    display: flex;
    justify-content: space-between;
    padding: 0 20px;
    pointer-events: none;
}

.banner-arrow {
    width: 50px;
    height: 50px;
    background: rgba(255, 255, 255, 0.2);
    border: none;
    border-radius: 50%;
    color: var(--white);
    font-size: 24px;
    cursor: pointer;
    transition: var(--transition);
    pointer-events: auto;
    display: flex;
    align-items: center;
    justify-content: center;
}

.banner-arrow:hover {
    background: var(--accent-gold);
    color: var(--primary-dark);
}

.products {
    padding: 80px 0;
    background: var(--white);
}

.section-header {
    text-align: center;
    margin-bottom: 50px;
}

.section-header h2 {
    font-size: 36px;
    color: var(--primary-dark);
    margin-bottom: 15px;
    position: relative;
    display: inline-block;
}

.section-header h2::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: var(--accent-gold);
}

.section-header p {
    color: var(--metal-gray);
    font-size: 16px;
    margin-top: 20px;
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}

.product-card {
    background: var(--white);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.product-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
}

.product-image {
    position: relative;
    height: 200px;
    overflow: hidden;
    background: var(--bg-light);
}

.product-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.product-card:hover .product-image img {
    transform: scale(1.1);
}

.product-info {
    padding: 20px;
}

.product-info h3 {
    font-size: 18px;
    color: var(--primary-dark);
    margin-bottom: 10px;
}

.product-info p {
    font-size: 14px;
    color: var(--metal-gray);
    line-height: 1.6;
}

.view-more {
    text-align: center;
    margin-top: 50px;
}

.view-more a {
    display: inline-block;
    padding: 12px 35px;
    border: 2px solid var(--primary-blue);
    color: var(--primary-blue);
    font-weight: 500;
    border-radius: 4px;
    transition: var(--transition);
}

.view-more a:hover {
    background: var(--primary-blue);
    color: var(--white);
}

.about-advantage {
    padding: 80px 0;
    background: var(--bg-light);
}

.about-advantage-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
}

.about-section, .advantage-section {
    background: var(--white);
    border-radius: 8px;
    padding: 40px;
    box-shadow: var(--shadow);
}

.section-title {
    font-size: 24px;
    color: var(--primary-dark);
    margin-bottom: 25px;
    padding-bottom: 15px;
    border-bottom: 2px solid var(--accent-gold);
}

.about-content p {
    color: var(--text-dark);
    line-height: 1.8;
    margin-bottom: 15px;
}

.about-content img {
    width: 100%;
    height: 200px;
    object-fit: cover;
    border-radius: 8px;
    margin-top: 20px;
}

.advantage-list {
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.advantage-item {
    display: flex;
    gap: 20px;
    align-items: flex-start;
}

.advantage-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-dark), var(--primary-blue));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.advantage-icon svg {
    width: 30px;
    height: 30px;
    fill: var(--white);
}

.advantage-text h4 {
    font-size: 18px;
    color: var(--primary-dark);
    margin-bottom: 8px;
}

.advantage-text p {
    font-size: 14px;
    color: var(--metal-gray);
    line-height: 1.6;
}

.cases {
    padding: 80px 0;
    background: var(--white);
}

.cases-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.case-card {
    position: relative;
    border-radius: 8px;
    overflow: hidden;
    height: 250px;
    cursor: pointer;
}

.case-card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.case-card:hover img {
    transform: scale(1.1);
}

.case-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    padding: 20px;
    background: linear-gradient(transparent, rgba(26, 54, 93, 0.9));
    color: var(--white);
}

.case-overlay h4 {
    font-size: 18px;
    margin-bottom: 5px;
}

.case-overlay p {
    font-size: 14px;
    opacity: 0.9;
}

.contact {
    padding: 80px 0;
    background: var(--primary-dark);
    color: var(--white);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
}

.contact-info h3 {
    font-size: 24px;
    margin-bottom: 30px;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 15px;
    margin-bottom: 25px;
}

.contact-item svg {
    width: 24px;
    height: 24px;
    fill: var(--accent-gold);
    flex-shrink: 0;
    margin-top: 3px;
}

.contact-item p {
    font-size: 15px;
    line-height: 1.6;
}

.contact-form h3 {
    font-size: 24px;
    margin-bottom: 30px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 15px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 4px;
    background: rgba(255, 255, 255, 0.1);
    color: var(--white);
    font-size: 15px;
    transition: var(--transition);
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: rgba(255, 255, 255, 0.6);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--accent-gold);
    background: rgba(255, 255, 255, 0.15);
}

.form-group textarea {
    height: 120px;
    resize: none;
}

.submit-btn {
    width: 100%;
    padding: 15px;
    background: var(--accent-gold);
    color: var(--primary-dark);
    border: none;
    border-radius: 4px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

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

.footer {
    padding: 30px 0;
    background: #0d1f33;
    text-align: center;
    color: var(--text-light);
    font-size: 14px;
}

.footer a {
    color: var(--accent-gold);
}

.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-blue);
    color: var(--white);
    border: none;
    border-radius: 50%;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-5px);
}

@media (max-width: 1024px) {
    .products-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .cases-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--white);
        flex-direction: column;
        padding: 20px;
        gap: 15px;
        box-shadow: var(--shadow);
        display: none;
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .navbar.scrolled .nav-menu {
        background: var(--primary-dark);
    }
    
    .mobile-menu-btn {
        display: flex;
    }
    
    .banner-content h1 {
        font-size: 32px;
    }
    
    .banner-content p {
        font-size: 16px;
    }
    
    .products-grid {
        grid-template-columns: 1fr;
    }
    
    .about-advantage-grid {
        grid-template-columns: 1fr;
    }
    
    .cases-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-grid {
        grid-template-columns: 1fr;
    }
    
    .section-header h2 {
        font-size: 28px;
    }
}