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

:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --accent-color: #3b82f6;
    --text-color: #1f2937;
    --light-text: #6b7280;
    --bg-color: #ffffff;
    --light-bg: #f9fafb;
    --border-color: #e5e7eb;
    --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: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
}

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

/* 导航栏 */
.navbar {
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    box-shadow: var(--shadow);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: relative;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    letter-spacing: -0.5px;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
}

.nav-menu a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s;
}

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

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

.hamburger span {
    width: 25px;
    height: 2px;
    background-color: var(--text-color);
    transition: 0.3s;
}

/* 语言选择器 */
.language-selector {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    margin-left: 1rem;
    font-size: 0.9rem;
}

.lang-btn {
    background: none;
    border: none;
    padding: 0.4rem 0.8rem;
    cursor: pointer;
    font-size: 0.9rem;
    color: var(--light-text);
    transition: color 0.3s, background-color 0.3s;
    font-family: inherit;
}

.lang-btn:hover {
    color: var(--primary-color);
}

.lang-btn.active {
    color: var(--primary-color);
    font-weight: 600;
}

.lang-divider {
    color: var(--border-color);
    font-weight: 300;
}

/* 首页横幅 */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding-top: 80px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="40" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="1"/><circle cx="50" cy="50" r="30" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="1"/><circle cx="50" cy="50" r="20" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="1"/></svg>');
    opacity: 0.3;
    animation: rotate 60s linear infinite;
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.hero-content {
    flex: 1;
    color: white;
    padding: 0 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.hero h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero p {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.hero-image {
    flex: 1;
    height: 400px;
    background: linear-gradient(135deg, rgba(255,255,255,0.1) 0%, rgba(255,255,255,0.05) 100%);
    border-radius: 20px;
    margin: 0 20px;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-image::after {
    content: '🧬';
    font-size: 150px;
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
}

.btn-primary {
    display: inline-block;
    background-color: white;
    color: var(--primary-color);
    padding: 1rem 2rem;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: transform 0.3s, box-shadow 0.3s;
    border: none;
    cursor: pointer;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

/* 通用区块样式 */
section {
    padding: 100px 0;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.section-subtitle {
    text-align: center;
    color: var(--light-text);
    font-size: 1.1rem;
    margin-bottom: 4rem;
}

/* 产品中心 */
.products {
    background-color: var(--light-bg);
}

.product-categories {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
}

.product-card {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    box-shadow: var(--shadow);
    transition: transform 0.3s, box-shadow 0.3s;
}

.product-card {
    background: white;
    padding: 2rem;
    border-radius: 16px;
    box-shadow: var(--shadow);
    transition: transform 0.3s, box-shadow 0.3s;
    text-decoration: none;
    display: block;
    color: inherit;
}

.product-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.product-card::after {
    content: 'View Details →';
    display: block;
    margin-top: 1rem;
    color: var(--primary-color);
    font-size: 0.85rem;
    opacity: 0;
    transition: opacity 0.3s;
    font-weight: 500;
}

.product-card:hover::after {
    opacity: 1;
}

.product-card * {
    pointer-events: none;
}

.product-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.product-card h3 {
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.product-card > p {
    color: var(--light-text);
    margin-bottom: 1.5rem;
}

.product-list ul {
    list-style: none;
    padding-left: 0;
}

.product-list li {
    padding: 0.75rem 0;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-color);
    font-size: 0.95rem;
}

.product-list li:last-child {
    border-bottom: none;
}

/* 关于我们 */
.about {
    background-color: var(--bg-color);
}

.about-content {
    display: flex;
    align-items: center;
    gap: 4rem;
}

.about-text {
    flex: 1;
}

.about-text h3 {
    font-size: 1.75rem;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.about-text p {
    color: var(--light-text);
    margin-bottom: 1rem;
    line-height: 1.8;
}

.about-image {
    flex: 1;
    height: 400px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 16px;
    position: relative;
    display: flex;
    align-items: center;
    justify-content: center;
}

.about-image::after {
    content: '🏢';
    font-size: 120px;
}

.features {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
    margin-top: 2rem;
}

.feature-item {
    padding: 1rem;
    border-left: 3px solid var(--primary-color);
}

.feature-icon {
    color: var(--primary-color);
    font-weight: 700;
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.feature-item h4 {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    color: var(--text-color);
}

.feature-item p {
    color: var(--light-text);
    font-size: 0.9rem;
}

/* 联系我们 */
.contact {
    background-color: var(--light-bg);
}

.contact-content {
    display: flex;
    gap: 4rem;
}

.contact-info {
    flex: 1;
}

.contact-item {
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: white;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.contact-icon {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.contact-item h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
    color: var(--text-color);
}

.contact-item p {
    color: var(--light-text);
}

.contact-form {
    flex: 1;
    background: white;
    padding: 2rem;
    border-radius: 16px;
    box-shadow: var(--shadow);
}

.contact-form h3 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.contact-form input,
.contact-form textarea {
    width: 100%;
    padding: 1rem;
    margin-bottom: 1rem;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    font-family: inherit;
    transition: border-color 0.3s;
}

.contact-form input:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.contact-form button {
    width: 100%;
    padding: 1rem;
    font-size: 1rem;
}

/* 页脚 */
.footer {
    background-color: #1f2937;
    color: white;
    padding: 4rem 0 2rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
}

.footer-section p {
    color: #9ca3af;
    line-height: 1.6;
}

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

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: #9ca3af;
    text-decoration: none;
    transition: color 0.3s;
}

.footer-section a:hover {
    color: white;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid #374151;
    color: #9ca3af;
}

/* 响应式设计 */
@media (max-width: 968px) {
    .hero {
        flex-direction: column;
        text-align: center;
        padding-top: 120px;
    }

    .hero h1 {
        font-size: 2.5rem;
    }

    .hero-image {
        height: 300px;
        margin-top: 2rem;
    }

    .about-content {
        flex-direction: column;
    }

    .about-image {
        height: 300px;
    }

    .contact-content {
        flex-direction: column;
    }

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

    .hamburger {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        padding: 2rem 0;
        transition: 0.3s;
        box-shadow: var(--shadow);
    }

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

    .language-selector {
        position: absolute;
        top: 70px;
        right: 20px;
        background-color: white;
        padding: 0.5rem 1rem;
        border-radius: 8px;
        box-shadow: var(--shadow);
        z-index: 1001;
    }
}

@media (max-width: 640px) {
    .hero h1 {
        font-size: 2rem;
    }

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

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

    .product-categories {
        grid-template-columns: 1fr;
    }

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

/* 平滑滚动 */
html {
    scroll-behavior: smooth;
}

/* 加载动画 */
.fade-in {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}