/* 基础样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #0066cc;
    --primary-dark: #004d99;
    --secondary-color: #00a8e8;
    --text-color: #333;
    --text-light: #666;
    --bg-light: #f8f9fa;
    --white: #fff;
    --shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
}

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

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--white);
    box-shadow: var(--shadow);
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

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

.logo-icon {
    font-size: 28px;
}

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

.nav-menu {
    display: flex;
    list-style: none;
    gap: 30px;
}

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

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width 0.3s;
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    cursor: pointer;
    gap: 5px;
}

.nav-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-color);
    transition: 0.3s;
}

/* Hero 区域 */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    background: linear-gradient(135deg, #e8f4fc 0%, #d0e8f5 100%);
    padding: 100px 20px 60px;
    overflow: hidden;
}

.hero-content {
    text-align: center;
    z-index: 1;
    max-width: 800px;
}

.hero-title {
    font-size: clamp(28px, 5vw, 48px);
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 20px;
}

.hero-subtitle {
    font-size: clamp(16px, 2.5vw, 20px);
    color: var(--text-light);
    margin-bottom: 40px;
}

.hero-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

/* 产品介绍 */
.products {
    padding: 80px 20px;
    background: var(--bg-light);
}

.product-list {
    display: flex;
    flex-direction: column;
    gap: 60px;
}

.product-item {
    display: flex;
    align-items: center;
    gap: 50px;
    background: var(--white);
    border-radius: 20px;
    overflow: hidden;
    box-shadow: var(--shadow);
}

.product-item.reverse {
    flex-direction: row-reverse;
}

.product-image {
    flex: 0 0 280px;
    padding: 30px;
    display: flex;
    justify-content: center;
    align-items: center;
    background: linear-gradient(135deg, #f0f7fc 0%, #e5f1f8 100%);
}

.product-image img {
    max-width: 100%;
    max-height: 350px;
    width: auto;
    height: auto;
    object-fit: contain;
    border-radius: 12px;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
}

.product-info {
    flex: 1;
    padding: 40px;
}

.product-info h3 {
    font-size: clamp(18px, 2.5vw, 24px);
    color: var(--primary-color);
    margin-bottom: 20px;
}

.product-info ul {
    list-style: none;
}

.product-info li {
    padding: 10px 0;
    padding-left: 28px;
    position: relative;
    color: var(--text-light);
    line-height: 1.8;
}

.product-info li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--secondary-color);
    font-weight: bold;
}

/* 关于我们 */
.about {
    padding: 80px 20px;
    background: linear-gradient(135deg, #0066cc 0%, #00a8e8 100%);
    color: var(--white);
}

.about .section-title {
    color: var(--white);
}

.about .section-title::after {
    background: var(--white);
}

.about-content {
    max-width: 800px;
    margin: 50px auto 0;
}

.about-text p {
    margin-bottom: 20px;
    font-size: 16px;
    line-height: 2;
    opacity: 0.95;
}

.about-text .highlight {
    font-size: 20px;
    font-weight: 500;
    text-align: center;
    margin-top: 30px;
}

/* 联系我们 */
.contact {
    padding: 80px 20px;
    background: var(--white);
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.contact-card {
    text-align: center;
    padding: 40px 30px;
    background: var(--bg-light);
    border-radius: 16px;
    transition: transform 0.3s;
}

.contact-card:hover {
    transform: translateY(-5px);
}

.contact-icon {
    font-size: 40px;
    margin-bottom: 20px;
}

.contact-card h3 {
    color: var(--primary-color);
    margin-bottom: 15px;
}

.contact-card a {
    color: var(--text-color);
    text-decoration: none;
    font-size: 18px;
}

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

/* 页脚 */
.footer {
    background: var(--text-color);
    color: var(--white);
    padding: 30px 20px;
    text-align: center;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        position: absolute;
        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;
    }

    .product-item,
    .product-item.reverse {
        flex-direction: column;
    }

    .product-image {
        flex: none;
        width: 100%;
        padding: 30px 20px;
    }

    .product-image img {
        max-height: 280px;
    }

    .product-info {
        padding: 30px 20px;
    }

    .hero {
        min-height: auto;
        padding: 120px 20px 80px;
    }
}

@media (max-width: 480px) {
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }

    .btn {
        width: 200px;
        text-align: center;
    }

    .product-image img {
        max-height: 220px;
    }

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

    .feature-card {
        padding: 25px 15px;
    }

    .feature-icon {
        font-size: 36px;
    }
}

.btn {
    padding: 14px 32px;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s;
    display: inline-block;
}

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

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

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

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

/* 通用标题 */
.section-title {
    text-align: center;
    font-size: clamp(24px, 4vw, 36px);
    color: var(--primary-color);
    margin-bottom: 20px;
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 3px;
    background: var(--secondary-color);
    margin: 15px auto 0;
}

.section-desc {
    text-align: center;
    color: var(--text-light);
    max-width: 600px;
    margin: 0 auto 50px;
}

/* 特色功能 */
.features {
    padding: 80px 20px;
    background: var(--white);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 30px;
    margin-top: 50px;
}

.feature-card {
    text-align: center;
    padding: 40px 20px;
    background: var(--bg-light);
    border-radius: 16px;
    transition: transform 0.3s, box-shadow 0.3s;
}

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

.feature-icon {
    font-size: 48px;
    margin-bottom: 20px;
}

.feature-card h3 {
    color: var(--primary-color);
    margin-bottom: 10px;
}