/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary-color: #2ecc71;
    --secondary-color: #27ae60;
    --dark-color: #2c3e50;
    --light-color: #ecf0f1;
    --text-color: #333;
    --text-light: #7f8c8d;
    --white: #ffffff;
    --shadow: 0 5px 20px rgba(0,0,0,0.1);
    --shadow-hover: 0 8px 30px rgba(0,0,0,0.15);
    --transition: all 0.3s ease;
}

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-color);
    overflow-x: hidden;
}

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

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

.navbar.scrolled {
    box-shadow: var(--shadow-hover);
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
    cursor: pointer;
}

.logo i {
    margin-right: 10px;
    font-size: 1.8rem;
}

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

.nav-link {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
    padding: 5px 0;
}

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

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

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

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

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--text-color);
    transition: var(--transition);
}

/* 英雄区域 */
.hero {
    position: relative;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    overflow: hidden;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.3);
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: var(--white);
    animation: fadeInUp 1s ease;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.3);
}

.hero-subtitle {
    font-size: 1.3rem;
    margin-bottom: 2rem;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    padding: 12px 30px;
    border: none;
    border-radius: 50px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    text-decoration: none;
    display: inline-block;
    transition: var(--transition);
}

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

.btn-primary:hover {
    background: var(--secondary-color);
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(46, 204, 113, 0.4);
}

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

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

.btn-block {
    width: 100%;
}

.hero-scroll {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    color: var(--white);
    font-size: 2rem;
    animation: bounce 2s infinite;
    cursor: pointer;
}

/* 章节通用样式 */
section {
    padding: 80px 0;
}

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

.section-subtitle {
    color: var(--primary-color);
    font-weight: 600;
    font-size: 1rem;
    text-transform: uppercase;
    letter-spacing: 2px;
}

.section-title {
    font-size: 2.5rem;
    color: var(--dark-color);
    margin: 10px 0;
    font-weight: 700;
}

.title-underline {
    width: 80px;
    height: 4px;
    background: var(--primary-color);
    margin: 20px auto;
    border-radius: 2px;
}

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

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.about-image {
    position: relative;
}

.image-placeholder {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 20px;
    height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 8rem;
    box-shadow: var(--shadow);
}

.about-text h3 {
    font-size: 2rem;
    color: var(--dark-color);
    margin-bottom: 20px;
}

.about-text p {
    color: var(--text-light);
    margin-bottom: 15px;
    line-height: 1.8;
    font-size: 1.05rem;
}

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

.stat-item {
    text-align: center;
    padding: 20px;
    background: var(--white);
    border-radius: 10px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.stat-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 5px;
}

.stat-label {
    color: var(--text-light);
    font-size: 0.9rem;
}

/* 产品服务 */
.products {
    background: var(--white);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.product-card {
    background: var(--white);
    padding: 40px 30px;
    border-radius: 15px;
    box-shadow: var(--shadow);
    text-align: center;
    transition: var(--transition);
    border: 2px solid transparent;
}

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

.product-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    color: var(--white);
    font-size: 2rem;
    transition: var(--transition);
}

.product-card:hover .product-icon {
    transform: rotate(360deg);
}

.product-card h3 {
    font-size: 1.5rem;
    color: var(--dark-color);
    margin-bottom: 15px;
}

.product-card p {
    color: var(--text-light);
    line-height: 1.8;
}

/* 科技创新 */
.technology {
    background: var(--dark-color);
    color: var(--white);
}

.technology .section-subtitle {
    color: var(--primary-color);
}

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

.tech-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
}

.tech-item {
    position: relative;
    padding: 30px;
    background: rgba(255,255,255,0.05);
    border-radius: 15px;
    border-left: 4px solid var(--primary-color);
    transition: var(--transition);
}

.tech-item:hover {
    background: rgba(255,255,255,0.1);
    transform: translateX(10px);
}

.tech-number {
    font-size: 3rem;
    font-weight: 700;
    color: var(--primary-color);
    opacity: 0.3;
    margin-bottom: 10px;
}

.tech-item h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
}

.tech-item p {
    color: rgba(255,255,255,0.8);
    line-height: 1.8;
}

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

.contact-content {
    display: flex;
    justify-content: center;
    align-items: center;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 30px;
}

.info-item {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    padding: 25px;
    background: var(--white);
    border-radius: 10px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.info-item:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow-hover);
}

.info-icon {
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 1.3rem;
    flex-shrink: 0;
}

.info-text h4 {
    color: var(--dark-color);
    font-size: 1.2rem;
    margin-bottom: 5px;
}

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

.contact-form {
    background: var(--white);
    padding: 40px;
    border-radius: 15px;
    box-shadow: var(--shadow);
    width: 100%;
    max-width: 600px;
}

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

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 15px;
    border: 2px solid var(--light-color);
    border-radius: 10px;
    font-size: 1rem;
    font-family: inherit;
    transition: var(--transition);
}

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

.form-group textarea {
    resize: vertical;
}

/* 页脚 */
.footer {
    background: var(--dark-color);
    color: var(--white);
    padding: 60px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 20px;
    color: var(--white);
}

.footer-section p {
    color: rgba(255,255,255,0.7);
    line-height: 1.8;
}

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

.footer-section ul li {
    margin-bottom: 10px;
}

.footer-section ul li a {
    color: rgba(255,255,255,0.7);
    text-decoration: none;
    transition: var(--transition);
}

.footer-section ul li a:hover {
    color: var(--primary-color);
    padding-left: 5px;
}

.footer-section ul li i {
    margin-right: 10px;
    color: var(--primary-color);
}

.social-links {
    display: flex;
    gap: 15px;
    margin-top: 20px;
}

.social-links a {
    width: 40px;
    height: 40px;
    background: rgba(255,255,255,0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    transition: var(--transition);
}

.social-links a:hover {
    background: var(--primary-color);
    transform: translateY(-3px);
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255,255,255,0.1);
    color: rgba(255,255,255,0.7);
}

/* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: var(--white);
    border: none;
    border-radius: 50%;
    font-size: 1.5rem;
    cursor: pointer;
    box-shadow: var(--shadow);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 999;
}

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

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

/* 动画 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    40% {
        transform: translateX(-50%) translateY(-10px);
    }
    60% {
        transform: translateX(-50%) translateY(-5px);
    }
}

/* 响应式设计 */
@media (max-width: 968px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.1rem;
    }
    
    .about-content {
        grid-template-columns: 1fr;
    }
    
    .about-stats {
        grid-template-columns: repeat(3, 1fr);
    }
    
    .section-title {
        font-size: 2rem;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background: var(--white);
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: var(--shadow);
        padding: 20px 0;
    }
    
    .nav-menu.active {
        left: 0;
    }
    
    .hamburger {
        display: flex;
    }
    
    .hamburger.active span:nth-child(1) {
        transform: rotate(-45deg) translate(-5px, 6px);
    }
    
    .hamburger.active span:nth-child(2) {
        opacity: 0;
    }
    
    .hamburger.active span:nth-child(3) {
        transform: rotate(45deg) translate(-5px, -6px);
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .products-grid {
        grid-template-columns: 1fr;
    }
    
    .about-stats {
        grid-template-columns: 1fr;
    }
    
    .tech-features {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }
    
    section {
        padding: 60px 0;
    }
    
    .hero-buttons {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
}