/* 重置样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 性能优化 */
* {
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* 图片优化 */
img {
    max-width: 100%;
    height: auto;
    loading: lazy;
}

/* 关键CSS内联优化 */
.critical-css {
    display: block;
}

body {
    font-family: 'Microsoft YaHei', Arial, sans-serif;
    line-height: 1.6;
    color: #333;
    overflow-x: hidden;
}

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

/* 导航栏 */
.navbar {
    background: #fff;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    transition: all 0.3s ease;
}

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

.nav-logo h2 {
    color: #2c5aa0;
    font-size: 24px;
    font-weight: bold;
}

.nav-menu {
    display: flex;
    gap: 30px;
}

.nav-link {
    text-decoration: none;
    color: #333;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link:hover {
    color: #2c5aa0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: #2c5aa0;
    transition: width 0.3s ease;
}

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

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

.bar {
    width: 25px;
    height: 3px;
    background: #333;
    margin: 3px 0;
    transition: 0.3s;
}

/* 首页横幅 */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 100px 0 50px;
    color: white;
    position: relative;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: url('images/photo-1586023492125-27b2c045efd7.jfif') center/cover;
    z-index: -2;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.8) 0%, rgba(118, 75, 162, 0.8) 100%);
    z-index: -1;
}

.hero-content {
    flex: 1;
    max-width: 600px;
    padding: 0 20px;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 20px;
    font-weight: bold;
    line-height: 1.2;
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 30px;
    opacity: 0.9;
}

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

.btn {
    padding: 15px 30px;
    border: none;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    cursor: pointer;
    display: inline-block;
    text-align: center;
}

.btn-primary {
    background: #fff;
    color: #2c5aa0;
}

.btn-primary:hover {
    background: #f0f0f0;
    transform: translateY(-2px);
}

.btn-secondary {
    background: transparent;
    color: #fff;
    border: 2px solid #fff;
}

.btn-secondary:hover {
    background: #fff;
    color: #2c5aa0;
    transform: translateY(-2px);
}

.hero-image {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 0 20px;
}

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

.showcase-item {
    position: relative;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0,0,0,0.3);
    transition: transform 0.3s ease;
}

.showcase-item:hover {
    transform: translateY(-10px);
}

.showcase-item img {
    width: 200px;
    height: 150px;
    object-fit: cover;
    display: block;
    border-radius: 10px;
}

.showcase-item span {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: linear-gradient(transparent, rgba(0,0,0,0.8));
    color: white;
    padding: 20px 10px 10px;
    text-align: center;
    font-weight: 600;
    border-radius: 0 0 10px 10px;
}

/* 关于我们 */
.about {
    padding: 80px 0;
    background: #f8f9fa;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 50px;
    color: #2c5aa0;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: #2c5aa0;
    border-radius: 2px;
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
    align-items: center;
}

.about-text h3 {
    font-size: 1.8rem;
    margin-bottom: 20px;
    color: #333;
}

.about-text p {
    font-size: 1.1rem;
    margin-bottom: 30px;
    color: #666;
    line-height: 1.8;
}

.about-features {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.feature {
    text-align: center;
    padding: 20px;
    background: #fff;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
}

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

.feature i {
    font-size: 2rem;
    color: #2c5aa0;
    margin-bottom: 15px;
}

.feature h4 {
    font-size: 1.1rem;
    margin-bottom: 10px;
    color: #333;
}

.feature p {
    font-size: 0.9rem;
    color: #666;
    margin: 0;
}

.about-image {
    display: flex;
    justify-content: center;
}

.team-photo {
    position: relative;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 15px 35px rgba(0,0,0,0.1);
    width: 100%;
    max-width: 400px;
}

.team-photo img {
    width: 100%;
    height: 300px;
    object-fit: cover;
    display: block;
}

.team-overlay {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    background: linear-gradient(transparent, rgba(44, 90, 160, 0.9));
    color: white;
    padding: 30px 20px 20px;
    text-align: center;
}

.team-overlay h4 {
    font-size: 1.3rem;
    margin-bottom: 5px;
}

.team-overlay p {
    font-size: 1rem;
    opacity: 0.9;
    margin: 0;
}

/* 服务项目 */
.services {
    padding: 80px 0;
    background: #fff;
}

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

.service-card {
    text-align: center;
    padding: 40px 20px;
    background: #f8f9fa;
    border-radius: 15px;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.service-card:hover {
    transform: translateY(-10px);
    border-color: #2c5aa0;
    box-shadow: 0 15px 30px rgba(44, 90, 160, 0.2);
}

.service-icon {
    width: 80px;
    height: 80px;
    background: #2c5aa0;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
}

.service-icon i {
    font-size: 2rem;
    color: #fff;
}

.service-card h3 {
    font-size: 1.3rem;
    margin-bottom: 15px;
    color: #333;
}

.service-card p {
    color: #666;
    line-height: 1.6;
}

/* 案例展示 */
.portfolio {
    padding: 80px 0;
    background: #f8f9fa;
}

.portfolio-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
}

.portfolio-item {
    background: #fff;
    border-radius: 15px;
    overflow: hidden;
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
}

.portfolio-item:hover {
    transform: translateY(-5px);
}

.portfolio-image {
    height: 200px;
    overflow: hidden;
    position: relative;
}

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

.portfolio-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(44, 90, 160, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.portfolio-item:hover .portfolio-overlay {
    opacity: 1;
}

.portfolio-item:hover .portfolio-image img {
    transform: scale(1.1);
}

.portfolio-overlay i {
    font-size: 2rem;
    color: white;
}

.portfolio-info {
    padding: 20px;
}

.portfolio-info h3 {
    font-size: 1.2rem;
    margin-bottom: 10px;
    color: #333;
}

.portfolio-info p {
    color: #666;
    font-size: 0.9rem;
}

/* 联系我们 */
.contact {
    padding: 80px 0;
    background: #fff;
}

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

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

.contact-item {
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 10px;
    transition: all 0.3s ease;
}

.contact-item:hover {
    background: #e9ecef;
    transform: translateX(10px);
}

.contact-item i {
    font-size: 1.5rem;
    color: #2c5aa0;
    width: 30px;
}

.contact-item h4 {
    font-size: 1.1rem;
    margin-bottom: 5px;
    color: #333;
}

.contact-item p {
    color: #666;
    margin: 0;
}

.contact-form {
    background: #f8f9fa;
    padding: 40px;
    border-radius: 15px;
}

.contact-form h3 {
    font-size: 1.5rem;
    margin-bottom: 30px;
    color: #333;
    text-align: center;
}

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

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 15px;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #2c5aa0;
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

/* 页脚 */
.footer {
    background: #2c3e50;
    color: #fff;
    padding: 50px 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 30px;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 20px;
    color: #fff;
}

.footer-section p {
    color: #bdc3c7;
    line-height: 1.6;
    margin-bottom: 10px;
}

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

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

.footer-section ul li a {
    color: #bdc3c7;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section ul li a:hover {
    color: #fff;
}

.footer-bottom {
    text-align: center;
    padding-top: 20px;
    border-top: 1px solid #34495e;
    color: #bdc3c7;
}

/* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: #2c5aa0;
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 1000;
}

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

.back-to-top:hover {
    background: #1e3d72;
    transform: translateY(-3px);
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: #fff;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px rgba(0,0,0,0.05);
        padding: 20px 0;
    }

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

    .nav-toggle {
        display: flex;
    }

    .nav-toggle.active .bar:nth-child(2) {
        opacity: 0;
    }

    .nav-toggle.active .bar:nth-child(1) {
        transform: translateY(8px) rotate(45deg);
    }

    .nav-toggle.active .bar:nth-child(3) {
        transform: translateY(-8px) rotate(-45deg);
    }

    .hero {
        flex-direction: column;
        text-align: center;
        padding: 120px 0 50px;
    }

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

    .hero-buttons {
        justify-content: center;
    }

    .about-content {
        grid-template-columns: 1fr;
        gap: 30px;
    }

    .about-features {
        grid-template-columns: 1fr;
        gap: 15px;
    }

    .contact-content {
        grid-template-columns: 1fr;
        gap: 30px;
    }

    .hero-showcase {
        flex-direction: column;
        align-items: center;
    }
    
    .showcase-item img {
        width: 250px;
        height: 180px;
    }
    
    .team-photo img {
        height: 250px;
    }

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

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

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

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

    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .hero h1 {
        font-size: 2rem;
    }

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

    .btn {
        padding: 12px 25px;
        font-size: 0.9rem;
    }

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

    .service-card,
    .contact-form {
        padding: 30px 20px;
    }

    .section-title {
        font-size: 1.8rem;
    }
}

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

.fade-in-up {
    animation: fadeInUp 0.6s ease-out;
}

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