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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* 预加载关键资源 */
.preload {
    position: absolute;
    left: -9999px;
    visibility: hidden;
}

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

/* 减少重绘 */
.gpu-accelerated {
    transform: translateZ(0);
    will-change: transform;
}

html {
    scroll-behavior: smooth;
}

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

/* 导航栏样式 */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
    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-weight: 700;
    font-size: 1.8rem;
}

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

.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;
}

/* 主页横幅样式 */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 150px 0 100px;
    text-align: center;
    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 1000 100" fill="%23ffffff" opacity="0.1"><polygon points="1000,100 1000,0 0,100"/></svg>') no-repeat bottom;
    background-size: cover;
}

.hero-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    position: relative;
    z-index: 1;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    animation: fadeInUp 1s ease;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 1rem;
    opacity: 0.9;
    animation: fadeInUp 1s ease 0.2s both;
}

.hero-description {
    font-size: 1.1rem;
    margin-bottom: 2rem;
    opacity: 0.8;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
    animation: fadeInUp 1s ease 0.4s both;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    animation: fadeInUp 1s ease 0.6s both;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 50px;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    border: 2px solid transparent;
    cursor: pointer;
    font-size: 1rem;
}

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

.btn-primary:hover {
    background: transparent;
    color: #2c5aa0;
    border-color: #2c5aa0;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(44, 90, 160, 0.3);
}

.btn-secondary {
    background: transparent;
    color: white;
    border-color: white;
}

.btn-secondary:hover {
    background: white;
    color: #2c5aa0;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(255, 255, 255, 0.3);
}

.btn-full {
    width: 100%;
}

/* 通用区块样式 */
.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: #333;
    margin-bottom: 1rem;
    position: relative;
}

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

.section-subtitle {
    font-size: 1.2rem;
    color: #666;
    max-width: 600px;
    margin: 0 auto;
}

/* 关于我们样式 */
.about {
    padding: 100px 0;
    background: #f8f9fa;
}

.about-content {
    max-width: 1000px;
    margin: 0 auto;
}

.about-text h3 {
    font-size: 1.8rem;
    color: #333;
    margin-bottom: 1.5rem;
    text-align: center;
}

.about-text p {
    font-size: 1.1rem;
    line-height: 1.8;
    color: #666;
    margin-bottom: 3rem;
    text-align: center;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.feature {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

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

.feature h4 {
    font-size: 1.3rem;
    color: #333;
    margin-bottom: 1rem;
}

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

/* 服务项目样式 */
.services {
    padding: 100px 0;
    background: white;
}

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

.service-card {
    background: #f8f9fa;
    padding: 2.5rem;
    border-radius: 15px;
    text-align: center;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.service-card:hover {
    background: white;
    border-color: #2c5aa0;
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(44, 90, 160, 0.1);
}

.service-icon {
    font-size: 3.5rem;
    margin-bottom: 1.5rem;
}

.service-card h3 {
    font-size: 1.5rem;
    color: #333;
    margin-bottom: 1rem;
}

.service-card p {
    color: #666;
    line-height: 1.7;
}

/* 联系我们样式 */
.contact {
    padding: 100px 0;
    background: #f8f9fa;
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: start;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    background: white;
    padding: 1.5rem;
    border-radius: 10px;
    box-shadow: 0 3px 15px rgba(0, 0, 0, 0.1);
}

.contact-icon {
    font-size: 1.5rem;
    margin-top: 0.2rem;
}

.contact-details h4 {
    color: #333;
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

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

.contact-form {
    background: white;
    padding: 2.5rem;
    border-radius: 15px;
    box-shadow: 0 5px 25px rgba(0, 0, 0, 0.1);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #e9ecef;
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.3s ease;
    font-family: inherit;
}

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

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

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

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: 1rem;
    color: #ecf0f1;
}

.footer-section p,
.footer-section li {
    color: #bdc3c7;
    line-height: 1.6;
}

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

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

.footer-bottom {
    border-top: 1px solid #34495e;
    padding-top: 20px;
    text-align: center;
    color: #95a5a6;
}

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

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        left: -100%;
        top: 70px;
        flex-direction: column;
        background-color: white;
        width: 100%;
        text-align: center;
        transition: 0.3s;
        box-shadow: 0 10px 27px rgba(0, 0, 0, 0.05);
        padding: 2rem 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-title {
        font-size: 2.5rem;
    }

    .hero-subtitle {
        font-size: 1.2rem;
    }

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

    .btn {
        width: 200px;
    }

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

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

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

    .contact-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

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

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

    .nav-container {
        padding: 0 15px;
    }

    .hero {
        padding: 120px 0 80px;
    }

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

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

    .about,
    .services,
    .contact {
        padding: 60px 0;
    }

    .service-card,
    .contact-form {
        padding: 1.5rem;
    }

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

    .services-grid .service-card {
        min-width: unset;
    }
}

/* 滚动条样式 */
::-webkit-scrollbar {
    width: 8px;
}

::-webkit-scrollbar-track {
    background: #f1f1f1;
}

::-webkit-scrollbar-thumb {
    background: #2c5aa0;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: #1e3d6f;
}

/* 性能优化 */
.lazy-load {
    opacity: 0;
    transition: opacity 0.3s ease;
}

.lazy-load.loaded {
    opacity: 1;
}

/* 减少布局抖动 */
.aspect-ratio-16-9 {
    aspect-ratio: 16 / 9;
}

.aspect-ratio-4-3 {
    aspect-ratio: 4 / 3;
}

/* 优化动画性能 */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}

/* 提升渲染性能 */
.will-change-transform {
    will-change: transform;
}

.will-change-opacity {
    will-change: opacity;
}

/* 字体显示优化 */
@font-face {
    font-display: swap;
}

/* 关键CSS - 首屏内容 */
.critical {
    contain: layout style paint;
}

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

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