/* 全局样式 */
:root {
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --secondary-color: #64748b;
    --accent-color: #0ea5e9;
    --text-dark: #1e293b;
    --text-light: #64748b;
    --bg-light: #f8fafc;
    --bg-white: #ffffff;
    --border-color: #e2e8f0;
    --success-color: #10b981;
    --gradient-1: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-2: linear-gradient(135deg, #2563eb 0%, #0ea5e9 100%);
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, 'Noto Sans', sans-serif, 'Apple Color Emoji', 'Segoe UI Emoji', 'Segoe UI Symbol', 'Noto Sans CJK SC';
    color: var(--text-dark);
    line-height: 1.6;
    overflow-x: hidden;
}

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

/* 导航栏 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: all 0.3s ease;
}

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

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.nav-brand i {
    font-size: 1.8rem;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 2rem;
}

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

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

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

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

.lang-switch {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    background: var(--gradient-2);
    color: white;
    border: none;
    border-radius: 20px;
    cursor: pointer;
    font-weight: 500;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.lang-switch:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.mobile-menu-toggle {
    display: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--primary-color);
}

/* 主页横幅 */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--gradient-1);
    color: white;
    text-align: center;
    padding-top: 80px;
    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 1440 320"><path fill="%23ffffff" fill-opacity="0.1" d="M0,96L48,112C96,128,192,160,288,160C384,160,480,128,576,122.7C672,117,768,139,864,138.7C960,139,1056,117,1152,101.3C1248,85,1344,75,1392,69.3L1440,64L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>');
    background-size: cover;
    background-position: bottom;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.2);
}

.hero-content {
    position: relative;
    z-index: 10;
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    animation: fadeInUp 1s ease;
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    opacity: 0.9;
    animation: fadeInUp 1s ease 0.2s backwards;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    animation: fadeInUp 1s ease 0.4s backwards;
}

.scroll-indicator {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    font-size: 2rem;
    animation: bounce 2s infinite;
}

/* 按钮样式 */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    border-radius: 30px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

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

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

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

.btn-secondary:hover {
    background: white;
    color: var(--primary-color);
    transform: translateY(-3px);
}

/* 区块通用样式 */
section {
    padding: 5rem 0;
}

.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

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

.title-underline {
    width: 80px;
    height: 4px;
    background: var(--gradient-2);
    margin: 0 auto 1rem;
    border-radius: 2px;
}

.section-description {
    font-size: 1.125rem;
    color: var(--text-light);
    max-width: 600px;
    margin: 0 auto;
}

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

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

.about-text h3 {
    font-size: 2rem;
    color: var(--text-dark);
    margin-bottom: 1rem;
}

.about-text p {
    color: var(--text-light);
    font-size: 1.125rem;
    line-height: 1.8;
    margin-bottom: 2rem;
}

.about-features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-dark);
    font-weight: 500;
}

.feature-item i {
    color: var(--success-color);
    font-size: 1.25rem;
}

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

.image-placeholder {
    width: 100%;
    height: 400px;
    background: var(--gradient-2);
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-xl);
}

.image-placeholder i {
    font-size: 8rem;
    color: rgba(255, 255, 255, 0.5);
}

/* 服务项目 */
.services {
    background: var(--bg-light);
}

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

.service-card {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
}

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

.service-icon {
    width: 70px;
    height: 70px;
    background: var(--gradient-2);
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
}

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

.service-card h3 {
    font-size: 1.5rem;
    color: var(--text-dark);
    margin-bottom: 1rem;
}

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

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

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

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.info-card {
    display: flex;
    gap: 1.5rem;
    padding: 1.5rem;
    background: var(--bg-light);
    border-radius: 10px;
    transition: all 0.3s ease;
}

.info-card:hover {
    background: white;
    box-shadow: var(--shadow-md);
}

.info-icon {
    width: 50px;
    height: 50px;
    background: var(--gradient-2);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.info-icon i {
    font-size: 1.5rem;
    color: white;
}

.info-text h4 {
    font-size: 1.125rem;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.info-text p {
    color: var(--text-light);
    line-height: 1.6;
}

.info-text a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.3s ease;
}

.info-text a:hover {
    color: var(--primary-dark);
}

/* 联系表单 */
.contact-form-container {
    background: var(--bg-light);
    padding: 2rem;
    border-radius: 15px;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.form-group {
    position: relative;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    font-size: 1rem;
    font-family: inherit;
    transition: all 0.3s ease;
    background: white;
}

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

.form-group input:focus + label,
.form-group input:not(:placeholder-shown) + label,
.form-group textarea:focus + label,
.form-group textarea:not(:placeholder-shown) + label {
    top: -10px;
    left: 10px;
    font-size: 0.875rem;
    background: white;
    padding: 0 0.5rem;
    color: var(--primary-color);
}

.form-group label {
    position: absolute;
    left: 1rem;
    top: 1rem;
    color: var(--text-light);
    transition: all 0.3s ease;
    pointer-events: none;
}

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

.contact-form .btn {
    width: 100%;
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

/* 页脚 */
.footer {
    background: var(--text-dark);
    color: white;
    padding: 3rem 0 1rem;
}

.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: 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: 0.5rem;
}

.footer-section ul li a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.footer-section ul li i {
    margin-right: 0.5rem;
    color: var(--accent-color);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: rgba(255, 255, 255, 0.6);
}

.footer-links {
    margin-top: 1rem;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
}

.footer-links a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

.footer-links .separator {
    color: rgba(255, 255, 255, 0.3);
}

/* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 50px;
    height: 50px;
    background: var(--gradient-2);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    box-shadow: var(--shadow-lg);
    transition: all 0.3s ease;
    z-index: 999;
}

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

.back-to-top.show {
    display: flex;
}

/* 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) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: white;
        flex-direction: column;
        padding: 2rem;
        transition: left 0.3s ease;
        box-shadow: var(--shadow-lg);
    }

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

    .mobile-menu-toggle {
        display: block;
    }

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

    .hero-subtitle {
        font-size: 1.125rem;
    }

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

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

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

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

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

    .footer-links {
        flex-direction: column;
        gap: 0.5rem;
    }

    .footer-links .separator {
        display: none;
    }
}

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

    .hero-title {
        font-size: 1.75rem;
    }

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

    .btn {
        padding: 0.75rem 1.5rem;
        font-size: 0.875rem;
    }

    .contact-form-container {
        padding: 1.5rem;
    }
}