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

:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary-color: #0ea5e9;
    --text-dark: #1e293b;
    --text-light: #64748b;
    --bg-light: #f8fafc;
    --bg-white: #ffffff;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --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-dark);
    overflow-x: hidden;
}

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

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: var(--bg-white);
    box-shadow: var(--shadow);
    z-index: 1000;
    transition: var(--transition);
}

.header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.logo img {
    height: 40px;
    width: auto;
}

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

.nav-link {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 500;
    padding: 8px 0;
    position: relative;
    transition: var(--transition);
}

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

.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%;
}

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

.menu-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    transition: var(--transition);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    position: relative;
    padding: 120px 20px 80px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.hero-bg {
    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="M0,96L48,112C96,128,192,160,288,160C384,160,480,128,576,122.7C672,117,768,139,864,154.7C960,171,1056,181,1152,165.3C1248,149,1344,107,1392,85.3L1440,64L1440,320L1392,320C1344,320,1248,320,1152,320C1056,320,960,320,864,320C768,320,672,320,576,320C480,320,384,320,288,320C192,320,96,320,48,320L0,320Z"></path></svg>') no-repeat bottom;
    background-size: cover;
}

.hero-content {
    position: relative;
    z-index: 1;
    max-width: 1000px;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 800;
    margin-bottom: 20px;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 40px;
    opacity: 0.9;
}

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

.btn {
    padding: 14px 32px;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    border: none;
}

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

.btn-primary:hover {
    background: var(--bg-light);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-outline {
    background: transparent;
    color: white;
    border: 2px solid white;
}

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

.btn-block {
    width: 100%;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 60px;
    margin-top: 60px;
    position: relative;
    z-index: 1;
    flex-wrap: wrap;
}

.stat-item {
    text-align: center;
}

.stat-number {
    font-size: 3rem;
    font-weight: 800;
    display: block;
}

.stat-label {
    font-size: 0.9rem;
    opacity: 0.9;
    display: block;
    margin-top: 5px;
}

/* Section Styles */
section {
    padding: 80px 0;
}

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

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-bottom: 15px;
}

.section-subtitle {
    font-size: 1.1rem;
    color: var(--text-light);
}

/* About Section */
.about {
    background: var(--bg-white);
}

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

.about-text p {
    color: var(--text-light);
    margin-bottom: 20px;
    line-height: 1.8;
}

.about-features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-top: 30px;
}

.feature-item {
    display: flex;
    align-items: flex-start;
    gap: 15px;
}

.feature-icon {
    width: 40px;
    height: 40px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    flex-shrink: 0;
}

.feature-text h4 {
    font-size: 1rem;
    margin-bottom: 5px;
}

.feature-text p {
    font-size: 0.9rem;
    margin: 0;
}

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

.image-placeholder {
    width: 100%;
    max-width: 400px;
    height: 400px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: var(--shadow-lg);
}

.image-content {
    text-align: center;
    color: white;
}

.image-icon {
    font-size: 5rem;
    margin-bottom: 20px;
}

.image-content p {
    font-size: 1.2rem;
    font-weight: 600;
}

/* Services Section */
.services {
    background: var(--bg-light);
}

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

.service-card {
    background: var(--bg-white);
    padding: 40px 30px;
    border-radius: 16px;
    box-shadow: var(--shadow);
    transition: var(--transition);
    text-align: center;
}

.service-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-lg);
}

.service-icon {
    font-size: 3rem;
    margin-bottom: 20px;
}

.service-card h3 {
    font-size: 1.4rem;
    margin-bottom: 15px;
    color: var(--text-dark);
}

.service-card > p {
    color: var(--text-light);
    margin-bottom: 20px;
}

.service-list {
    list-style: none;
    text-align: left;
}

.service-list li {
    padding: 8px 0;
    color: var(--text-light);
    position: relative;
    padding-left: 20px;
}

.service-list li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* Cases Section */
.cases {
    background: var(--bg-white);
}

.cases-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.case-card {
    background: var(--bg-white);
    border-radius: 16px;
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.case-image {
    height: 200px;
    overflow: hidden;
}

.case-placeholder {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 4rem;
    color: white;
}

.case-content {
    padding: 25px;
}

.case-tag {
    display: inline-block;
    background: var(--primary-color);
    color: white;
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    margin-bottom: 15px;
}

.case-content h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
}

.case-content > p {
    color: var(--text-light);
    margin-bottom: 15px;
}

.case-stats {
    display: flex;
    gap: 20px;
    padding-top: 15px;
    border-top: 1px solid var(--border-color);
}

.case-stats span {
    font-size: 0.9rem;
    color: var(--text-light);
}

.case-stats strong {
    color: var(--primary-color);
}

/* Contact Section */
.contact {
    background: var(--bg-light);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
}

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

.info-item {
    display: flex;
    align-items: flex-start;
    gap: 20px;
}

.info-icon {
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    flex-shrink: 0;
}

.info-text h4 {
    font-size: 1.1rem;
    margin-bottom: 8px;
}

.info-text p {
    color: var(--text-light);
    margin: 5px 0;
}

.contact-form {
    background: var(--bg-white);
    padding: 40px;
    border-radius: 16px;
    box-shadow: var(--shadow);
}

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

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 14px 18px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 1rem;
    transition: var(--transition);
    font-family: inherit;
}

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

.form-group textarea {
    resize: vertical;
}

/* Footer */
.footer {
    background: var(--text-dark);
    color: white;
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1.5fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 15px;
}

.footer-logo img {
    height: 40px;
}

.footer-desc {
    color: #94a3b8;
    margin-bottom: 20px;
    line-height: 1.6;
}

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

.social-link {
    width: 40px;
    height: 40px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    font-size: 1.2rem;
    transition: var(--transition);
}

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

.footer-section h4 {
    font-size: 1.1rem;
    margin-bottom: 20px;
}

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

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

.footer-section ul li a {
    color: #94a3b8;
    text-decoration: none;
    transition: var(--transition);
}

.footer-section ul li a:hover {
    color: white;
    padding-left: 5px;
}

.footer-contact li {
    color: #94a3b8;
    margin-bottom: 12px;
    line-height: 1.5;
}

.footer-bottom {
    text-align: center;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: #94a3b8;
}

.footer-bottom a {
    color: #94a3b8;
    text-decoration: none;
}

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

/* Back to Top */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 999;
    box-shadow: var(--shadow-lg);
}

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

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

/* Responsive */
@media (max-width: 1024px) {
    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-content {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    .menu-toggle {
        display: flex;
    }
    
    .nav {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--bg-white);
        box-shadow: var(--shadow);
        padding: 20px;
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }
    
    .nav.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-list {
        flex-direction: column;
        gap: 15px;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-stats {
        gap: 30px;
    }
    
    .about-content {
        grid-template-columns: 1fr;
    }
    
    .about-image {
        order: -1;
    }
    
    .image-placeholder {
        height: 300px;
    }
    
    .services-grid {
        grid-template-columns: 1fr;
    }
    
    .cases-grid {
        grid-template-columns: 1fr;
    }
    
    .contact-content {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
    
    .section-title {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 250px;
    }
    
    .hero-stats {
        gap: 20px;
    }
    
    .stat-number {
        font-size: 2rem;
    }
    
    .about-features {
        grid-template-columns: 1fr;
    }
    
    .contact-form {
        padding: 25px;
    }
}

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

.animate {
    animation: fadeInUp 0.6s ease forwards;
}

.animate-delay-1 {
    animation-delay: 0.1s;
}

.animate-delay-2 {
    animation-delay: 0.2s;
}

.animate-delay-3 {
    animation-delay: 0.3s;
}

.animate-delay-4 {
    animation-delay: 0.4s;
}