:root {
    --primary-color: #1a365d;
    --primary-light: #2c5282;
    --accent-color: #d69e2e;
    --accent-hover: #b7791f;
    --text-dark: #2d3748;
    --text-light: #718096;
    --text-muted: #a0aec0;
    --bg-white: #ffffff;
    --bg-light: #f7fafc;
    --bg-dark: #1a202c;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.12);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.1);
    --shadow-xl: 0 20px 40px rgba(0,0,0,0.15);
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
    --transition: all 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", "PingFang SC", "Hiragino Sans GB", sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-white);
    overflow-x: hidden;
}

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

.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--primary-color);
    color: white;
    padding: 8px;
    z-index: 10000;
    transition: top 0.3s;
}

.skip-link:focus {
    top: 0;
}

/* Top Bar */
.top-bar {
    background: linear-gradient(90deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: white;
    padding: 12px 0;
    font-size: 14px;
}

.top-bar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
}

.top-bar-left, .top-bar-right {
    display: flex;
    align-items: center;
    gap: 15px;
    flex-wrap: wrap;
}

.top-bar a {
    color: white;
    text-decoration: none;
    transition: opacity 0.3s;
    display: flex;
    align-items: center;
    gap: 5px;
}

.top-bar a:hover {
    opacity: 0.8;
}

.divider {
    color: rgba(255,255,255,0.5);
}

.icon {
    fill: currentColor;
    vertical-align: middle;
}

/* Header */
.header {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: var(--bg-white);
    box-shadow: var(--shadow-sm);
    transition: box-shadow 0.3s;
}

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

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

.header-left {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-wrapper {
    display: flex;
    align-items: center;
    gap: 8px;
}

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

.trademark {
    font-size: 10px;
    color: var(--text-muted);
    vertical-align: super;
}

.divider-vertical {
    color: var(--border-color);
    margin: 0 5px;
}

.business-keyword {
    font-size: 16px;
    font-weight: 600;
    color: var(--primary-color);
}

/* Navigation */
.nav-list {
    display: flex;
    list-style: none;
    gap: 5px;
}

.nav-link {
    padding: 8px 15px;
    text-decoration: none;
    color: var(--text-dark);
    border-radius: var(--radius-sm);
    transition: var(--transition);
    font-size: 15px;
    white-space: nowrap;
}

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

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

.bar {
    width: 25px;
    height: 2px;
    background: var(--text-dark);
    transition: var(--transition);
}

.menu-toggle.active .bar:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

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

.menu-toggle.active .bar:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* Hero Section */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    overflow: hidden;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 50%, var(--accent-color) 100%);
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: url('https://trae-api-cn.mchost.guru/api/ide/v1/text_to_image?prompt=professional+modern+website+banner+background+for+German+website+design+company+blue+gold+gradient+abstract+geometric+shapes+minimalist+corporate+style&image_size=landscape_16_9') center/cover;
    opacity: 0.2;
    animation: heroBgShift 20s ease-in-out infinite;
}

@keyframes heroBgShift {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.1); }
}

.hero-particles {
    position: absolute;
    inset: 0;
    overflow: hidden;
}

.hero-particles::before, .hero-particles::after {
    content: '';
    position: absolute;
    border-radius: 50%;
    opacity: 0.1;
    animation: float 15s ease-in-out infinite;
}

.hero-particles::before {
    width: 400px;
    height: 400px;
    background: var(--accent-color);
    top: -100px;
    right: -100px;
}

.hero-particles::after {
    width: 300px;
    height: 300px;
    background: white;
    bottom: -50px;
    left: -50px;
    animation-delay: 7s;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0) rotate(0deg); }
    33% { transform: translate(30px, -30px) rotate(120deg); }
    66% { transform: translate(-20px, 20px) rotate(240deg); }
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    color: white;
    padding: 100px 0;
    max-width: 900px;
    margin: 0 auto;
}

.hero-title {
    font-size: clamp(2rem, 5vw, 3.5rem);
    font-weight: 700;
    line-height: 1.3;
    margin-bottom: 20px;
}

.title-line {
    display: block;
}

.title-line.highlight {
    color: var(--accent-color);
    font-size: 0.9em;
}

.hero-subtitle {
    font-size: clamp(1rem, 2vw, 1.25rem);
    margin-bottom: 30px;
    opacity: 0.9;
}

.hero-keywords {
    display: flex;
    justify-content: center;
    gap: 15px;
    flex-wrap: wrap;
    margin-bottom: 40px;
}

.keyword-tag {
    padding: 8px 20px;
    background: rgba(255,255,255,0.15);
    border: 1px solid rgba(255,255,255,0.3);
    border-radius: 50px;
    backdrop-filter: blur(10px);
    font-size: 15px;
}

.hero-cta {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    padding: 12px 30px;
    border-radius: var(--radius-md);
    text-decoration: none;
    font-size: 16px;
    font-weight: 500;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

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

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

.scroll-indicator {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    animation: scrollBounce 2s ease-in-out infinite;
}

.mouse {
    width: 30px;
    height: 50px;
    border: 2px solid white;
    border-radius: 15px;
    position: relative;
}

.wheel {
    width: 4px;
    height: 10px;
    background: white;
    border-radius: 2px;
    position: absolute;
    top: 10px;
    left: 50%;
    transform: translateX(-50%);
    animation: scrollWheel 2s ease-in-out infinite;
}

@keyframes scrollBounce {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(10px); }
}

@keyframes scrollWheel {
    0% { opacity: 1; transform: translateX(-50%) translateY(0); }
    100% { opacity: 0; transform: translateX(-50%) translateY(15px); }
}

/* Animation Classes */
[data-animate] {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

[data-animate].animate-in {
    opacity: 1;
    transform: translateY(0);
}

[data-animate="fadeInLeft"].animate-in {
    transform: translateX(0);
}

[data-animate="fadeInRight"].animate-in {
    transform: translateX(0);
}

[data-animate="countUp"].animate-in {
    transform: scale(1);
}

/* Services Section */
.services {
    padding: 80px 0;
    background: var(--bg-light);
}

.section-header {
    text-align: center;
    margin-bottom: 50px;
}

.section-tag {
    display: inline-block;
    padding: 6px 15px;
    background: var(--accent-color);
    color: white;
    border-radius: 50px;
    font-size: 13px;
    margin-bottom: 15px;
}

.section-title {
    font-size: clamp(1.5rem, 3vw, 2.25rem);
    color: var(--primary-color);
    margin-bottom: 15px;
}

.section-desc {
    color: var(--text-light);
    font-size: 16px;
    max-width: 600px;
    margin: 0 auto;
}

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

.service-card {
    background: var(--bg-white);
    padding: 40px 30px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--accent-color);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

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

.service-card:hover::before {
    transform: scaleX(1);
}

.service-icon {
    color: var(--primary-color);
    margin-bottom: 20px;
}

.service-title {
    font-size: 1.25rem;
    margin-bottom: 15px;
    color: var(--primary-color);
}

.service-desc {
    color: var(--text-light);
    margin-bottom: 20px;
    line-height: 1.7;
}

.service-features {
    list-style: none;
    margin-bottom: 25px;
}

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

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

.service-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

.service-link:hover {
    color: var(--accent-color);
    gap: 10px;
}

/* Stats Section */
.stats {
    padding: 60px 0;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: white;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 30px;
    text-align: center;
}

.stat-number {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 700;
    color: var(--accent-color);
    margin-bottom: 10px;
}

.stat-label {
    font-size: 1rem;
    opacity: 0.9;
}

/* About Section */
.about {
    padding: 80px 0;
}

.about-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 50px;
    align-items: center;
}

.about-content {
    max-width: 100%;
}

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

.about-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin-top: 30px;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--text-dark);
}

.feature-icon {
    color: var(--accent-color);
    flex-shrink: 0;
}

.about-visual {
    position: relative;
}

.experience-badge {
    width: 150px;
    height: 150px;
    background: linear-gradient(135deg, var(--accent-color) 0%, var(--accent-hover) 100%);
    border-radius: 50%;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: white;
    margin: 0 auto 30px;
    box-shadow: var(--shadow-lg);
}

.badge-number {
    font-size: 3rem;
    font-weight: 700;
}

.badge-text {
    font-size: 0.9rem;
    opacity: 0.9;
}

.timeline {
    position: relative;
    padding-left: 30px;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border-color);
}

.timeline-item {
    position: relative;
    margin-bottom: 30px;
}

.timeline-dot {
    position: absolute;
    left: -35px;
    top: 5px;
    width: 12px;
    height: 12px;
    background: var(--accent-color);
    border-radius: 50%;
    border: 3px solid var(--bg-white);
    box-shadow: 0 0 0 2px var(--accent-color);
}

.timeline-content h4 {
    color: var(--primary-color);
    margin-bottom: 5px;
}

.timeline-content p {
    color: var(--text-light);
    font-size: 0.95rem;
}

/* SEO Section */
.seo-section {
    padding: 80px 0;
    background: var(--bg-light);
}

.seo-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
}

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

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

.seo-icon {
    font-size: 3rem;
    margin-bottom: 15px;
}

.seo-title {
    font-size: 1.1rem;
    margin-bottom: 10px;
    color: var(--primary-color);
}

.seo-desc {
    color: var(--text-light);
    line-height: 1.6;
}

/* FAQ Section */
.faq {
    padding: 80px 0;
}

.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    border-bottom: 1px solid var(--border-color);
}

.faq-question {
    width: 100%;
    padding: 20px 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: none;
    border: none;
    cursor: pointer;
    text-align: left;
    font-size: 1.05rem;
    color: var(--text-dark);
    font-weight: 500;
    transition: var(--transition);
}

.faq-question:hover {
    color: var(--primary-color);
}

.faq-arrow {
    color: var(--text-muted);
    transition: transform 0.3s ease;
    flex-shrink: 0;
    margin-left: 15px;
}

.faq-question[aria-expanded="true"] .faq-arrow {
    transform: rotate(180deg);
    color: var(--accent-color);
}

.faq-question[aria-expanded="true"] {
    color: var(--primary-color);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease, padding 0.3s ease;
}

.faq-answer.expanded {
    max-height: 500px;
    padding-bottom: 20px;
}

.faq-answer p {
    color: var(--text-light);
    line-height: 1.7;
}

/* Contact Section */
.contact {
    padding: 80px 0;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: white;
}

.contact .section-tag {
    background: rgba(255,255,255,0.2);
}

.contact .section-title {
    color: white;
}

.contact .section-desc {
    color: rgba(255,255,255,0.8);
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
}

.contact-card {
    background: rgba(255,255,255,0.1);
    padding: 30px;
    border-radius: var(--radius-lg);
    text-align: center;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255,255,255,0.2);
    transition: var(--transition);
}

.contact-card:hover {
    background: rgba(255,255,255,0.15);
    transform: translateY(-5px);
}

.contact-icon {
    font-size: 2.5rem;
    margin-bottom: 15px;
}

.contact-item-title {
    font-size: 1.1rem;
    margin-bottom: 15px;
}

.contact-info {
    color: rgba(255,255,255,0.9);
    margin-bottom: 5px;
}

.contact-info-link {
    color: var(--accent-color);
    text-decoration: none;
    font-size: 1.1rem;
}

.contact-info-link:hover {
    text-decoration: underline;
}

.wechat-card .contact-icon {
    font-size: 2rem;
}

.wechat-qrcode {
    width: 150px;
    height: 150px;
    object-fit: cover;
    border-radius: var(--radius-md);
    margin: 15px 0;
    background: white;
    padding: 10px;
}

.wechat-hint {
    font-size: 0.9rem;
    opacity: 0.8;
}

/* Friendly Links */
.friendly-links {
    padding: 50px 0;
    background: var(--bg-light);
}

.links-title {
    text-align: center;
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 25px;
    font-weight: 400;
}

.links-grid {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 15px;
}

.links-grid a {
    padding: 8px 15px;
    background: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    text-decoration: none;
    color: var(--text-dark);
    font-size: 14px;
    transition: var(--transition);
}

.links-grid a:hover {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

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

.footer-content {
    text-align: center;
}

.copyright {
    margin-bottom: 10px;
}

.copyright a {
    color: var(--accent-color);
    text-decoration: none;
}

.copyright a:hover {
    text-decoration: underline;
}

.icp a {
    color: var(--text-muted);
    text-decoration: none;
}

.icp a:hover {
    color: white;
    text-decoration: underline;
}

/* Back to Top */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 999;
    display: flex;
    align-items: center;
    justify-content: center;
}

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

.back-to-top:hover {
    background: var(--accent-color);
    transform: translateY(-3px);
}

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

@media (max-width: 768px) {
    .top-bar .container {
        flex-direction: column;
        text-align: center;
    }
    
    .top-bar-left, .top-bar-right {
        justify-content: center;
    }
    
    .header .container {
        flex-wrap: wrap;
    }
    
    .nav {
        width: 100%;
        max-height: 0;
        overflow: hidden;
        transition: max-height 0.3s ease;
    }
    
    .nav.active {
        max-height: 400px;
    }
    
    .nav-list {
        flex-direction: column;
        padding: 15px 0;
    }
    
    .nav-link {
        padding: 12px 20px;
    }
    
    .menu-toggle {
        display: flex;
    }
    
    .services-grid, .stats-grid, .about-grid, .seo-grid, .contact-grid {
        grid-template-columns: 1fr;
    }
    
    .hero-cta {
        flex-direction: column;
        align-items: center;
    }
    
    .btn {
        width: 100%;
        max-width: 300px;
        justify-content: center;
    }
    
    .links-grid {
        gap: 10px;
    }
    
    .links-grid a {
        font-size: 13px;
        padding: 6px 12px;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.75rem;
    }
    
    .section-title {
        font-size: 1.5rem;
    }
    
    .service-card, .seo-card, .contact-card {
        padding: 25px;
    }
    
    .back-to-top {
        bottom: 20px;
        right: 20px;
        width: 45px;
        height: 45px;
    }
}