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

:root {
    --primary-color: #6366f1;
    --secondary-color: #8b5cf6;
    --accent-color: #ec4899;
    --success-color: #10b981;
    --warning-color: #f59e0b;
    --danger-color: #ef4444;
    --dark-color: #1f2937;
    --light-color: #f9fafb;
    --text-color: #374151;
    --text-light: #6b7280;
    --gradient-1: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-2: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-3: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --gradient-4: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
    --gradient-5: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 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);
    --shadow-2xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    --glow-primary: 0 0 20px rgba(99, 102, 241, 0.5);
    --glow-secondary: 0 0 20px rgba(139, 92, 246, 0.5);
}

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-color);
    overflow-x: hidden;
    background: #fff;
}

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

/* 导航栏 - 增强版 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(20px) saturate(180%);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar.scrolled {
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    background: rgba(255, 255, 255, 0.98);
}

.nav-wrapper {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.5rem;
    font-weight: bold;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    transition: all 0.3s ease;
}

.logo:hover {
    transform: scale(1.05);
}

.logo i {
    font-size: 1.8rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    animation: pulse 2s ease-in-out infinite;
}

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

.nav-link {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: all 0.3s ease;
    position: relative;
    padding: 0.5rem 0;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 3px;
    background: var(--gradient-primary);
    transition: width 0.3s ease;
    border-radius: 2px;
}

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

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

.hamburger {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background: var(--dark-color);
    transition: all 0.3s ease;
    border-radius: 2px;
}

/* 首页横幅 - 超级增强版 */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
}

.gradient-bg {
    position: absolute;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, 
        #667eea 0%, 
        #764ba2 25%, 
        #f093fb 50%, 
        #667eea 75%, 
        #764ba2 100%);
    background-size: 400% 400%;
    animation: gradientShift 15s ease infinite;
}

@keyframes gradientShift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.particles {
    position: absolute;
    width: 100%;
    height: 100%;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.2);
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    color: white;
    padding: 2rem;
    max-width: 900px;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1.5rem;
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(10px);
    border-radius: 50px;
    margin-bottom: 2rem;
    border: 1px solid rgba(255, 255, 255, 0.2);
    animation: float 3s ease-in-out infinite;
}

.hero-badge i {
    color: #fbbf24;
    animation: spin 3s linear infinite;
}

@keyframes spin {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

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

.hero-title {
    font-size: 4rem;
    font-weight: 900;
    margin-bottom: 1.5rem;
    text-shadow: 2px 4px 8px rgba(0, 0, 0, 0.3);
    letter-spacing: -1px;
}

.text-gradient {
    background: linear-gradient(135deg, #fff 0%, #f0f0f0 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    display: inline-block;
    animation: shimmer 3s ease-in-out infinite;
}

@keyframes shimmer {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.8; }
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: 2rem;
    font-weight: 300;
    text-shadow: 1px 2px 4px rgba(0, 0, 0, 0.3);
}

.typing-text {
    border-right: 2px solid white;
    animation: typing 3.5s steps(40, end), blink-caret 0.75s step-end infinite;
}

.feature-tags {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 2rem;
}

.tag {
    padding: 0.5rem 1.25rem;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    border-radius: 50px;
    border: 1px solid rgba(255, 255, 255, 0.3);
    font-size: 0.95rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.3s ease;
}

.tag:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.tag i {
    color: #10b981;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 3rem;
}

.btn {
    padding: 1rem 2.5rem;
    border: none;
    border-radius: 50px;
    font-size: 1.1rem;
    font-weight: 600;
    cursor: pointer;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn i {
    position: relative;
    z-index: 1;
}

.btn span {
    position: relative;
    z-index: 1;
}

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

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

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

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

.btn-glow {
    animation: glow 2s ease-in-out infinite;
}

@keyframes glow {
    0%, 100% { box-shadow: 0 0 5px rgba(255, 255, 255, 0.5), 0 0 10px rgba(255, 255, 255, 0.3); }
    50% { box-shadow: 0 0 20px rgba(255, 255, 255, 0.8), 0 0 30px rgba(255, 255, 255, 0.5); }
}

.btn-glass {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.btn-block {
    width: 100%;
    justify-content: center;
}

.hero-stats {
    display: flex;
    gap: 2rem;
    justify-content: center;
    flex-wrap: wrap;
}

.stat-box {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 1.5rem 2rem;
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(10px);
    border-radius: 15px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    transition: all 0.3s ease;
}

.stat-box:hover {
    background: rgba(255, 255, 255, 0.25);
    transform: translateY(-5px);
}

.stat-icon {
    font-size: 2.5rem;
    color: #fbbf24;
}

.stat-content {
    text-align: left;
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    line-height: 1;
    margin-bottom: 0.25rem;
}

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

.scroll-indicator {
    position: absolute;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%);
    color: white;
    text-align: center;
    z-index: 2;
    cursor: pointer;
}

.mouse {
    width: 30px;
    height: 50px;
    border: 2px solid white;
    border-radius: 15px;
    display: flex;
    justify-content: center;
    padding-top: 8px;
    margin: 0 auto 0.5rem;
}

.wheel {
    width: 4px;
    height: 10px;
    background: white;
    border-radius: 2px;
    animation: scroll 1.5s ease-in-out infinite;
}

@keyframes scroll {
    0% { opacity: 1; transform: translateY(0); }
    100% { opacity: 0; transform: translateY(15px); }
}

.scroll-indicator p {
    font-size: 0.85rem;
    opacity: 0.8;
}

/* 通用区块样式 */
section {
    padding: 6rem 0;
    position: relative;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-title {
    font-size: 2.8rem;
    font-weight: 700;
    color: var(--dark-color);
    margin-bottom: 1rem;
    position: relative;
    display: inline-block;
}

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

.title-divider::before,
.title-divider::after {
    content: '';
    position: absolute;
    top: 50%;
    width: 8px;
    height: 8px;
    background: var(--primary-color);
    border-radius: 50%;
    transform: translateY(-50%);
}

.title-divider::before {
    left: -15px;
}

.title-divider::after {
    right: -15px;
}

.section-subtitle {
    font-size: 1.2rem;
    color: var(--text-light);
}

/* 关于我们 */
.about {
    background: var(--light-color);
    position: relative;
    overflow: hidden;
}

.about::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -10%;
    width: 500px;
    height: 500px;
    background: var(--gradient-3);
    opacity: 0.05;
    border-radius: 50%;
}

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

.about-image {
    position: relative;
}

.image-placeholder {
    width: 100%;
    aspect-ratio: 1;
    background: var(--gradient-primary);
    border-radius: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 6rem;
    box-shadow: var(--shadow-2xl);
    position: relative;
    overflow: hidden;
}

.image-placeholder::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: linear-gradient(45deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    animation: shine 3s ease-in-out infinite;
}

@keyframes shine {
    0% { transform: translateX(-100%) translateY(-100%) rotate(45deg); }
    100% { transform: translateX(100%) translateY(100%) rotate(45deg); }
}

.about-text h3 {
    font-size: 2.2rem;
    color: var(--dark-color);
    margin-bottom: 1rem;
}

.highlight-text {
    font-size: 1.3rem;
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.about-text p {
    margin-bottom: 1.5rem;
    line-height: 1.8;
    color: var(--text-color);
    font-size: 1.05rem;
}

.about-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-top: 3rem;
}

.stat-item {
    text-align: center;
    padding: 2rem;
    background: white;
    border-radius: 15px;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
}

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

.stat-number {
    font-size: 3rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    color: var(--text-light);
    margin-top: 0.5rem;
    font-size: 1.05rem;
}

/* 服务项目 */
.services {
    background: white;
    position: relative;
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2.5rem;
}

.service-card {
    background: white;
    padding: 2.5rem;
    border-radius: 20px;
    box-shadow: var(--shadow-md);
    transition: all 0.4s ease;
    border: 2px solid transparent;
    position: relative;
    overflow: hidden;
}

.service-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--gradient-primary);
    opacity: 0;
    transition: opacity 0.4s ease;
    z-index: 0;
}

.service-card:hover::before {
    opacity: 0.05;
}

.service-card:hover {
    transform: translateY(-15px) scale(1.02);
    box-shadow: var(--shadow-2xl);
    border-color: var(--primary-color);
}

.service-icon {
    width: 80px;
    height: 80px;
    background: var(--gradient-primary);
    border-radius: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    color: white;
    font-size: 2.2rem;
    position: relative;
    z-index: 1;
    transition: all 0.3s ease;
}

.service-card:hover .service-icon {
    transform: rotateY(360deg);
    box-shadow: var(--glow-primary);
}

.service-card h3 {
    font-size: 1.6rem;
    color: var(--dark-color);
    margin-bottom: 1rem;
    position: relative;
    z-index: 1;
}

.service-card > p {
    color: var(--text-light);
    margin-bottom: 1.5rem;
    line-height: 1.8;
    position: relative;
    z-index: 1;
}

.service-features {
    list-style: none;
    margin-top: 1.5rem;
    position: relative;
    z-index: 1;
}

.service-features li {
    padding: 0.75rem 0;
    color: var(--text-color);
    position: relative;
    padding-left: 2rem;
    transition: all 0.3s ease;
}

.service-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
    font-size: 1.2rem;
    width: 24px;
    height: 24px;
    background: rgba(99, 102, 241, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.9rem;
}

.service-features li:hover {
    padding-left: 2.5rem;
    color: var(--primary-color);
}

/* 我们的优势 */
.advantages {
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    position: relative;
}

.advantages-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2.5rem;
}

.advantage-card {
    background: white;
    padding: 3rem 2rem;
    border-radius: 20px;
    text-align: center;
    box-shadow: var(--shadow-lg);
    transition: all 0.4s ease;
    position: relative;
    overflow: hidden;
}

.advantage-card::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(99, 102, 241, 0.1) 0%, transparent 70%);
    opacity: 0;
    transition: opacity 0.4s ease;
}

.advantage-card:hover::before {
    opacity: 1;
}

.advantage-card:hover {
    transform: translateY(-10px) scale(1.03);
    box-shadow: var(--shadow-2xl);
}

.advantage-icon {
    width: 100px;
    height: 100px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 2rem;
    color: white;
    font-size: 3rem;
    position: relative;
    z-index: 1;
    transition: all 0.4s ease;
}

.advantage-card:hover .advantage-icon {
    transform: scale(1.1) rotate(360deg);
    box-shadow: var(--glow-primary);
}

.advantage-card h3 {
    font-size: 1.5rem;
    color: var(--dark-color);
    margin-bottom: 1rem;
    position: relative;
    z-index: 1;
}

.advantage-card p {
    color: var(--text-light);
    line-height: 1.8;
    position: relative;
    z-index: 1;
}

/* 联系我们 */
.contact {
    background: white;
}

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

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

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: 1.5rem;
    padding: 1.5rem;
    background: var(--light-color);
    border-radius: 15px;
    transition: all 0.3s ease;
}

.contact-item:hover {
    background: white;
    box-shadow: var(--shadow-lg);
    transform: translateX(5px);
}

.contact-icon {
    width: 60px;
    height: 60px;
    background: var(--gradient-primary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
    flex-shrink: 0;
    box-shadow: var(--shadow-md);
}

.contact-details h4 {
    font-size: 1.2rem;
    color: var(--dark-color);
    margin-bottom: 0.5rem;
}

.contact-details p {
    color: var(--text-light);
    line-height: 1.6;
    font-size: 1.05rem;
}

.contact-form-wrapper {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 3rem;
    border-radius: 20px;
    box-shadow: var(--shadow-2xl);
    position: relative;
    overflow: hidden;
}

.contact-form-wrapper::before {
    content: '';
    position: absolute;
    top: -50%;
    right: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255, 255, 255, 0.1) 0%, transparent 70%);
}

.contact-form {
    position: relative;
    z-index: 1;
}

.contact-form h3 {
    font-size: 2rem;
    color: white;
    margin-bottom: 2rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.form-message {
    padding: 1rem;
    border-radius: 10px;
    margin-bottom: 1rem;
    display: none;
    font-weight: 500;
}

.form-message.success {
    background: rgba(16, 185, 129, 0.2);
    border: 1px solid rgba(16, 185, 129, 0.5);
    color: white;
    display: block;
}

.form-message.error {
    background: rgba(239, 68, 68, 0.2);
    border: 1px solid rgba(239, 68, 68, 0.5);
    color: white;
    display: block;
}

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

.form-group label {
    display: block;
    color: white;
    margin-bottom: 0.5rem;
    font-weight: 500;
    font-size: 0.95rem;
}

.form-group label i {
    margin-right: 0.5rem;
}

.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 1rem 1.25rem;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 10px;
    font-size: 1rem;
    transition: all 0.3s ease;
    font-family: inherit;
    background: rgba(255, 255, 255, 0.95);
    color: var(--dark-color);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: white;
    background: white;
    box-shadow: 0 0 0 3px rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
}

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

.form-group select {
    cursor: pointer;
}

/* 页脚 */
.footer {
    background: var(--dark-color);
    color: white;
    padding: 4rem 0 1.5rem;
    position: relative;
}

.footer::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: var(--gradient-primary);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-section h4 {
    font-size: 1.3rem;
    margin-bottom: 1.5rem;
    color: white;
    position: relative;
    padding-bottom: 0.5rem;
}

.footer-section h4::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 50px;
    height: 2px;
    background: var(--gradient-primary);
}

.footer-section p {
    color: #9ca3af;
    margin-bottom: 1rem;
    line-height: 1.8;
}

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

.footer-section ul li {
    margin-bottom: 0.75rem;
}

.footer-section ul li a {
    color: #9ca3af;
    text-decoration: none;
    transition: all 0.3s ease;
    display: inline-block;
}

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

.footer-section ul li i {
    margin-right: 0.75rem;
    color: var(--primary-color);
}

.social-links {
    display: flex;
    gap: 1rem;
    margin-top: 1.5rem;
}

.social-links a {
    width: 45px;
    height: 45px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    text-decoration: none;
    transition: all 0.3s ease;
    font-size: 1.2rem;
}

.social-links a:hover {
    background: var(--primary-color);
    transform: translateY(-5px) rotate(360deg);
    box-shadow: var(--glow-primary);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 2rem;
    text-align: center;
    color: #9ca3af;
}

/* 返回顶部按钮 */
.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 55px;
    height: 55px;
    background: var(--gradient-primary);
    color: white;
    border: none;
    border-radius: 50%;
    font-size: 1.3rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    z-index: 999;
    box-shadow: var(--shadow-xl);
}

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

.back-to-top:hover {
    transform: translateY(-5px) scale(1.1);
    box-shadow: var(--glow-primary);
}

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

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

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: -100%;
        width: 100%;
        height: calc(100vh - 70px);
        background: white;
        flex-direction: column;
        padding: 2rem;
        gap: 1rem;
        transition: left 0.3s ease;
        box-shadow: var(--shadow-lg);
    }

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

    .hamburger {
        display: flex;
    }

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

    .hamburger.active span:nth-child(2) {
        opacity: 0;
    }

    .hamburger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

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

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

    .hero-stats {
        gap: 1rem;
    }

    .stat-box {
        padding: 1rem 1.5rem;
    }

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

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

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

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

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

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

    .contact-form-wrapper {
        padding: 2rem;
    }

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

    .hero-buttons {
        flex-direction: column;
        width: 100%;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

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

    .stat-box {
        flex-direction: column;
        text-align: center;
    }
}

/* 打印样式 */
@media print {
    .navbar,
    .hero-buttons,
    .contact-form-wrapper,
    .back-to-top,
    .scroll-indicator {
        display: none;
    }
}