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

:root {
    /* 主色调 */
    --primary-color: #667eea;
    --primary-dark: #5568d3;
    --primary-light: #8b9eef;

    /* 辅助色 */
    --secondary-color: #764ba2;
    --accent-color: #f093fb;

    /* 中性色 */
    --text-dark: #1a1a1a;
    --text-gray: #666;
    --text-light: #999;
    --bg-light: #f8f9fa;
    --bg-white: #ffffff;
    --border-color: #e0e0e0;

    /* 渐变色 */
    --gradient-primary: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --gradient-accent: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --gradient-dark: linear-gradient(135deg, #1a1a1a 0%, #2d2d2d 100%);

    /* 阴影 */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.12);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.16);

    /* 间距 */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;

    /* 圆角 */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
    --radius-xl: 24px;
}

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB',
        'Microsoft YaHei', 'Helvetica Neue', Helvetica, Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    background-color: var(--bg-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

ul {
    list-style: none;
}

/* 容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-sm);
}

/* ===================================
   导航栏
   =================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.98);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: all 0.3s ease;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem var(--spacing-sm);
}

.nav-brand h1 {
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.nav-menu a {
    font-weight: 500;
    color: var(--text-dark);
    position: relative;
    padding: 0.5rem 0;
}

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

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

.nav-menu a.active {
    color: var(--primary-color);
}

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

.hamburger span {
    width: 24px;
    height: 2px;
    background: var(--text-dark);
    transition: all 0.3s ease;
}

/* ===================================
   按钮样式
   =================================== */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    font-size: 1rem;
    font-weight: 600;
    text-align: center;
    border: none;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.3s ease;
}

.btn-primary {
    background: var(--gradient-primary);
    color: white;
    box-shadow: var(--shadow-md);
}

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

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

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

/* ===================================
   页面头部
   =================================== */
.page-header {
    margin-top: 80px;
    padding: var(--spacing-xl) 0;
    background: var(--gradient-primary);
    color: white;
    text-align: center;
}

.page-header h1 {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.page-header p {
    font-size: 1.25rem;
    opacity: 0.9;
}

/* ===================================
   章节通用样式
   =================================== */
section {
    padding: var(--spacing-xl) 0;
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.section-header h2 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
}

.section-header p {
    font-size: 1.125rem;
    color: var(--text-gray);
}

/* ===================================
   Hero 区域
   =================================== */
.hero {
    position: relative;
    height: 100vh;
    min-height: 600px;
    background: var(--gradient-primary);
    display: flex;
    align-items: center;
    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 1200 600"><circle cx="100" cy="100" r="80" fill="rgba(255,255,255,0.1)"/><circle cx="1100" cy="500" r="120" fill="rgba(255,255,255,0.1)"/><circle cx="600" cy="300" r="150" fill="rgba(255,255,255,0.05)"/></svg>');
}

.hero-content {
    position: relative;
    z-index: 1;
    color: white;
}

.hero-title {
    font-size: 4rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
}

.hero-subtitle {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-lg);
    opacity: 0.95;
}

.hero-buttons {
    display: flex;
    gap: var(--spacing-sm);
}

/* ===================================
   服务概览
   =================================== */
.services-preview {
    background: var(--bg-light);
}

.services-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

.service-card {
    background: white;
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
    text-align: center;
}

.service-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.service-icon {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-sm);
    background: var(--gradient-primary);
    border-radius: var(--radius-lg);
    color: white;
}

.service-card h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

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

/* ===================================
   数据统计
   =================================== */
.stats {
    background: var(--gradient-dark);
    color: white;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-lg);
    text-align: center;
}

.stat-item {
    padding: var(--spacing-md);
}

.stat-number {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: var(--spacing-xs);
    background: var(--gradient-accent);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.stat-label {
    font-size: 1.125rem;
    opacity: 0.9;
}

/* ===================================
   为什么选择我们
   =================================== */
.why-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

.why-item {
    text-align: center;
    padding: var(--spacing-md);
}

.why-number {
    width: 60px;
    height: 60px;
    margin: 0 auto var(--spacing-sm);
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.5rem;
    font-weight: 700;
}

.why-item h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

.why-item p {
    color: var(--text-gray);
    line-height: 1.8;
}

/* ===================================
   CTA 区域
   =================================== */
.cta {
    background: var(--gradient-primary);
    color: white;
    text-align: center;
}

.cta h2 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
}

.cta p {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-md);
    opacity: 0.95;
}

/* ===================================
   关于我们页面
   =================================== */
.about-intro {
    background: var(--bg-light);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
    align-items: center;
}

.about-text h2 {
    font-size: 2rem;
    margin-bottom: var(--spacing-md);
}

.about-text p {
    margin-bottom: var(--spacing-sm);
    line-height: 1.8;
    color: var(--text-gray);
}

.about-image {
    position: relative;
}

.placeholder-image {
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

/* 企业文化 */
.culture {
    background: var(--bg-light);
}

.culture-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-md);
}

.culture-item {
    background: white;
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    text-align: center;
    transition: all 0.3s ease;
}

.culture-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.culture-icon {
    font-size: 3rem;
    margin-bottom: var(--spacing-sm);
}

.culture-item h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

.culture-item p {
    color: var(--text-gray);
    line-height: 1.8;
}

/* 团队 */
.team-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

.team-member {
    text-align: center;
    padding: var(--spacing-md);
    background: var(--bg-light);
    border-radius: var(--radius-lg);
    transition: all 0.3s ease;
}

.team-member:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.member-avatar {
    width: 150px;
    height: 150px;
    margin: 0 auto var(--spacing-sm);
    border-radius: 50%;
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.team-member h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-xs);
}

.member-title {
    color: var(--primary-color);
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

.team-member p {
    color: var(--text-gray);
    line-height: 1.6;
}

/* 时间线 */
.timeline-section {
    background: var(--bg-light);
}

.timeline {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
    width: 2px;
    height: 100%;
    background: var(--primary-color);
}

.timeline-item {
    display: flex;
    align-items: center;
    margin-bottom: var(--spacing-lg);
    position: relative;
}

.timeline-item:nth-child(odd) {
    flex-direction: row-reverse;
}

.timeline-year {
    width: 80px;
    height: 80px;
    background: var(--gradient-primary);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    font-weight: 700;
    flex-shrink: 0;
    z-index: 1;
}

.timeline-content {
    background: white;
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    margin: 0 var(--spacing-md);
    flex: 1;
}

.timeline-content h3 {
    margin-bottom: var(--spacing-xs);
}

/* ===================================
   服务页面
   =================================== */
.service-detail {
    padding: var(--spacing-xl) 0;
}

.service-detail.alt-bg {
    background: var(--bg-light);
}

.service-detail-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.service-detail-icon {
    width: 100px;
    height: 100px;
    background: var(--gradient-primary);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    flex-shrink: 0;
}

.service-detail-header h2 {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-xs);
}

.service-items {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-md);
}

.service-item-card {
    background: white;
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
}

.service-item-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.service-item-card h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

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

/* 服务流程 */
.process {
    background: var(--bg-light);
}

.process-steps {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-lg);
}

.process-step {
    text-align: center;
    position: relative;
}

.step-number {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-md);
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 2rem;
    font-weight: 700;
}

.process-step h3 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
}

.process-step p {
    color: var(--text-gray);
    line-height: 1.8;
}

/* ===================================
   案例展示页面
   =================================== */
.portfolio-filter {
    padding: var(--spacing-md) 0;
    background: var(--bg-light);
}

.filter-buttons {
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.filter-btn {
    padding: 0.75rem 1.5rem;
    background: white;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
}

.filter-btn:hover,
.filter-btn.active {
    background: var(--gradient-primary);
    color: white;
    border-color: transparent;
}

.portfolio-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: var(--spacing-md);
}

.portfolio-item {
    background: white;
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
}

.portfolio-item:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.portfolio-image {
    width: 100%;
    height: 250px;
    overflow: hidden;
}

.portfolio-image svg {
    width: 100%;
    height: 100%;
    transition: transform 0.3s ease;
}

.portfolio-item:hover .portfolio-image svg {
    transform: scale(1.1);
}

.portfolio-content {
    padding: var(--spacing-md);
}

.portfolio-tag {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: var(--gradient-primary);
    color: white;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: var(--spacing-sm);
}

.portfolio-content h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
}

.portfolio-content > p {
    color: var(--text-gray);
    line-height: 1.6;
    margin-bottom: var(--spacing-md);
}

.portfolio-stats {
    display: flex;
    gap: var(--spacing-md);
    border-top: 1px solid var(--border-color);
    padding-top: var(--spacing-sm);
}

.stat {
    flex: 1;
    text-align: center;
}

.stat-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-gray);
}

/* 客户评价 */
.testimonials {
    background: var(--bg-light);
}

.testimonials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-md);
}

.testimonial-item {
    background: white;
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.testimonial-text {
    font-size: 1.125rem;
    line-height: 1.8;
    color: var(--text-gray);
    margin-bottom: var(--spacing-md);
    font-style: italic;
}

.testimonial-author strong {
    display: block;
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xs);
}

.testimonial-author span {
    color: var(--text-light);
    font-size: 0.875rem;
}

/* ===================================
   联系我们页面
   =================================== */
.contact {
    background: var(--bg-light);
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-lg);
}

.contact-form-section,
.contact-info-section {
    background: white;
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.contact-form-section h2,
.contact-info-section h2 {
    font-size: 2rem;
    margin-bottom: var(--spacing-sm);
}

.contact-form-section > p,
.contact-info-section > p {
    color: var(--text-gray);
    margin-bottom: var(--spacing-md);
}

/* 表单样式 */
.contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.form-group label {
    font-weight: 600;
    color: var(--text-dark);
}

.form-group input,
.form-group select,
.form-group textarea {
    padding: 0.875rem;
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    font-size: 1rem;
    font-family: inherit;
    transition: all 0.3s ease;
}

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

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

/* 联系信息 */
.contact-info-items {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.contact-info-item {
    display: flex;
    gap: var(--spacing-sm);
}

.contact-icon {
    width: 48px;
    height: 48px;
    background: var(--gradient-primary);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    flex-shrink: 0;
}

.contact-info-item h3 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xs);
}

.contact-info-item p {
    color: var(--text-gray);
}

/* 社交媒体 */
.social-section {
    padding-top: var(--spacing-md);
    border-top: 1px solid var(--border-color);
}

.social-section h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-xs);
}

.social-section > p {
    color: var(--text-gray);
    margin-bottom: var(--spacing-sm);
}

.social-links-large {
    display: flex;
    gap: var(--spacing-sm);
}

.social-link {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    transition: all 0.3s ease;
}

.social-link:hover {
    border-color: var(--primary-color);
    background: var(--primary-color);
    color: white;
}

/* 地图 */
.map-section {
    padding: var(--spacing-xl) 0;
}

.map-section h2 {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.map-placeholder {
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

/* 常见问题 */
.faq {
    background: var(--bg-light);
}

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

.faq-item {
    background: white;
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    margin-bottom: var(--spacing-sm);
    box-shadow: var(--shadow-sm);
}

.faq-item h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
}

.faq-item p {
    color: var(--text-gray);
    line-height: 1.8;
}

/* ===================================
   页脚
   =================================== */
.footer {
    background: var(--text-dark);
    color: white;
    padding: var(--spacing-lg) 0 var(--spacing-md);
}

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

.footer-item h3,
.footer-item h4 {
    margin-bottom: var(--spacing-sm);
}

.footer-item p {
    color: rgba(255, 255, 255, 0.7);
    line-height: 1.8;
}

.footer-item ul li {
    margin-bottom: var(--spacing-xs);
}

.footer-item ul li a {
    color: rgba(255, 255, 255, 0.7);
}

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

.social-links {
    display: flex;
    gap: var(--spacing-sm);
}

.social-links a {
    padding: 0.5rem 1rem;
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-sm);
    transition: all 0.3s ease;
}

.social-links a:hover {
    background: var(--primary-color);
}

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-md);
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-bottom p {
    color: rgba(255, 255, 255, 0.5);
}

/* ===================================
   响应式设计
   =================================== */
@media (max-width: 992px) {
    .hero-title {
        font-size: 3rem;
    }

    .page-header h1 {
        font-size: 2rem;
    }

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

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

    .timeline::before {
        left: 20px;
    }

    .timeline-item {
        flex-direction: column !important;
        padding-left: 60px;
    }

    .timeline-year {
        position: absolute;
        left: 0;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 0;
        left: -100%;
        width: 80%;
        max-width: 300px;
        height: 100vh;
        background: white;
        flex-direction: column;
        gap: 0;
        padding: var(--spacing-md);
        box-shadow: var(--shadow-lg);
        transition: left 0.3s ease;
    }

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

    .nav-menu a {
        padding: var(--spacing-sm);
        border-bottom: 1px solid var(--border-color);
    }

    .hamburger {
        display: flex;
    }

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

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

    .hero-buttons {
        flex-direction: column;
    }

    .section-header h2 {
        font-size: 2rem;
    }

    .services-grid,
    .portfolio-grid,
    .why-grid,
    .team-grid,
    .process-steps {
        grid-template-columns: 1fr;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.75rem;
    }

    .page-header {
        padding: var(--spacing-lg) 0;
    }

    .page-header h1 {
        font-size: 1.75rem;
    }

    section {
        padding: var(--spacing-lg) 0;
    }

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

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

.fade-in-up {
    animation: fadeInUp 0.6s ease-out;
}

/* ===================================
   实用类
   =================================== */
.text-center {
    text-align: center;
}

.text-gradient {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.bg-light {
    background: var(--bg-light);
}