/* ==========================================
   CSS Variables - 主题色彩配置
   ========================================== */
:root {
    /* 主色调 - 粉红色 */
    --primary-color: #ff2449;
    --primary-dark: #e01f3f;
    --primary-light: #ff5573;
    
    /* 辅助色 */
    --secondary-color: #000000;
    --accent-color: #ff2449;
    
    /* 背景色 - 浅色主题 */
    --bg-dark: #ffffff;
    --bg-darker: #fafafa;
    --bg-card: #ffffff;
    --bg-card-hover: #f5f5f5;
    
    /* 文字色 - 浅色主题 */
    --text-primary: #000000;
    --text-secondary: #333333;
    --text-muted: #666666;
    
    /* 渐变色 */
    --gradient-primary: linear-gradient(135deg, #ff2449 0%, #ff5573 100%);
    --gradient-secondary: linear-gradient(135deg, #ff2449 0%, #e01f3f 100%);
    --gradient-card: linear-gradient(135deg, rgba(255, 255, 255, 0.95) 0%, rgba(250, 250, 250, 0.95) 100%);
    
    /* 边框与阴影 */
    --border-radius: 12px;
    --border-radius-lg: 16px;
    --box-shadow: 0 8px 32px rgba(0, 0, 0, 0.08);
    --box-shadow-hover: 0 12px 48px rgba(255, 36, 73, 0.15);
    
    /* 间距 */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 4rem;
    --spacing-xl: 6rem;
    
    /* 字体 */
    --font-primary: 'Noto Sans SC', sans-serif;
    --font-heading: 'Poppins', 'Noto Sans SC', sans-serif;
    
    /* 过渡动画 */
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

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

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

body {
    font-family: var(--font-primary);
    background-color: var(--bg-dark);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

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

/* ==========================================
   导航栏
   ========================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.08);
    z-index: 1000;
    transition: var(--transition);
}

.navbar.scrolled {
    box-shadow: 0 4px 24px rgba(0, 0, 0, 0.08);
    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: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    font-family: var(--font-heading);
}

.logo-img {
    height: 2rem;
    width: auto;
    display: block;
}

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

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient-primary);
    transition: var(--transition);
}

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

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

.nav-link.cta-link {
    background: var(--gradient-primary);
    color: var(--text-primary);
    padding: 0.5rem 1.5rem;
    border-radius: 50px;
    font-weight: 600;
}

.nav-link.cta-link::after {
    display: none;
}

.nav-link.cta-link:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(255, 36, 73, 0.4);
}

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

.menu-toggle span {
    width: 25px;
    height: 3px;
    background: var(--primary-color);
    border-radius: 2px;
    transition: var(--transition);
}

/* ==========================================
   Hero区域
   ========================================== */
.hero {
    position: relative;
    min-height: auto;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    margin-top: 70px;
    padding: var(--spacing-lg) 0;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 50% 50%, rgba(255, 36, 73, 0.05) 0%, transparent 50%);
    z-index: 0;
}

.hero-grid {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 30%;
    background-image: 
        linear-gradient(0deg, transparent 24%, rgba(255, 36, 73, 0.1) 25%, rgba(255, 36, 73, 0.1) 26%, transparent 27%, transparent 74%, rgba(255, 36, 73, 0.1) 75%, rgba(255, 36, 73, 0.1) 76%, transparent 77%, transparent),
        linear-gradient(90deg, transparent 24%, rgba(255, 36, 73, 0.1) 25%, rgba(255, 36, 73, 0.1) 26%, transparent 27%, transparent 74%, rgba(255, 36, 73, 0.1) 75%, rgba(255, 36, 73, 0.1) 76%, transparent 77%, transparent);
    background-size: 50px 50px;
    transform: perspective(500px) rotateX(60deg);
    transform-origin: bottom;
    opacity: 0.3;
    pointer-events: none;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    max-width: 900px;
    padding: var(--spacing-sm);
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(255, 36, 73, 0.1);
    border: 1px solid rgba(255, 36, 73, 0.3);
    padding: 0.4rem 1.2rem;
    border-radius: 50px;
    color: var(--primary-color);
    font-weight: 500;
    font-size: 0.9rem;
    margin-bottom: var(--spacing-sm);
    animation: fadeInDown 0.6s ease-out;
}

.hero-title {
    font-size: 3rem;
    font-weight: 900;
    font-family: var(--font-heading);
    margin-bottom: var(--spacing-sm);
    line-height: 1.2;
    animation: fadeInUp 0.6s ease-out 0.2s both;
}

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

.hero-subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
    animation: fadeInUp 0.6s ease-out 0.4s both;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    animation: fadeInUp 0.6s ease-out 0.6s both;
}

.stat-item {
    background: var(--gradient-card);
    border: 1px solid rgba(0, 0, 0, 0.12);
    border-radius: var(--border-radius);
    padding: var(--spacing-sm) var(--spacing-md);
    transition: var(--transition);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

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

.stat-number {
    font-size: 2rem;
    font-weight: 800;
    font-family: var(--font-heading);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 0.25rem;
}

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

.hero-cta {
    display: flex;
    gap: var(--spacing-sm);
    justify-content: center;
    animation: fadeInUp 0.6s ease-out 0.8s both;
}

/* ==========================================
   按钮样式
   ========================================== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.75rem;
    border-radius: 50px;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition);
    border: none;
    cursor: pointer;
    font-size: 0.95rem;
    font-family: var(--font-primary);
}

.btn-primary {
    background: var(--gradient-primary);
    color: var(--text-primary);
    box-shadow: 0 4px 16px rgba(255, 36, 73, 0.3);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 32px rgba(255, 36, 73, 0.5);
}

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

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

.btn-large {
    padding: 1.25rem 2.5rem;
    font-size: 1.125rem;
}

/* ==========================================
   Section通用样式
   ========================================== */
.section-header {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.section-title {
    font-size: 3rem;
    font-weight: 800;
    font-family: var(--font-heading);
    margin-bottom: var(--spacing-sm);
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 4px;
    background: var(--gradient-primary);
    border-radius: 2px;
}

.section-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin: 0 auto;
    margin-top: var(--spacing-md);
}

/* ==========================================
   特色功能区
   ========================================== */
.features {
    background: var(--bg-darker);
}

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

.feature-card {
    background: var(--gradient-card);
    border: 1px solid rgba(0, 0, 0, 0.1);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-lg);
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.feature-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--gradient-primary);
    transform: scaleX(0);
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-8px);
    border-color: var(--primary-color);
    box-shadow: var(--box-shadow-hover);
}

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

.feature-icon {
    width: 70px;
    height: 70px;
    background: var(--gradient-primary);
    border-radius: var(--border-radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
    transition: var(--transition);
}

.feature-card:hover .feature-icon {
    transform: scale(1.1) rotate(5deg);
}

.feature-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    font-family: var(--font-heading);
}

.feature-description {
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
    line-height: 1.7;
}

.feature-list {
    list-style: none;
}

.feature-list li {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

.feature-list i {
    color: var(--primary-color);
    font-size: 0.875rem;
}

/* ==========================================
   适用人群区
   ========================================== */
.audience-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-md);
}

.audience-card {
    background: var(--gradient-card);
    border: 1px solid rgba(0, 0, 0, 0.1);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-lg);
    text-align: center;
    transition: var(--transition);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.audience-card:hover {
    transform: translateY(-8px);
    border-color: var(--primary-color);
    box-shadow: var(--box-shadow);
}

.audience-icon {
    width: 80px;
    height: 80px;
    background: rgba(255, 36, 73, 0.06);
    border: 2px solid var(--primary-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    color: var(--primary-color);
    margin: 0 auto var(--spacing-md);
    transition: var(--transition);
}

.audience-card:hover .audience-icon {
    background: var(--gradient-primary);
    border-color: transparent;
    color: var(--text-primary);
    transform: scale(1.1);
}

.audience-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
}

.audience-card p {
    color: var(--text-secondary);
    line-height: 1.6;
}

/* ==========================================
   最新动态区
   ========================================== */
.news {
    background: var(--bg-darker);
}

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

.news-card {
    background: var(--gradient-card);
    border: 1px solid rgba(0, 0, 0, 0.1);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-md);
    display: flex;
    gap: var(--spacing-md);
    transition: var(--transition);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.news-card:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    box-shadow: var(--box-shadow);
}

.news-date {
    flex-shrink: 0;
    width: 70px;
    height: 70px;
    background: var(--gradient-primary);
    border-radius: var(--border-radius);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    font-weight: 700;
}

.date-day {
    font-size: 1.75rem;
    line-height: 1;
}

.date-month {
    font-size: 0.875rem;
    opacity: 0.9;
}

.news-content {
    flex: 1;
}

.news-tag {
    display: inline-block;
    background: rgba(255, 36, 73, 0.08);
    color: var(--primary-color);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: var(--spacing-sm);
}

.news-title {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    line-height: 1.4;
}

.news-description {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.6;
    margin-bottom: var(--spacing-sm);
}

.news-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
}

.news-link:hover {
    gap: 0.75rem;
}

.news-link i {
    font-size: 0.875rem;
    transition: var(--transition);
}

/* ==========================================
   常见问题区
   ========================================== */
.faq-container {
    max-width: 900px;
    margin: 0 auto;
}

.faq-item {
    background: var(--gradient-card);
    border: 1px solid rgba(0, 0, 0, 0.1);
    border-radius: var(--border-radius-lg);
    margin-bottom: var(--spacing-md);
    overflow: hidden;
    transition: var(--transition);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

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

.faq-question {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md);
    background: none;
    border: none;
    color: var(--text-primary);
    font-size: 1.125rem;
    font-weight: 600;
    text-align: left;
    cursor: pointer;
    transition: var(--transition);
    font-family: var(--font-primary);
}

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

.faq-question i {
    font-size: 1rem;
    color: var(--primary-color);
    transition: var(--transition);
}

.faq-item.active .faq-question i {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.faq-item.active .faq-answer {
    max-height: 500px;
}

.faq-answer p {
    padding: 0 var(--spacing-md) var(--spacing-md);
    color: var(--text-secondary);
    line-height: 1.8;
}

/* ==========================================
   用户评价区
   ========================================== */
.reviews {
    background: var(--bg-darker);
}

.review-stats {
    background: var(--gradient-card);
    border: 1px solid rgba(0, 0, 0, 0.12);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.rating-overview {
    text-align: center;
}

.rating-score {
    font-size: 4rem;
    font-weight: 900;
    font-family: var(--font-heading);
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    line-height: 1;
    margin-bottom: 0.5rem;
}

.rating-stars {
    font-size: 1.5rem;
    color: var(--accent-color);
    margin-bottom: 0.5rem;
}

.rating-count {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.rating-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    flex: 1;
    justify-content: center;
}

.rating-tags .tag {
    background: rgba(255, 36, 73, 0.08);
    color: var(--primary-color);
    padding: 0.5rem 1rem;
    border-radius: 50px;
    font-size: 0.95rem;
    font-weight: 500;
    border: 1px solid rgba(255, 36, 73, 0.3);
    transition: var(--transition);
}

.rating-tags .tag:hover {
    background: var(--primary-color);
    color: var(--bg-dark);
    border-color: var(--primary-color);
}

.reviews-slider {
    position: relative;
    overflow: hidden;
    padding: var(--spacing-md) 0;
}

.reviews-track {
    display: flex;
    gap: var(--spacing-md);
    transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.review-card {
    flex: 0 0 calc(33.333% - var(--spacing-md));
    background: var(--gradient-card);
    border: 1px solid rgba(0, 0, 0, 0.1);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-md);
    transition: var(--transition);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
}

.review-card:hover {
    transform: translateY(-5px);
    border-color: var(--primary-color);
    box-shadow: var(--box-shadow);
}

.review-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: var(--spacing-md);
}

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

.reviewer-avatar {
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    flex-shrink: 0;
}

.reviewer-name {
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.reviewer-role {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.review-rating {
    color: var(--accent-color);
    font-size: 0.875rem;
}

.review-text {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: var(--spacing-sm);
}

.review-date {
    font-size: 0.875rem;
    color: var(--text-muted);
}

.slider-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    border: none;
    border-radius: 50%;
    color: var(--text-primary);
    font-size: 1.25rem;
    cursor: pointer;
    transition: var(--transition);
    z-index: 10;
}

.slider-btn:hover {
    transform: translateY(-50%) scale(1.1);
    box-shadow: var(--box-shadow);
}

.slider-btn.prev {
    left: -25px;
}

.slider-btn.next {
    right: -25px;
}

.slider-dots {
    display: flex;
    justify-content: center;
    gap: 0.75rem;
    margin-top: var(--spacing-md);
}

.slider-dots .dot {
    width: 12px;
    height: 12px;
    background: rgba(255, 36, 73, 0.3);
    border-radius: 50%;
    cursor: pointer;
    transition: var(--transition);
}

.slider-dots .dot.active {
    background: var(--primary-color);
    width: 32px;
    border-radius: 6px;
}

/* ==========================================
   CTA区域
   ========================================== */
.cta {
    background: var(--gradient-card);
    border-top: 1px solid rgba(0, 0, 0, 0.1);
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    position: relative;
    overflow: hidden;
}

.cta::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(circle at 50% 50%, rgba(255, 36, 73, 0.05) 0%, transparent 70%);
    pointer-events: none;
}

.cta-content {
    position: relative;
    text-align: center;
    padding: var(--spacing-lg) 0;
}

.cta-title {
    font-size: 2.5rem;
    font-weight: 800;
    font-family: var(--font-heading);
    margin-bottom: var(--spacing-md);
}

.cta-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-lg);
}

/* ==========================================
   Footer
   ========================================== */
.footer {
    background: var(--bg-darker);
    border-top: 1px solid rgba(0, 0, 0, 0.1);
    padding: var(--spacing-xl) 0 var(--spacing-md);
}

.footer-main {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr 1fr;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
    font-family: var(--font-heading);
}

.footer-logo .logo-img {
    height: 2rem;
    width: auto;
    display: block;
}

.footer-description {
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: var(--spacing-md);
}

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

.footer-social a {
    width: 40px;
    height: 40px;
    background: rgba(255, 36, 73, 0.06);
    border: 1px solid rgba(255, 36, 73, 0.3);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
}

.footer-social a:hover {
    background: var(--gradient-primary);
    border-color: transparent;
    color: var(--text-primary);
    transform: translateY(-3px);
}

.footer-title {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.footer-links {
    list-style: none;
}

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

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--primary-color);
    padding-left: 5px;
}

.footer-bottom {
    border-top: 1px solid rgba(0, 0, 0, 0.1);
    padding-top: var(--spacing-md);
    text-align: center;
    color: var(--text-muted);
}

.footer-disclaimer {
    margin-top: 0.5rem;
    font-size: 0.875rem;
}

/* ==========================================
   返回顶部按钮
   ========================================== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    background: var(--gradient-primary);
    border: none;
    border-radius: 50%;
    color: var(--text-primary);
    font-size: 1.25rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    z-index: 999;
    box-shadow: 0 4px 16px rgba(255, 36, 73, 0.3);
}

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

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 24px rgba(255, 36, 73, 0.5);
}

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

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ==========================================
   响应式设计
   ========================================== */
@media (max-width: 992px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .section-title {
        font-size: 2.5rem;
    }
    
    .hero-stats {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-main {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .review-card {
        flex: 0 0 calc(50% - var(--spacing-md));
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: rgba(255, 255, 255, 0.98);
        flex-direction: column;
        padding: var(--spacing-md);
        gap: var(--spacing-sm);
        transform: translateX(-100%);
        transition: var(--transition);
        border-bottom: 1px solid rgba(0, 0, 0, 0.1);
    }
    
    .nav-menu.active {
        transform: translateX(0);
    }
    
    .menu-toggle {
        display: flex;
    }
    
    .menu-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(8px, 8px);
    }
    
    .menu-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .menu-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -7px);
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .hero-cta {
        flex-direction: column;
        align-items: stretch;
    }
    
    .hero-stats {
        grid-template-columns: repeat(2, 1fr);
        gap: 0.75rem;
    }
    
    .stat-number {
        font-size: 1.75rem;
    }
    
    .audience-grid {
        grid-template-columns: 1fr;
    }
    
    .news-grid {
        grid-template-columns: 1fr;
    }
    
    .review-stats {
        flex-direction: column;
        text-align: center;
    }
    
    .review-card {
        flex: 0 0 100%;
    }
    
    .slider-btn {
        display: none;
    }
    
    .footer-main {
        grid-template-columns: 1fr;
    }
    
    .cta-title {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    :root {
        font-size: 14px;
    }
    
    .container {
        padding: 0 var(--spacing-sm);
    }
    
    .hero-title {
        font-size: 1.75rem;
    }
    
    .section-title {
        font-size: 1.75rem;
    }
    
    .news-card {
        flex-direction: column;
        text-align: center;
    }
    
    .news-date {
        margin: 0 auto;
    }
}