/* ========================================
   肝种子再生计划 - 样式系统
   设计风格：温暖治愈关怀风
   ======================================== */

/* CSS变量定义 */
:root {
    /* 主色调 - 生命绿系 */
    --color-primary: #2D8A5E;
    --color-primary-dark: #1E6B47;
    --color-primary-light: #4CA87A;
    --color-primary-lighter: #E8F5EE;
    
    /* 辅助色 - 温暖米白 */
    --color-bg: #FAF8F5;
    --color-bg-alt: #F5F2ED;
    --color-white: #FFFFFF;
    
    /* 强调色 - 希望金 */
    --color-accent: #D4A853;
    --color-accent-light: #E8C87A;
    
    /* 文字色 */
    --color-text: #2C3E33;
    --color-text-light: #5A6B5F;
    --color-text-muted: #8A9A8F;
    
    /* 字体 */
    --font-serif: 'Noto Serif SC', serif;
    --font-sans: 'Noto Sans SC', sans-serif;
    
    /* 间距 */
    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 1.5rem;
    --space-lg: 2.5rem;
    --space-xl: 4rem;
    --space-2xl: 6rem;
    
    /* 圆角 */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --radius-full: 9999px;
    
    /* 阴影 */
    --shadow-sm: 0 2px 8px rgba(45, 138, 94, 0.08);
    --shadow-md: 0 4px 20px rgba(45, 138, 94, 0.12);
    --shadow-lg: 0 8px 40px rgba(45, 138, 94, 0.16);
    
    /* 过渡 */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* 重置样式 */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    font-family: var(--font-sans);
    font-weight: 400;
    line-height: 1.7;
    color: var(--color-text);
    background-color: var(--color-bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

a {
    text-decoration: none;
    color: inherit;
    transition: color var(--transition-fast);
}

ul {
    list-style: none;
}

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* 容器 */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--space-md);
}

/* ========================================
   导航栏
   ======================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(250, 248, 245, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(45, 138, 94, 0.08);
    transition: all var(--transition-normal);
}

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

.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    font-family: var(--font-serif);
    font-weight: 600;
    font-size: 1.25rem;
    color: var(--color-primary);
}

.logo-icon {
    font-size: 1.5rem;
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--space-lg);
}

.nav-link {
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--color-text-light);
    padding: 0.5rem 0;
    position: relative;
    transition: color var(--transition-fast);
}

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

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

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

/* 移动端菜单按钮 */
.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: 8px;
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-primary);
    transition: all var(--transition-fast);
}

/* ========================================
   Hero区域
   ======================================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 72px;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--color-bg) 0%, var(--color-primary-lighter) 50%, var(--color-bg-alt) 100%);
    z-index: -2;
}

.hero-particles {
    position: absolute;
    inset: 0;
    background-image: 
        radial-gradient(circle at 20% 80%, rgba(45, 138, 94, 0.08) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(212, 168, 83, 0.06) 0%, transparent 50%),
        radial-gradient(circle at 40% 40%, rgba(45, 138, 94, 0.04) 0%, transparent 40%);
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-xl);
    align-items: center;
    padding: var(--space-xl) var(--space-md);
}

.hero-badge {
    display: inline-block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-primary);
    background: var(--color-primary-lighter);
    padding: 0.5rem 1rem;
    border-radius: var(--radius-full);
    margin-bottom: var(--space-md);
}

.hero-title {
    font-family: var(--font-serif);
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.2;
    color: var(--color-text);
    margin-bottom: var(--space-md);
}

.hero-title .highlight {
    color: var(--color-primary);
    position: relative;
    display: inline-block;
}

.hero-title .highlight::after {
    content: '';
    position: absolute;
    bottom: 5px;
    left: 0;
    right: 0;
    height: 12px;
    background: rgba(45, 138, 94, 0.15);
    z-index: -1;
    border-radius: 4px;
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--color-text-light);
    margin-bottom: var(--space-lg);
    line-height: 1.8;
}

.hero-cta {
    display: flex;
    gap: var(--space-sm);
    margin-bottom: var(--space-xl);
}

/* 按钮样式 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.875rem 1.75rem;
    font-size: 0.9375rem;
    font-weight: 600;
    border-radius: var(--radius-full);
    transition: all var(--transition-normal);
    cursor: pointer;
}

.btn-primary {
    background: var(--color-primary);
    color: var(--color-white);
    box-shadow: 0 4px 15px rgba(45, 138, 94, 0.3);
}

.btn-primary:hover {
    background: var(--color-primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(45, 138, 94, 0.4);
}

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

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

.btn-large {
    padding: 1rem 2.5rem;
    font-size: 1rem;
}

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

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

/* Hero统计数据 */
.hero-stats {
    display: flex;
    gap: var(--space-xl);
}

.stat-item {
    display: flex;
    flex-direction: column;
}

.stat-number {
    font-family: var(--font-serif);
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-primary);
}

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

/* Hero视觉动画 */
.hero-visual {
    display: flex;
    justify-content: center;
    align-items: center;
}

.liver-animation {
    position: relative;
    width: 300px;
    height: 300px;
}

.liver-shape {
    position: relative;
    z-index: 2;
    color: var(--color-primary);
}

.liver-shape svg {
    width: 100%;
    height: auto;
}

.liver-path {
    stroke-dasharray: 500;
    stroke-dashoffset: 500;
    animation: drawLiver 2s ease forwards;
}

@keyframes drawLiver {
    to {
        stroke-dashoffset: 0;
    }
}

.cell {
    fill: var(--color-accent);
    opacity: 0;
    animation: fadeInCell 0.5s ease forwards;
}

.cell-1 { animation-delay: 1.5s; }
.cell-2 { animation-delay: 1.7s; }
.cell-3 { animation-delay: 1.9s; }
.cell-4 { animation-delay: 2.1s; }
.cell-5 { animation-delay: 2.3s; }

@keyframes fadeInCell {
    to {
        opacity: 1;
    }
}

.pulse-rings {
    position: absolute;
    inset: 0;
    display: flex;
    justify-content: center;
    align-items: center;
}

.pulse-rings span {
    position: absolute;
    width: 100%;
    height: 100%;
    border: 2px solid var(--color-primary);
    border-radius: 50%;
    opacity: 0;
    animation: pulse 3s ease-out infinite;
}

.pulse-rings span:nth-child(2) {
    animation-delay: 1s;
}

.pulse-rings span:nth-child(3) {
    animation-delay: 2s;
}

@keyframes pulse {
    0% {
        transform: scale(0.8);
        opacity: 0.5;
    }
    100% {
        transform: scale(1.5);
        opacity: 0;
    }
}

/* 滚动指示器 */
.scroll-indicator {
    position: absolute;
    bottom: var(--space-lg);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-xs);
    color: var(--color-text-muted);
    font-size: 0.875rem;
    animation: bounce 2s infinite;
}

.scroll-arrow {
    width: 20px;
    height: 20px;
    border-right: 2px solid var(--color-primary);
    border-bottom: 2px solid var(--color-primary);
    transform: rotate(45deg);
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateX(-50%) translateY(0);
    }
    40% {
        transform: translateX(-50%) translateY(-10px);
    }
    60% {
        transform: translateX(-50%) translateY(-5px);
    }
}

/* ========================================
   通用Section样式
   ======================================== */
.section {
    padding: var(--space-2xl) 0;
}

.section-header {
    text-align: center;
    max-width: 600px;
    margin: 0 auto var(--space-xl);
}

.section-badge {
    display: inline-block;
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-primary);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: var(--space-sm);
}

.section-title {
    font-family: var(--font-serif);
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: var(--space-sm);
}

.section-desc {
    font-size: 1.125rem;
    color: var(--color-text-light);
}

/* ========================================
   PRP治疗区域
   ======================================== */
.section-prp {
    background: var(--color-white);
}

.prp-content {
    display: flex;
    flex-direction: column;
    gap: var(--space-xl);
}

.prp-intro {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-xl);
}

.prp-card {
    background: var(--color-bg);
    padding: var(--space-xl);
    border-radius: var(--radius-lg);
    border: 1px solid rgba(45, 138, 94, 0.1);
}

.prp-icon {
    font-size: 3rem;
    margin-bottom: var(--space-md);
}

.prp-card h3 {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    margin-bottom: var(--space-sm);
    color: var(--color-text);
}

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

.prp-benefits {
    padding: var(--space-xl);
}

.prp-benefits h4 {
    font-family: var(--font-serif);
    font-size: 1.25rem;
    margin-bottom: var(--space-md);
    color: var(--color-text);
}

.benefit-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.benefit-list li {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 1rem;
    color: var(--color-text-light);
}

.benefit-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 24px;
    height: 24px;
    background: var(--color-primary-lighter);
    color: var(--color-primary);
    border-radius: 50%;
    font-size: 0.75rem;
    font-weight: 700;
}

/* 治疗流程 */
.process-section {
    background: var(--color-primary-lighter);
    padding: var(--space-xl);
    border-radius: var(--radius-lg);
}

.process-title {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    text-align: center;
    margin-bottom: var(--space-xl);
    color: var(--color-text);
}

.process-steps {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: var(--space-md);
}

.step {
    flex: 1;
    text-align: center;
    position: relative;
}

.step-number {
    font-family: var(--font-serif);
    font-size: 0.875rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: var(--space-sm);
}

.step-content {
    background: var(--color-white);
    padding: var(--space-md);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.step-icon {
    font-size: 2rem;
    margin-bottom: var(--space-xs);
}

.step h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
    color: var(--color-text);
}

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

.step-connector {
    width: 40px;
    height: 2px;
    background: linear-gradient(90deg, var(--color-primary-light), var(--color-accent));
    margin-top: 3rem;
    flex-shrink: 0;
}

/* ========================================
   骨髓细胞治疗区域
   ======================================== */
.section-bone-marrow {
    background: linear-gradient(180deg, var(--color-bg) 0%, var(--color-bg-alt) 100%);
}

.bm-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.bm-card {
    background: var(--color-white);
    padding: var(--space-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
}

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

.bm-visual {
    height: 120px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: var(--space-md);
}

.cell-animation {
    display: flex;
    gap: var(--space-sm);
}

.stem-cell {
    width: 40px;
    height: 40px;
    background: radial-gradient(circle at 30% 30%, var(--color-primary-light), var(--color-primary));
    border-radius: 50%;
    animation: float 3s ease-in-out infinite;
}

.stem-cell:nth-child(2) {
    animation-delay: 0.5s;
    width: 30px;
    height: 30px;
}

.stem-cell:nth-child(3) {
    animation-delay: 1s;
    width: 35px;
    height: 35px;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-15px);
    }
}

.bm-card h3 {
    font-family: var(--font-serif);
    font-size: 1.25rem;
    margin-bottom: var(--space-sm);
    color: var(--color-text);
}

.bm-card p {
    font-size: 0.9375rem;
    color: var(--color-text-light);
    line-height: 1.7;
}

.suitable-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.suitable-list li {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    font-size: 0.9375rem;
    color: var(--color-text-light);
}

.check {
    color: var(--color-primary);
    font-weight: 700;
}

.effects-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-md);
}

.effect-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 0.5rem;
}

.effect-icon {
    font-size: 1.75rem;
}

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

/* ========================================
   肝硬化治疗区域
   ======================================== */
.section-cirrhosis {
    background: var(--color-white);
}

.treatment-tabs {
    max-width: 900px;
    margin: 0 auto;
}

.tab-headers {
    display: flex;
    justify-content: center;
    gap: var(--space-sm);
    margin-bottom: var(--space-xl);
}

.tab-btn {
    padding: 0.75rem 1.5rem;
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--color-text-light);
    background: var(--color-bg);
    border-radius: var(--radius-full);
    transition: all var(--transition-fast);
}

.tab-btn:hover {
    color: var(--color-primary);
}

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

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.treatment-info {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-xl);
    align-items: center;
}

.treatment-text h3 {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    margin-bottom: var(--space-sm);
    color: var(--color-text);
}

.treatment-text > p {
    color: var(--color-text-light);
    margin-bottom: var(--space-md);
    line-height: 1.7;
}

.treatment-points {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.treatment-points li {
    position: relative;
    padding-left: 1.5rem;
    color: var(--color-text-light);
    font-size: 0.9375rem;
}

.treatment-points li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--color-primary);
    font-weight: 700;
}

.treatment-visual {
    background: var(--color-bg);
    padding: var(--space-xl);
    border-radius: var(--radius-lg);
}

.liver-stage {
    text-align: center;
}

.stage-label {
    display: block;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--space-sm);
}

.stage-bar {
    height: 12px;
    background: var(--color-bg-alt);
    border-radius: var(--radius-full);
    overflow: hidden;
}

.stage-progress {
    height: 100%;
    background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
    border-radius: var(--radius-full);
    transition: width 1s ease;
}

/* ========================================
   关于我们区域
   ======================================== */
.section-about {
    background: var(--color-bg-alt);
}

.about-content {
    display: flex;
    flex-direction: column;
    gap: var(--space-2xl);
}

.about-intro {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-xl);
}

.about-text h3 {
    font-family: var(--font-serif);
    font-size: 1.75rem;
    margin-bottom: var(--space-md);
    color: var(--color-text);
}

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

.about-features {
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.feature-item {
    background: var(--color-white);
    padding: var(--space-md);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--color-primary);
}

.feature-number {
    font-family: var(--font-serif);
    font-size: 0.875rem;
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: 0.25rem;
    display: block;
}

.feature-item h4 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
    color: var(--color-text);
}

.feature-item p {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

/* 团队 */
.team-section {
    text-align: center;
}

.team-title {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    margin-bottom: var(--space-xl);
    color: var(--color-text);
}

.team-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.team-card {
    background: var(--color-white);
    padding: var(--space-xl);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-normal);
}

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

.team-avatar {
    width: 100px;
    height: 100px;
    margin: 0 auto var(--space-md);
    background: var(--color-primary-lighter);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.avatar-placeholder {
    font-size: 3rem;
}

.team-card h4 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 0.25rem;
    color: var(--color-text);
}

.team-role {
    font-size: 0.875rem;
    color: var(--color-primary);
    font-weight: 500;
    margin-bottom: var(--space-xs);
}

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

/* ========================================
   FAQ区域
   ======================================== */
.section-faq {
    background: var(--color-white);
}

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

.faq-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.faq-item {
    background: var(--color-bg);
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid rgba(45, 138, 94, 0.1);
}

.faq-question {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--space-md);
    font-size: 1rem;
    font-weight: 500;
    color: var(--color-text);
    text-align: left;
    transition: background var(--transition-fast);
}

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

.faq-icon {
    font-size: 1.25rem;
    color: var(--color-primary);
    transition: transform var(--transition-fast);
}

.faq-item.active .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-normal);
}

.faq-item.active .faq-answer {
    max-height: 300px;
}

.faq-answer p {
    padding: 0 var(--space-md) var(--space-md);
    color: var(--color-text-light);
    line-height: 1.7;
}

/* ========================================
   CTA区域
   ======================================== */
.section-cta {
    position: relative;
    background: var(--color-primary);
    padding: var(--space-2xl) 0;
    overflow: hidden;
}

.cta-bg {
    position: absolute;
    inset: 0;
    opacity: 0.1;
}

.cta-pattern {
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(circle at 25% 25%, white 2px, transparent 2px),
        radial-gradient(circle at 75% 75%, white 2px, transparent 2px);
    background-size: 60px 60px;
}

.cta-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: var(--color-white);
}

.cta-content h2 {
    font-family: var(--font-serif);
    font-size: 2.5rem;
    margin-bottom: var(--space-sm);
}

.cta-content p {
    font-size: 1.125rem;
    opacity: 0.9;
    margin-bottom: var(--space-xl);
}

.cta-buttons {
    display: flex;
    justify-content: center;
    gap: var(--space-md);
}

/* ========================================
   页脚
   ======================================== */
.footer {
    background: var(--color-text);
    color: var(--color-white);
    padding: var(--space-2xl) 0 var(--space-lg);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: var(--space-xl);
    margin-bottom: var(--space-xl);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: var(--space-xs);
    font-family: var(--font-serif);
    font-weight: 600;
    font-size: 1.25rem;
    margin-bottom: var(--space-sm);
}

.footer-desc {
    color: var(--color-text-muted);
    font-size: 0.9375rem;
    line-height: 1.7;
}

.footer-column h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--space-md);
    color: var(--color-white);
}

.footer-column ul {
    display: flex;
    flex-direction: column;
    gap: var(--space-xs);
}

.footer-column a {
    color: var(--color-text-muted);
    font-size: 0.9375rem;
    transition: color var(--transition-fast);
}

.footer-column a:hover {
    color: var(--color-primary-light);
}

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

.footer-bottom p {
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

.footer-disclaimer {
    margin-top: var(--space-xs);
    font-size: 0.8125rem;
}

/* ========================================
   响应式设计
   ======================================== */

/* 平板设备 (768px - 1024px) */
@media (max-width: 1024px) {
    .hero-title {
        font-size: 2.75rem;
    }
    
    .hero-content {
        gap: var(--space-lg);
    }
    
    .liver-animation {
        width: 250px;
        height: 250px;
    }
    
    .bm-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .team-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-content {
        grid-template-columns: 1fr 1fr;
    }
}

/* 移动设备 (< 768px) */
@media (max-width: 768px) {
    :root {
        --space-2xl: 4rem;
        --space-xl: 2.5rem;
    }
    
    /* 导航栏 */
    .nav-toggle {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        top: 72px;
        left: 0;
        right: 0;
        background: var(--color-white);
        flex-direction: column;
        padding: var(--space-md);
        gap: 0;
        box-shadow: var(--shadow-md);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-normal);
    }
    
    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-link {
        display: block;
        padding: var(--space-sm) 0;
        border-bottom: 1px solid var(--color-bg-alt);
    }
    
    .nav-link:last-child {
        border-bottom: none;
    }
    
    /* Hero区域 */
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-title {
        font-size: 2.25rem;
    }
    
    .hero-subtitle br {
        display: none;
    }
    
    .hero-cta {
        justify-content: center;
        flex-wrap: wrap;
    }
    
    .hero-stats {
        justify-content: center;
        gap: var(--space-lg);
    }
    
    .hero-visual {
        order: -1;
    }
    
    .liver-animation {
        width: 200px;
        height: 200px;
    }
    
    /* Section标题 */
    .section-title {
        font-size: 1.875rem;
    }
    
    /* PRP区域 */
    .prp-intro {
        grid-template-columns: 1fr;
    }
    
    .process-steps {
        flex-direction: column;
        gap: var(--space-md);
    }
    
    .step-connector {
        width: 2px;
        height: 30px;
        margin: 0 auto;
        background: linear-gradient(180deg, var(--color-primary-light), var(--color-accent));
    }
    
    /* 骨髓细胞区域 */
    .bm-grid {
        grid-template-columns: 1fr;
    }
    
    /* 肝硬化治疗 */
    .tab-headers {
        flex-wrap: wrap;
    }
    
    .treatment-info {
        grid-template-columns: 1fr;
    }
    
    /* 关于我们 */
    .about-intro {
        grid-template-columns: 1fr;
    }
    
    .team-grid {
        grid-template-columns: 1fr;
    }
    
    /* CTA */
    .cta-content h2 {
        font-size: 1.875rem;
    }
    
    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    /* 页脚 */
    .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .footer-logo {
        justify-content: center;
    }
}

/* 小屏移动设备 (< 480px) */
@media (max-width: 480px) {
    html {
        font-size: 14px;
    }
    
    .hero-title {
        font-size: 1.875rem;
    }
    
    .section-title {
        font-size: 1.5rem;
    }
    
    .btn {
        padding: 0.75rem 1.25rem;
        font-size: 0.875rem;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: var(--space-md);
    }
    
    .stat-item {
        align-items: center;
    }
}

/* ========================================
   动画效果
   ======================================== */

/* 滚动显示动画 */
.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

/* 打印样式 */
@media print {
    .navbar,
    .scroll-indicator,
    .hero-visual,
    .cta-bg {
        display: none;
    }
    
    .hero {
        min-height: auto;
        padding: var(--space-lg) 0;
    }
    
    .section {
        padding: var(--space-lg) 0;
        page-break-inside: avoid;
    }
}