/* ============================================
   细胞分裂：两种分裂方式 - 中文本地化版本
   优化移动端阅读体验
   ============================================ */

/* CSS变量 */
:root {
    --primary-color: #2c5aa0;
    --primary-dark: #1e3d6f;
    --primary-light: #4a7ac2;
    --secondary-color: #e74c3c;
    --accent-color: #27ae60;
    --text-primary: #2c3e50;
    --text-secondary: #5d6d7e;
    --text-light: #95a5a6;
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-accent: #e8f4f8;
    --border-color: #e1e8ed;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.1);
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --transition: all 0.3s ease;
    --container-max: 1200px;
    --font-sans: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: 1.8;
    color: var(--text-primary);
    background-color: var(--bg-primary);
}

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

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

a:hover {
    color: var(--primary-dark);
}

/* 容器 */
.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 1rem;
}

@media (min-width: 640px) {
    .container {
        padding: 0 1.5rem;
    }
}

@media (min-width: 1024px) {
    .container {
        padding: 0 2rem;
    }
}

/* ============================================
   页面标题
   ============================================ */
.page-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 2rem 0;
    text-align: center;
}

.page-title {
    font-size: 1.75rem;
    font-weight: 700;
    line-height: 1.3;
}

@media (min-width: 640px) {
    .page-header {
        padding: 3rem 0;
    }

    .page-title {
        font-size: 2.25rem;
    }
}

@media (min-width: 1024px) {
    .page-header {
        padding: 4rem 0;
    }

    .page-title {
        font-size: 2.75rem;
    }
}

/* ============================================
   内容区块
   ============================================ */
.content-section {
    padding: 2.5rem 0;
}

.content-section:nth-child(even) {
    background: var(--bg-secondary);
}

.section-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 1.5rem;
    text-align: center;
}

.section-intro {
    font-size: 1.125rem;
    color: var(--text-secondary);
    text-align: center;
    max-width: 700px;
    margin: 0 auto 2rem;
}

@media (min-width: 640px) {
    .content-section {
        padding: 3.5rem 0;
    }

    .section-title {
        font-size: 1.875rem;
        margin-bottom: 2rem;
    }
}

@media (min-width: 1024px) {
    .content-section {
        padding: 4rem 0;
    }

    .section-title {
        font-size: 2.25rem;
    }
}

/* ============================================
   介绍区块
   ============================================ */
.intro-content {
    max-width: 800px;
    margin: 0 auto;
}

.lead-text {
    font-size: 1.125rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.intro-content p {
    margin-bottom: 1rem;
}

.intro-content strong {
    color: var(--primary-color);
    font-weight: 600;
}

.related-content {
    background: var(--bg-accent);
    padding: 1.5rem;
    border-radius: var(--radius-md);
    margin-top: 2rem;
}

.related-content h3 {
    font-size: 1.125rem;
    color: var(--primary-color);
    margin-bottom: 0.75rem;
}

.related-links {
    list-style: none;
    padding-left: 0;
}

.related-links li {
    padding: 0.375rem 0;
    padding-left: 1.25rem;
    position: relative;
}

.related-links li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--primary-color);
}

/* ============================================
   视频区块
   ============================================ */
.video-grid {
    display: grid;
    gap: 1.5rem;
    margin-top: 2rem;
}

.video-card {
    background: var(--bg-primary);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.video-card h3 {
    padding: 1rem 1rem 0;
    font-size: 1.125rem;
    color: var(--primary-color);
}

.video-container {
    position: relative;
    padding-bottom: 56.25%; /* 16:9 */
    height: 0;
    overflow: hidden;
}

.video-container video,
.video-container iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

@media (min-width: 768px) {
    .video-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* ============================================
   术语区块
   ============================================ */
.terms-grid {
    display: grid;
    gap: 1.5rem;
    margin-top: 2rem;
}

.term-card {
    background: var(--bg-primary);
    padding: 1.5rem;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

.term-card h3 {
    font-size: 1.125rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.term-figure {
    margin: 0;
}

.term-figure img {
    width: 100%;
    max-height: 200px;
    object-fit: contain;
    margin-bottom: 0.75rem;
}

.term-figure figcaption {
    font-size: 0.875rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

@media (min-width: 640px) {
    .terms-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .terms-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

/* ============================================
   相似性提示框
   ============================================ */
.similarity-box {
    background: linear-gradient(135deg, #fff9e6 0%, #fff3cd 100%);
    border-left: 4px solid #f0ad4e;
    padding: 1.25rem;
    border-radius: var(--radius-sm);
    margin-bottom: 2rem;
}

.similarity-box h3 {
    color: #856404;
    font-size: 1rem;
    margin-bottom: 0.5rem;
}

.similarity-box p {
    color: #856404;
    margin: 0;
}

/* ============================================
   对比区块
   ============================================ */
.comparison-grid {
    display: grid;
    gap: 1.5rem;
}

.comparison-card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.25rem;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
}

.card-header h2 {
    font-size: 1.375rem;
    color: var(--primary-color);
}

.process-badge {
    display: inline-block;
    padding: 0.375rem 0.75rem;
    background: var(--primary-color);
    color: white;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 20px;
    text-transform: uppercase;
}

.process-badge.secondary {
    background: var(--accent-color);
}

.card-content {
    padding: 1.5rem;
}

.info-block {
    margin-bottom: 1.5rem;
}

.info-block h4 {
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.info-block p {
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

.result-block {
    background: var(--bg-accent);
    padding: 1rem;
    border-radius: var(--radius-sm);
    border-left: 3px solid var(--primary-color);
}

.process-figure {
    margin: 1.5rem 0 0;
    text-align: center;
}

.process-figure img {
    max-height: 250px;
    margin: 0 auto;
}

.process-figure figcaption {
    font-size: 0.875rem;
    color: var(--text-light);
    margin-top: 0.5rem;
}

@media (min-width: 1024px) {
    .comparison-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* ============================================
   机制区块
   ============================================ */
.machinery-article {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow-sm);
}

.machinery-header {
    margin-bottom: 1.5rem;
}

.machinery-header h3 {
    font-size: 1.25rem;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.job-badge {
    display: inline-block;
    font-size: 0.8125rem;
    color: var(--accent-color);
    font-weight: 500;
}

.machinery-content p {
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

.machinery-figure {
    margin: 1.5rem 0;
    text-align: center;
}

.machinery-figure img {
    max-height: 200px;
    margin: 0 auto 0.75rem;
}

.machinery-figure figcaption {
    font-size: 0.875rem;
    color: var(--text-light);
    font-style: italic;
}

.process-comparison {
    display: grid;
    gap: 1.5rem;
    margin-top: 2rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.process-detail {
    background: var(--bg-secondary);
    padding: 1.25rem;
    border-radius: var(--radius-md);
}

.process-detail h4 {
    font-size: 1.125rem;
    color: var(--primary-color);
    margin-bottom: 0.75rem;
}

.process-detail p {
    font-size: 0.9375rem;
    margin-bottom: 0.75rem;
}

.process-detail figure {
    margin-top: 1rem;
    text-align: center;
}

.process-detail img {
    max-height: 180px;
    margin: 0 auto;
}

@media (min-width: 768px) {
    .process-comparison {
        grid-template-columns: repeat(2, 1fr);
    }

    .machinery-article {
        padding: 2rem;
    }
}

/* ============================================
   健康区块
   ============================================ */
.health-grid {
    display: grid;
    gap: 1.5rem;
}

.health-card {
    background: var(--bg-primary);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.health-content {
    padding: 1.5rem;
}

.health-status {
    margin-bottom: 1.5rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.health-status:last-of-type {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.health-status h4 {
    display: inline-block;
    padding: 0.375rem 0.875rem;
    font-size: 0.875rem;
    font-weight: 600;
    border-radius: 20px;
    margin-bottom: 0.75rem;
}

.health-status.healthy h4 {
    background: #d4edda;
    color: #155724;
}

.health-status.problem h4 {
    background: #f8d7da;
    color: #721c24;
}

.health-status p {
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

.health-figure {
    margin-top: 1.5rem;
    text-align: center;
}

.health-figure img {
    max-height: 200px;
    margin: 0 auto;
}

.health-figure figcaption {
    font-size: 0.875rem;
    color: var(--text-light);
    margin-top: 0.5rem;
}

@media (min-width: 1024px) {
    .health-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* ============================================
   结语区块
   ============================================ */
.conclusion-section {
    background: var(--bg-secondary);
}

.conclusion-quote {
    background: var(--bg-primary);
    padding: 2rem;
    border-radius: var(--radius-lg);
    border-left: 4px solid var(--primary-color);
    box-shadow: var(--shadow-sm);
}

.conclusion-quote p {
    font-size: 1.125rem;
    font-style: italic;
    color: var(--text-secondary);
    line-height: 1.8;
}

/* ============================================
   辅助类
   ============================================ */
.text-center {
    text-align: center;
}

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

/* 加载优化 */
img[loading="lazy"] {
    opacity: 0;
    transition: opacity 0.3s;
}

img[loading="lazy"].loaded {
    opacity: 1;
}

/* 打印样式 */
@media print {
    .navbar,
    .breadcrumb,
    .video-section,
    .site-footer {
        display: none;
    }

    .content-section {
        padding: 1rem 0;
    }

    body {
        font-size: 12pt;
        line-height: 1.5;
    }
}