/* ==================== 全局样式 ==================== */
:root {
    --primary: #2563eb;
    --primary-light: #3b82f6;
    --primary-dark: #1d4ed8;
    --secondary: #0ea5e9;
    --accent: #06b6d4;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --info: #6366f1;
    
    --bg-primary: #f8fafc;
    --bg-secondary: #f1f5f9;
    --bg-white: #ffffff;
    --bg-dark: #0f172a;
    
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    --text-white: #ffffff;
    
    --border: #e2e8f0;
    --border-light: #f1f5f9;
    
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow: 0 4px 6px -1px rgba(0,0,0,0.1);
    --shadow-md: 0 10px 15px -3px rgba(0,0,0,0.1);
    --shadow-lg: 0 20px 25px -5px rgba(0,0,0,0.1);
    
    --radius: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    color: var(--text-primary);
    background: var(--bg-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
}

ul, ol {
    list-style: none;
}

img {
    max-width: 100%;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ==================== 按钮样式 ==================== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    border: none;
    border-radius: var(--radius);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
    white-space: nowrap;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow);
}

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

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

.btn-sm {
    padding: 6px 12px;
    font-size: 13px;
}

.btn-lg {
    padding: 14px 28px;
    font-size: 16px;
}

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

/* ==================== 头部导航 ==================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

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

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 700;
    color: var(--primary);
}

.logo i {
    font-size: 28px;
}

.nav {
    display: flex;
    gap: 8px;
}

.nav-link {
    padding: 8px 16px;
    border-radius: var(--radius);
    font-size: 15px;
    font-weight: 500;
    color: var(--text-secondary);
    transition: var(--transition);
}

.nav-link:hover,
.nav-link.active {
    color: var(--primary);
    background: rgba(37, 99, 235, 0.1);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 12px;
}

.search-box {
    position: relative;
    display: flex;
    align-items: center;
}

.search-box i {
    position: absolute;
    left: 12px;
    color: var(--text-light);
}

.search-box input {
    padding: 8px 12px 8px 36px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 14px;
    width: 200px;
    transition: var(--transition);
}

.search-box input:focus {
    outline: none;
    border-color: var(--primary);
    width: 260px;
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    color: var(--text-primary);
    cursor: pointer;
}

/* 移动端菜单 */
.mobile-menu {
    position: fixed;
    top: 0;
    right: -300px;
    width: 300px;
    height: 100vh;
    background: white;
    z-index: 1001;
    transition: right 0.3s ease;
    box-shadow: var(--shadow-lg);
}

.mobile-menu.active {
    right: 0;
}

.mobile-menu-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    border-bottom: 1px solid var(--border);
}

.mobile-nav {
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.mobile-nav-link {
    padding: 12px 16px;
    border-radius: var(--radius);
    font-size: 16px;
    color: var(--text-secondary);
    transition: var(--transition);
}

.mobile-nav-link:hover {
    background: var(--bg-secondary);
    color: var(--primary);
}

/* ==================== 主内容 ==================== */
.main-content {
    padding-top: 70px;
}

.section {
    padding: 80px 0;
}

/* ==================== Hero区域 ==================== */
.hero-section {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    background: linear-gradient(135deg, #1e3a8a 0%, #2563eb 50%, #0ea5e9 100%);
    color: white;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    overflow: hidden;
}

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

.hero-content {
    position: relative;
    z-index: 2;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-title {
    font-size: 48px;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 24px;
}

.hero-subtitle {
    font-size: 18px;
    line-height: 1.8;
    opacity: 0.9;
    margin-bottom: 40px;
    max-width: 700px;
}

@media (max-width: 768px) {
    .hero-title {
        font-size: 32px;
    }
    .hero-subtitle {
        font-size: 15px;
    }
}

.title-sub {
    display: block;
    font-size: 18px;
    font-weight: 400;
    opacity: 0.9;
    margin-bottom: 8px;
}

.title-main {
    display: block;
    font-size: 48px;
    font-weight: 800;
    line-height: 1.2;
}

.hero-desc {
    font-size: 18px;
    line-height: 1.8;
    opacity: 0.9;
    margin-bottom: 40px;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    margin-bottom: 40px;
}

.stat-item {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 36px;
    font-weight: 800;
}

.stat-label {
    font-size: 14px;
    opacity: 0.8;
}

.hero-actions {
    display: flex;
    gap: 16px;
}

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

.hero-actions .btn-primary:hover {
    background: var(--bg-secondary);
}

.hero-actions .btn-outline {
    border-color: white;
    color: white;
}

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

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

.cell-animation {
    position: relative;
    width: 400px;
    height: 400px;
}

.cell {
    position: absolute;
    border-radius: 50%;
    opacity: 0.6;
    animation: float 6s ease-in-out infinite;
}

.cell-1 {
    width: 80px;
    height: 80px;
    background: rgba(255,255,255,0.2);
    top: 10%;
    left: 20%;
    animation-delay: 0s;
}

.cell-2 {
    width: 60px;
    height: 60px;
    background: rgba(255,255,255,0.15);
    top: 60%;
    left: 70%;
    animation-delay: 1s;
}

.cell-3 {
    width: 100px;
    height: 100px;
    background: rgba(255,255,255,0.1);
    top: 70%;
    left: 10%;
    animation-delay: 2s;
}

.cell-4 {
    width: 50px;
    height: 50px;
    background: rgba(255,255,255,0.2);
    top: 20%;
    left: 75%;
    animation-delay: 3s;
}

.cell-5 {
    width: 70px;
    height: 70px;
    background: rgba(255,255,255,0.12);
    top: 80%;
    left: 50%;
    animation-delay: 4s;
}

@keyframes float {
    0%, 100% { transform: translateY(0) scale(1); }
    50% { transform: translateY(-20px) scale(1.05); }
}

.dna-helix {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 200px;
    height: 300px;
}

.dna-strand {
    position: absolute;
    width: 100%;
    height: 20%;
    border: 3px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    animation: helix 3s linear infinite;
}

.dna-strand:nth-child(1) { top: 0%; animation-delay: 0s; }
.dna-strand:nth-child(2) { top: 20%; animation-delay: 0.3s; }
.dna-strand:nth-child(3) { top: 40%; animation-delay: 0.6s; }
.dna-strand:nth-child(4) { top: 60%; animation-delay: 0.9s; }
.dna-strand:nth-child(5) { top: 80%; animation-delay: 1.2s; }

@keyframes helix {
    0% { transform: rotateY(0deg); }
    100% { transform: rotateY(360deg); }
}

.hero-wave {
    position: absolute;
    bottom: -1px;
    left: 0;
    right: 0;
}

.hero-wave svg {
    display: block;
    width: 100%;
    height: 80px;
}

/* ==================== 区块头部 ==================== */
.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-tag {
    display: inline-block;
    padding: 6px 16px;
    background: rgba(37, 99, 235, 0.1);
    color: var(--primary);
    border-radius: 20px;
    font-size: 13px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 16px;
}

.section-title {
    font-size: 36px;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 16px;
}

.section-desc {
    font-size: 18px;
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto;
}

/* ==================== 特色卡片 ==================== */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
}

.feature-card {
    background: white;
    border-radius: var(--radius-lg);
    padding: 40px 30px;
    text-align: center;
    transition: var(--transition);
    border: 1px solid var(--border);
}

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

.feature-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 24px;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 32px;
    color: white;
}

.feature-card h3 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.feature-card p {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* ==================== 技术资料模块 ==================== */
.tech-section {
    background: var(--bg-primary);
}

.tech-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 30px;
    justify-content: center;
}

.tech-tab {
    padding: 10px 20px;
    border: 2px solid var(--border);
    border-radius: 30px;
    background: white;
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 6px;
}

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

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

.tech-filter-bar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    flex-wrap: wrap;
    gap: 16px;
}

.filter-left {
    flex: 1;
    max-width: 400px;
}

.search-input-group {
    position: relative;
    display: flex;
    align-items: center;
}

.search-input-group i {
    position: absolute;
    left: 14px;
    color: var(--text-light);
}

.search-input-group input {
    width: 100%;
    padding: 10px 14px 10px 40px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 14px;
}

.search-input-group input:focus {
    outline: none;
    border-color: var(--primary);
}

.filter-select {
    padding: 10px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 14px;
    background: white;
    cursor: pointer;
}

/* 技术文档卡片 */
.tech-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 24px;
    margin-bottom: 40px;
}

.tech-card {
    background: white;
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid var(--border);
    transition: var(--transition);
    cursor: pointer;
}

.tech-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary);
}

.tech-card-header {
    padding: 20px;
    border-bottom: 1px solid var(--border-light);
}

.tech-card-badge {
    display: inline-block;
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    margin-bottom: 8px;
}

.badge-extraction { background: #dbeafe; color: #1d4ed8; }
.badge-processing { background: #d1fae5; color: #065f46; }
.badge-qc { background: #fef3c7; color: #92400e; }
.badge-transfusion { background: #fce7f3; color: #9d174d; }
.badge-storage { background: #e0e7ff; color: #3730a3; }
.badge-safety { background: #fee2e2; color: #991b1b; }

.tech-card-title {
    font-size: 17px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 8px;
    line-height: 1.4;
}

.tech-card-body {
    padding: 16px 20px;
}

.tech-card-desc {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 16px;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.tech-card-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 13px;
    color: var(--text-light);
}

.tech-card-meta span {
    display: flex;
    align-items: center;
    gap: 4px;
}

/* ==================== 视频教学中心入口卡片 ==================== */
.video-section {
    padding: 80px 0;
    background: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
}

.video-cards-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
    max-width: 900px;
    margin: 0 auto;
}

.video-cards-grid .video-card {
    display: flex;
    flex-direction: column;
    background: white;
    border-radius: var(--radius-lg);
    overflow: hidden;
    border: 1px solid var(--border);
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.video-cards-grid .video-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary);
}

.video-cards-grid .video-card-thumb {
    width: 100%;
    height: 160px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 56px;
    color: white;
}

.video-cards-grid .video-card:first-child .video-card-thumb {
    background: linear-gradient(135deg, #2563eb, #0ea5e9);
}

.video-cards-grid .video-card:last-child .video-card-thumb {
    background: linear-gradient(135deg, #7c3aed, #a855f7);
}

.video-cards-grid .video-card-body {
    padding: 24px 28px 28px;
    display: flex;
    flex-direction: column;
    flex: 1;
}

.video-cards-grid .video-card-body h3 {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 10px;
}

.video-cards-grid .video-card-body p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.7;
    margin-bottom: 16px;
    flex: 1;
}

.video-card-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 14px;
    font-weight: 600;
    color: var(--primary);
    transition: var(--transition);
}

.video-cards-grid .video-card:hover .video-card-link {
    gap: 12px;
}

.video-card-link i {
    font-size: 12px;
    transition: transform 0.3s ease;
}

.video-cards-grid .video-card:hover .video-card-link i {
    transform: translateX(3px);
}

@media (max-width: 768px) {
    .video-cards-grid {
        grid-template-columns: 1fr;
    }
}

/* ==================== 快速入口 ==================== */
.quick-links-section {
    padding: 60px 0 80px;
    background: var(--bg-primary);
}

.quick-links-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.quick-link-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    padding: 32px 20px;
    background: white;
    border-radius: var(--radius-md);
    border: 1px solid var(--border);
    text-align: center;
    transition: var(--transition);
}

.quick-link-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    border-color: var(--primary);
}

.quick-link-card i {
    font-size: 32px;
    color: var(--primary);
    margin-bottom: 4px;
}

.quick-link-card h3 {
    font-size: 16px;
    font-weight: 700;
    color: var(--text-primary);
}

.quick-link-card p {
    font-size: 13px;
    color: var(--text-secondary);
}

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

@media (max-width: 480px) {
    .quick-links-grid {
        grid-template-columns: 1fr 1fr;
    }
}

/* ==================== 模态框 ==================== */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.5);
    z-index: 2000;
    display: none;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.modal-overlay.active {
    display: flex;
}

.modal {
    background: white;
    border-radius: var(--radius-lg);
    width: 100%;
    max-width: 600px;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
}

.modal.modal-lg {
    max-width: 900px;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 24px;
    border-bottom: 1px solid var(--border);
}

.modal-title {
    font-size: 20px;
    font-weight: 700;
}

.modal-close {
    background: none;
    border: none;
    font-size: 24px;
    color: var(--text-light);
    cursor: pointer;
    padding: 4px;
}

.modal-close:hover {
    color: var(--text-primary);
}

.modal-body {
    padding: 24px;
}

/* ==================== 表单样式 ==================== */
.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.form-control {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 14px;
    transition: var(--transition);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

/* ==================== 页脚 ==================== */
.footer {
    background: var(--bg-dark);
    color: rgba(255,255,255,0.8);
    padding: 60px 0;
}

.footer-content {
    text-align: center;
}

.footer-brand {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 700;
    color: white;
    margin-bottom: 12px;
}

.footer-brand i {
    font-size: 28px;
    color: var(--primary-light);
}

.footer-desc {
    font-size: 14px;
    color: rgba(255,255,255,0.6);
    margin-bottom: 8px;
}

.footer-copy {
    font-size: 13px;
    color: rgba(255,255,255,0.4);
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-col .logo {
    margin-bottom: 16px;
}

.footer-col p {
    font-size: 14px;
    line-height: 1.7;
    margin-bottom: 8px;
}

.footer-col h4 {
    font-size: 16px;
    font-weight: 700;
    color: white;
    margin-bottom: 20px;
}

.footer-col a {
    display: block;
    font-size: 14px;
    color: rgba(255,255,255,0.7);
    margin-bottom: 10px;
    transition: var(--transition);
}

.footer-col a:hover {
    color: white;
    padding-left: 4px;
}

.footer-col i {
    margin-right: 8px;
    color: var(--primary-light);
}

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding: 20px 0;
    text-align: center;
    font-size: 14px;
}

/* ==================== 回到顶部 ==================== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--primary);
    color: white;
    border: none;
    cursor: pointer;
    font-size: 20px;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    opacity: 0;
    visibility: hidden;
    z-index: 999;
}

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

.back-to-top:hover {
    background: var(--primary-dark);
    transform: translateY(-3px);
}

/* ==================== 分页 ==================== */
.pagination {
    display: flex;
    justify-content: center;
    gap: 8px;
    margin-top: 40px;
}

.page-btn {
    width: 40px;
    height: 40px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    background: white;
    color: var(--text-secondary);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
}

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

/* ==================== 响应式设计 ==================== */
@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-visual {
        display: none;
    }
    
    .hero-stats {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .features-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .footer-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    .nav {
        display: none;
    }
    
    .search-box {
        display: none;
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    .title-main {
        font-size: 32px;
    }
    
    .hero-stats {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .features-grid {
        grid-template-columns: 1fr;
    }
    
    .tech-grid {
        grid-template-columns: 1fr;
    }
    
    .section-title {
        font-size: 28px;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
    }
    
    .tech-tabs {
        flex-wrap: nowrap;
        overflow-x: auto;
        justify-content: flex-start;
        padding-bottom: 10px;
    }
}

@media (max-width: 480px) {
    .hero-actions {
        flex-direction: column;
    }
    
    .btn-lg {
        width: 100%;
        justify-content: center;
    }
}