/* 全局样式 */
:root {
    --primary-blue: #1a365d;
    --dark-blue: #152e4d;
    --medium-blue: #2c5282;
    --accent-blue: #3182ce;
    --light-blue: #ebf8ff;
    --accent-orange: #f6ad55;
    --accent-yellow: #ecc94b;
    --accent-red: #f56565;
    --accent-green: #48bb78;
    --white: #ffffff;
    --gray-50: #f7fafc;
    --gray-100: #edf2f7;
    --gray-200: #e2e8f0;
    --gray-700: #4a5568;
    --gray-900: #1a202c;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
    color: var(--gray-900);
    line-height: 1.6;
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 顶部导航 */
.site-header {
    background-color: var(--white);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
    transition: all 0.3s ease;
}

.site-header.scrolled {
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.main-nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 0;
}

.logo-section .logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: var(--primary-blue);
    font-size: 24px;
    font-weight: 700;
}

.logo-section .logo i {
    font-size: 32px;
    color: var(--accent-yellow);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-menu a {
    text-decoration: none;
    color: var(--gray-700);
    font-weight: 500;
    font-size: 16px;
    transition: color 0.3s ease;
}

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

.btn-donate {
    background-color: var(--accent-yellow);
    color: var(--gray-900) !important;
    padding: 12px 24px;
    border-radius: 6px;
    font-weight: 600 !important;
    transition: all 0.3s ease !important;
}

.btn-donate:hover {
    background-color: var(--accent-orange);
    transform: translateY(-2px);
}

/* Hero区域 */
.hero-section {
    position: relative;
    min-height: 700px;
    padding: 120px 0;
    color: var(--white);
    text-align: center;
    display: flex;
    align-items: center;
    overflow: hidden;
}

.video-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 1;
}

.video-background video {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.video-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: radial-gradient(ellipse at center, rgba(26, 54, 93, 0.1) 0%, rgba(26, 54, 93, 0.4) 40%, rgba(26, 54, 93, 0.85) 100%);
}

.hero-section .container {
    position: relative;
    z-index: 2;
}

.video-controls {
    position: absolute;
    bottom: 30px;
    right: 30px;
    z-index: 3;
}

.play-pause-btn {
    background-color: rgba(255, 255, 255, 0.2);
    border: none;
    color: var(--white);
    width: 50px;
    height: 50px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 20px;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.play-pause-btn:hover {
    background-color: rgba(255, 255, 255, 0.3);
    transform: scale(1.1);
}

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

.hero-title {
    font-size: 56px;
    font-weight: 800;
    margin-bottom: 16px;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 28px;
    color: var(--accent-yellow);
    margin-bottom: 24px;
    font-weight: 600;
}

.hero-description {
    font-size: 20px;
    color: rgba(255, 255, 255, 0.9);
    margin-bottom: 40px;
    line-height: 1.8;
}

.hero-actions {
    display: flex;
    gap: 20px;
    justify-content: center;
}

.btn-primary {
    background-color: var(--accent-yellow);
    color: var(--gray-900);
    padding: 16px 40px;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    font-size: 18px;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.btn-primary:hover {
    background-color: var(--accent-orange);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(236, 201, 75, 0.3);
}

.btn-secondary {
    background-color: transparent;
    color: var(--white);
    padding: 16px 40px;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    font-size: 18px;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    border: 2px solid rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.5);
}

/* 数据统计区域 */
.stats-section {
    padding: 60px 0;
    background-color: var(--gray-50);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
}

.stat-card {
    text-align: center;
    padding: 32px 20px;
}

.stat-number {
    font-size: 48px;
    font-weight: 800;
    color: var(--primary-blue);
    margin-bottom: 8px;
}

.stat-label {
    font-size: 18px;
    color: var(--gray-700);
    font-weight: 500;
}

/* 通用section样式 */
section {
    padding: 80px 0;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-title {
    font-size: 40px;
    font-weight: 800;
    color: var(--gray-900);
    margin-bottom: 12px;
}

.section-subtitle {
    font-size: 20px;
    color: var(--gray-700);
}

/* 核心定位区域 */
.about-section {
    background-color: var(--white);
}

.about-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.about-card {
    background-color: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: 8px;
    padding: 40px 32px;
    text-align: center;
    transition: all 0.3s ease;
}

.about-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.1);
    border-color: var(--primary-blue);
}

.about-icon {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-blue), var(--medium-blue));
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 24px;
}

.about-icon i {
    font-size: 36px;
    color: var(--white);
}

.about-card h3 {
    font-size: 22px;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 12px;
}

.about-card p {
    font-size: 16px;
    color: var(--gray-700);
    line-height: 1.7;
}

/* 模式亮点 */
.models-section {
    background-color: var(--gray-50);
}

.models-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 40px;
}

.model-card {
    background-color: var(--white);
    border-radius: 12px;
    padding: 48px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
}

.model-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.12);
}

.model-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 32px;
    padding-bottom: 24px;
    border-bottom: 2px solid var(--gray-100);
}

.model-header i {
    font-size: 36px;
}

.business-model .model-header i {
    color: var(--primary-blue);
}

.public-model .model-header i {
    color: var(--accent-red);
}

.model-header h3 {
    font-size: 24px;
    font-weight: 700;
    color: var(--gray-900);
}

.model-content {
    display: flex;
    flex-direction: column;
    gap: 28px;
}

.model-item {
    padding-left: 20px;
    border-left: 3px solid var(--gray-200);
}

.business-model .model-item {
    border-left-color: var(--primary-blue);
}

.public-model .model-item {
    border-left-color: var(--accent-red);
}

.model-item h4 {
    font-size: 18px;
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.model-item p {
    font-size: 16px;
    color: var(--gray-700);
}

/* 社会价值 */
.impact-section {
    background-color: var(--white);
}

.impact-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 32px;
}

.impact-card {
    text-align: center;
    padding: 20px;
}

.impact-icon {
    margin-bottom: 24px;
}

.impact-icon img {
    width: 80px;
    height: 80px;
    border-radius: 50%;
}

.impact-card h3 {
    font-size: 20px;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 12px;
}

.impact-card p {
    font-size: 15px;
    color: var(--gray-700);
    line-height: 1.7;
}

/* 系统入口 */
.systems-section {
    background-color: var(--gray-50);
}

.systems-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.system-card {
    background-color: var(--white);
    border-radius: 12px;
    padding: 40px 32px;
    text-align: center;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.system-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.12);
}

.system-icon {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
}

.system-icon i {
    font-size: 48px;
    color: var(--white);
}

.wl-icon {
    background: linear-gradient(135deg, #667eea, #764ba2);
}

.ds-icon {
    background: linear-gradient(135deg, #f093fb, #f5576c);
}

.zf-icon {
    background: linear-gradient(135deg, #4facfe, #00f2fe);
}

.system-card h3 {
    font-size: 22px;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 12px;
}

.system-desc {
    color: var(--gray-700);
    font-size: 15px;
    margin-bottom: 20px;
    line-height: 1.7;
}

.system-features {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 8px;
    margin-bottom: 24px;
}

.feature-tag {
    background-color: var(--gray-100);
    color: var(--gray-700);
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 6px;
}

.feature-tag i {
    color: var(--accent-green);
    font-size: 14px;
}

.btn-system {
    padding: 14px 36px;
    border-radius: 6px;
    font-weight: 600;
    font-size: 16px;
    transition: all 0.3s ease;
    border: none;
    color: var(--white);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    width: auto;
}

.btn-wl {
    background: linear-gradient(135deg, #667eea, #764ba2);
}

.btn-ds {
    background: linear-gradient(135deg, #f093fb, #f5576c);
}

.btn-zf {
    background: linear-gradient(135deg, #4facfe, #00f2fe);
}

.btn-system:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
    color: var(--white);
}

/* 联系我们 */
.contact-section {
    background-color: var(--white);
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.contact-card {
    background-color: var(--gray-50);
    border-radius: 12px;
    padding: 40px 32px;
    text-align: center;
    transition: all 0.3s ease;
}

.contact-card:hover {
    background-color: var(--white);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.contact-icon {
    width: 70px;
    height: 70px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary-blue), var(--medium-blue));
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
}

.contact-icon i {
    font-size: 30px;
    color: var(--white);
}

.contact-card h3 {
    font-size: 18px;
    font-weight: 700;
    color: var(--gray-900);
    margin-bottom: 10px;
}

.contact-card p {
    color: var(--gray-700);
    font-size: 15px;
}

/* 页脚 */
.site-footer {
    background-color: var(--primary-blue);
    color: var(--white);
    padding: 60px 0 30px;
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 3fr;
    gap: 60px;
    margin-bottom: 40px;
    padding-bottom: 40px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-logo a {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
    color: var(--white);
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 16px;
}

.footer-logo a i {
    font-size: 30px;
    color: var(--accent-yellow);
}

.footer-slogan {
    color: rgba(255, 255, 255, 0.8);
    font-size: 15px;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
}

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

.footer-column a {
    display: block;
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    margin-bottom: 12px;
    font-size: 15px;
    transition: color 0.3s ease;
}

.footer-column a:hover {
    color: var(--accent-yellow);
}

.social-links {
    display: flex;
    gap: 16px;
}

.social-links a {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 20px;
    transition: all 0.3s ease;
    text-decoration: none;
}

.social-links a:hover {
    background-color: var(--accent-yellow);
    color: var(--gray-900);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: rgba(255, 255, 255, 0.7);
    font-size: 14px;
}

.footer-legal {
    display: flex;
    gap: 24px;
}

.footer-legal a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-legal a:hover {
    color: var(--accent-yellow);
}

.footer-icp {
    display: flex;
    align-items: center;
}

.footer-icp a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    font-size: 14px;
    transition: color 0.3s ease;
}

.footer-icp a:hover {
    color: var(--accent-yellow);
}

/* 响应式设计 */
@media (max-width: 992px) {
    .hero-title {
        font-size: 42px;
    }
    
    .hero-subtitle {
        font-size: 24px;
    }
    
    .stats-grid,
    .about-grid,
    .impact-grid,
    .systems-grid,
    .contact-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .models-grid {
        grid-template-columns: 1fr;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .main-nav {
        flex-direction: column;
        gap: 20px;
    }
    
    .nav-menu {
        flex-wrap: wrap;
        justify-content: center;
        gap: 20px;
    }
    
    .hero-title {
        font-size: 32px;
    }
    
    .hero-subtitle {
        font-size: 20px;
    }
    
    .hero-description {
        font-size: 16px;
    }
    
    .hero-actions {
        flex-direction: column;
    }
    
    .section-title {
        font-size: 32px;
    }
    
    .stats-grid,
    .about-grid,
    .impact-grid,
    .systems-grid,
    .contact-grid,
    .footer-links {
        grid-template-columns: 1fr;
    }
    
    .footer-bottom {
        flex-direction: column;
        gap: 16px;
        text-align: center;
    }
}