/* 全局样式 */
:root {
    --primary-color: #2563eb;
    --secondary-color: #1e40af;
    --text-color: #1f2937;
    --background-color: #ffffff;
    --accent-color: #f59e0b;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-600: #4b5563;
    --gray-800: #1f2937;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
}

/* 导航栏 */
.header {
    background: var(--background-color);
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
}

.nav {
    padding: 1rem 0;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 2rem;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.nav-logo h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    margin: 0;
}

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

.nav-menu a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

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

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width 0.3s ease;
}

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

/* 英雄区域 */
.hero {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 8rem 0 4rem;
    text-align: center;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><defs><pattern id="grid" width="10" height="10" patternUnits="userSpaceOnUse"><path d="M 10 0 L 0 0 0 10" fill="none" stroke="rgba(255,255,255,0.1)" stroke-width="0.5"/></pattern></defs><rect width="100" height="100" fill="url(%23grid)"/></svg>');
    opacity: 0.3;
}

.hero-container {
    position: relative;
    z-index: 1;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.25rem;
    opacity: 0.9;
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.hero-domain {
    margin-bottom: 3rem;
}

.domain-badge {
    display: inline-block;
    background: rgba(255, 255, 255, 0.2);
    color: white;
    padding: 0.5rem 1rem;
    border-radius: 20px;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    border: 1px solid rgba(255, 255, 255, 0.3);
    backdrop-filter: blur(10px);
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 3rem;
    flex-wrap: wrap;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--accent-color);
}

.stat-label {
    font-size: 0.9rem;
    opacity: 0.8;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* 通用容器 */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

.section {
    padding: 5rem 0;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 3rem;
    color: var(--text-color);
    font-weight: 700;
}

/* 项目概述 */
.overview-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.overview-card {
    background: white;
    padding: 2.5rem;
    border-radius: 16px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    text-align: center;
    transition: all 0.3s ease;
    border: 1px solid var(--gray-200);
}

.overview-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 25px rgba(0,0,0,0.1);
    border-color: var(--primary-color);
}

.card-icon {
    font-size: 3.5rem;
    margin-bottom: 1.5rem;
}

.overview-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.overview-card p {
    color: var(--gray-600);
    line-height: 1.6;
}

/* 研究成果 */
.research-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 3rem;
    align-items: start;
}

.research-item {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    border: 1px solid var(--gray-200);
}

.research-item h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

.research-item ul {
    list-style: none;
    padding: 0;
}

.research-item li {
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--gray-200);
    position: relative;
    padding-left: 1.5rem;
}

.research-item li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

.parameter-grid {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.parameter {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    background: var(--gray-100);
    border-radius: 8px;
}

.param-name {
    font-weight: 500;
    color: var(--text-color);
}

.param-value {
    font-weight: 600;
    color: var(--primary-color);
    background: white;
    padding: 0.25rem 0.75rem;
    border-radius: 6px;
    border: 1px solid var(--gray-200);
}

/* 智能体系统 */
.agents-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
    gap: 2rem;
}

.agent-card {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    border: 1px solid var(--gray-200);
    transition: transform 0.3s ease;
}

.agent-card:hover {
    transform: translateY(-5px);
}

.agent-header {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    padding: 2rem;
    text-align: center;
}

.agent-icon {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.agent-header h3 {
    font-size: 1.5rem;
    font-weight: 600;
}

.agent-content {
    padding: 2rem;
}

.agent-content p {
    margin-bottom: 1rem;
    color: var(--gray-600);
}

.agent-content ul {
    list-style: none;
    padding: 0;
}

.agent-content li {
    padding: 0.5rem 0;
    border-bottom: 1px solid var(--gray-200);
    position: relative;
    padding-left: 1.5rem;
}

.agent-content li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: bold;
}

/* 文档下载 */
.documents-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.document-card {
    background: white;
    padding: 2.5rem;
    border-radius: 16px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    text-align: center;
    border: 1px solid var(--gray-200);
    transition: all 0.3s ease;
}

.document-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 25px rgba(0,0,0,0.1);
}

.doc-icon {
    font-size: 3rem;
    margin-bottom: 1.5rem;
}

.document-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.document-card p {
    color: var(--gray-600);
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.btn-download {
    display: inline-block;
    background: var(--primary-color);
    color: white;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    border: 2px solid var(--primary-color);
}

.btn-download:hover {
    background: var(--secondary-color);
    border-color: var(--secondary-color);
    transform: translateY(-2px);
}

/* 联系我们 */
.contact-content {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.contact-content p {
    font-size: 1.1rem;
    color: var(--gray-600);
    margin-bottom: 2rem;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.contact-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem;
    background: var(--gray-100);
    border-radius: 8px;
    text-align: left;
}

.contact-label {
    font-weight: 600;
    color: var(--text-color);
}

.contact-value {
    color: var(--gray-600);
}

/* 页脚 */
.footer {
    background: var(--gray-800);
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 4rem;
}

.footer a {
    color: #60a5fa;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer a:hover {
    color: #93c5fd;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-stats {
        gap: 2rem;
    }
    
    .research-grid {
        grid-template-columns: 1fr;
    }
    
    .agents-container {
        grid-template-columns: 1fr;
    }
    
    .contact-item {
        flex-direction: column;
        text-align: center;
        gap: 0.5rem;
    }
    
    .section {
        padding: 3rem 0;
    }
    
    .section-title {
        font-size: 2rem;
    }
    
    .domain-badge {
        font-size: 0.8rem;
        padding: 0.4rem 0.8rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 1rem;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .overview-card,
    .document-card {
        padding: 1.5rem;
    }
    
    .domain-badge {
        font-size: 0.7rem;
        padding: 0.3rem 0.6rem;
    }
}