/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Arial', sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
}

/* 头部样式 */
header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 1rem 0;
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

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

.logo h1 {
    font-size: 1.8rem;
    font-weight: bold;
}

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

.nav-links a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: opacity 0.3s ease;
}

.nav-links a:hover {
    opacity: 0.8;
}

/* 主要内容区域 */
main {
    margin-top: 80px;
}

/* 英雄区域 */
.hero {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 4rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
    min-height: 80vh;
}

.hero-content {
    flex: 1;
    max-width: 600px;
}

.hero-content h2 {
    font-size: 3rem;
    color: #2c3e50;
    margin-bottom: 1rem;
    font-weight: bold;
}

.hero-content p {
    font-size: 1.2rem;
    color: #555;
    margin-bottom: 2rem;
    line-height: 1.8;
}

.cta-button {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 1rem 2rem;
    font-size: 1.1rem;
    border-radius: 50px;
    cursor: pointer;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.cta-button:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(102, 126, 234, 0.3);
}

/* 大脑动画 */
.hero-image {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

.brain-animation {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    justify-content: center;
    align-items: center;
    animation: pulse 2s infinite;
}

.brain-icon {
    font-size: 4rem;
    animation: rotate 4s linear infinite;
}

@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* 关于部分 */
.about-section {
    padding: 4rem 2rem;
    background: white;
}

.about-section h2 {
    text-align: center;
    font-size: 2.5rem;
    color: #2c3e50;
    margin-bottom: 3rem;
}

.about-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    max-width: 1200px;
    margin: 0 auto;
    gap: 3rem;
}

.about-text {
    flex: 1;
}

.about-text p {
    font-size: 1.1rem;
    color: #555;
    margin-bottom: 1.5rem;
    line-height: 1.8;
}

.about-text ul {
    list-style: none;
    padding-left: 0;
}

.about-text li {
    font-size: 1.1rem;
    color: #555;
    margin-bottom: 0.8rem;
    padding-left: 1.5rem;
    position: relative;
}

.about-text li::before {
    content: "▸";
    color: #667eea;
    position: absolute;
    left: 0;
    font-weight: bold;
}

.about-image {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
}

.neuron-diagram {
    position: relative;
    width: 200px;
    height: 200px;
}

.neuron {
    font-size: 3rem;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.synapse {
    font-size: 2rem;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    animation: synapse-pulse 1.5s infinite;
}

@keyframes synapse-pulse {
    0%, 100% { opacity: 0.3; }
    50% { opacity: 1; }
}

/* 研究部分 */
.research-section {
    padding: 4rem 2rem;
    background: #f8f9fa;
}

.research-section h2 {
    text-align: center;
    font-size: 2.5rem;
    color: #2c3e50;
    margin-bottom: 3rem;
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.research-card {
    background: white;
    padding: 2rem;
    border-radius: 15px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    text-align: center;
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.research-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 30px rgba(0,0,0,0.15);
}

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

.research-card h3 {
    font-size: 1.5rem;
    color: #2c3e50;
    margin-bottom: 1rem;
}

.research-card p {
    color: #555;
    line-height: 1.6;
}

/* 应用部分 */
.applications-section {
    padding: 4rem 2rem;
    background: white;
}

.applications-section h2 {
    text-align: center;
    font-size: 2.5rem;
    color: #2c3e50;
    margin-bottom: 3rem;
}

.applications-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.application-item {
    padding: 2rem;
    background: #f8f9fa;
    border-radius: 15px;
    border-left: 5px solid #667eea;
}

.application-item h3 {
    font-size: 1.3rem;
    color: #2c3e50;
    margin-bottom: 1rem;
}

.application-item p {
    color: #555;
    line-height: 1.6;
}

/* 联系部分 */
.contact-section {
    padding: 4rem 2rem;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-align: center;
}

.contact-section h2 {
    font-size: 2.5rem;
    margin-bottom: 2rem;
}

.contact-content p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.contact-info p {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

/* 页脚 */
footer {
    background: #2c3e50;
    color: white;
    text-align: center;
    padding: 2rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .hero {
        flex-direction: column;
        text-align: center;
    }
    
    .hero-content h2 {
        font-size: 2.5rem;
    }
    
    .about-content {
        flex-direction: column;
    }
    
    .research-grid {
        grid-template-columns: 1fr;
    }
    
    .applications-content {
        grid-template-columns: 1fr;
    }
}

/* 平滑滚动 */
html {
    scroll-behavior: smooth;
}

/* 加载动画 */
.loading {
    opacity: 0;
    animation: fadeIn 1s ease-in-out forwards;
}

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