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

:root {
    --primary-color: #007bff;
    --primary-dark: #0056b3;
    --primary-light: #e3f2fd;
    --text-color: #333;
    --text-light: #666;
    --bg-color: #f9f9f9;
    --white: #ffffff;
    --border-color: #e0e0e0;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 16px rgba(0, 0, 0, 0.1);
    --border-radius: 8px;
    --transition: all 0.3s ease;
}

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

/* 容器样式 */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* 导航栏样式 */
.site-header {
    background: var(--white);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 1000;
    margin-bottom: 2px;
}

.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 0;
}

.navbar-brand .brand-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    transition: var(--transition);
}

.navbar-brand .brand-logo:hover {
    color: var(--primary-dark);
}

.navbar-brand .brand-logo svg {
    width: 32px;
    height: 32px;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 1.5rem;
}

.nav-item .nav-link {
    color: var(--text-color);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
    position: relative;
    padding: 0.5rem 0;
}

.nav-item .nav-link:hover {
    color: var(--primary-color);
}

.nav-item .nav-link.active {
    color: var(--primary-color);
}

.nav-item .nav-link.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background: var(--primary-color);
    border-radius: 2px;
}

.navbar-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.navbar-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-color);
    transition: var(--transition);
}

/* 英雄区域样式 */
.hero-section {
    position: relative;
    overflow: hidden;
    height: 500px;
    display: flex;
    align-items: center;
}

.hero-slider {
    position: relative;
    width: 100%;
    height: 100%;
}

.slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    display: flex;
    align-items: center;
}

.slide.active {
    opacity: 1;
    visibility: visible;
    position: relative;
}

.slide-content {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    z-index: 2;
    max-width: 600px;
    padding: 2rem;
    color: var(--white);
    text-align: center;
    margin: 0 auto;
}

.slide-content h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    text-shadow: 0 2px 4px rgba(0, 0, 0, 0.5);
}

.slide-content p {
    font-size: 1.2rem;
    margin-bottom: 2rem;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.5);
}

.slide-bg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1;
}

.slide-bg img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.slide-bg::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
}

.slider-controls {
    position: absolute;
    top: 50%;
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-between;
    transform: translateY(-50%);
    padding: 0 2rem;
    z-index: 3;
}

.slider-controls button {
    background: rgba(255, 255, 255, 0.2);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition);
    color: var(--white);
}

.slider-controls button:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1);
}

.slider-indicators {
    position: absolute;
    bottom: 2rem;
    left: 0;
    right: 0;
    display: flex;
    justify-content: center;
    gap: 10px;
    z-index: 3;
}

.slider-indicators button {
    width: 12px;
    height: 12px;
    border: 2px solid rgba(255, 255, 255, 0.5);
    border-radius: 50%;
    background: transparent;
    cursor: pointer;
    transition: var(--transition);
}

.slider-indicators button.active {
    background: var(--white);
    transform: scale(1.2);
}

/* 特色区域样式 */
.features-section {
    padding: 4rem 0;
    background: var(--white);
}

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

.section-title::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    background: var(--primary-color);
    border-radius: 2px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: var(--white);
    border-radius: var(--border-radius);
    padding: 2rem;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.feature-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-5px);
}

.feature-icon {
    width: 80px;
    height: 80px;
    background: var(--primary-light);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    color: var(--primary-color);
    transition: var(--transition);
}

.feature-card:hover .feature-icon {
    background: var(--primary-color);
    color: var(--white);
}

.feature-card h3 {
    font-size: 1.3rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.feature-card p {
    color: var(--text-light);
    line-height: 1.6;
}

/* 实验项目区域样式 */
.experiments-section {
    padding: 20px 0 4rem;
    background: var(--bg-color);
}



.experiments-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
}

.experiment-card {
    background: var(--white);
    border-radius: var(--border-radius);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.experiment-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-5px);
}

.card-inner {
    padding: 2rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.card-icon {
    width: 80px;
    height: 80px;
    background: var(--primary-light);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
    color: var(--primary-color);
    transition: var(--transition);
}

.experiment-card:hover .card-icon {
    background: var(--primary-color);
    color: var(--white);
}

.card-inner h3 {
    font-size: 1.2rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.btn-primary {
    padding: 0.8rem 2rem;
    background: var(--primary-color);
    color: var(--white);
    text-decoration: none;
    border-radius: var(--border-radius);
    font-weight: 500;
    transition: var(--transition);
    align-self: stretch;
    text-align: center;
    border: none;
    cursor: pointer;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.no-experiments {
    grid-column: 1 / -1;
    text-align: center;
    padding: 4rem;
    color: var(--text-light);
    background: var(--white);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
}

/* 页脚样式 */
.site-footer {
    background: var(--white);
    padding: 3rem 0 1rem;
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-info h3 {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.footer-info p {
    color: var(--text-light);
    margin-bottom: 1rem;
    line-height: 1.6;
}

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

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

.contact-info a:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

.footer-links h4 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-color);
    margin-bottom: 1rem;
}

.footer-links ul {
    list-style: none;
}

.footer-links li {
    margin-bottom: 0.5rem;
}

.footer-links a {
    color: var(--text-light);
    text-decoration: none;
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--primary-color);
    padding-left: 5px;
}

.footer-bottom {
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--text-light);
}

.footer-bottom p {
    margin-bottom: 0.5rem;
}

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

.footer-bottom a:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

/* 响应式设计 */
@media (max-width: 992px) {
    .slide-content h1 {
        font-size: 2.5rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
}

@media (max-width: 768px) {
    .navbar-menu {
        position: fixed;
        top: 70px;
        left: 0;
        right: 0;
        background: var(--white);
        padding: 1rem 0;
        box-shadow: var(--shadow-sm);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
        z-index: 999;
    }
    
    .navbar-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .nav-links {
        flex-direction: column;
        align-items: center;
        gap: 1rem;
    }
    
    .navbar-toggle {
        display: flex;
    }
    
    .navbar-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }
    
    .navbar-toggle.active span:nth-child(2) {
        opacity: 0;
    }
    
    .navbar-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(5px, -5px);
    }
    
    .slide-content {
        padding: 1.5rem;
    }
    
    .slide-content h1 {
        font-size: 2rem;
    }
    
    .slide-content p {
        font-size: 1rem;
    }
    
    .slider-controls {
        padding: 0 1rem;
    }
    
    .slider-controls button {
        width: 40px;
        height: 40px;
    }
    
    .features-section,
    .experiments-section {
        padding: 3rem 0;
    }
}

@media (max-width: 576px) {
    .navbar-brand .brand-logo {
        font-size: 1.2rem;
    }
    
    .navbar-brand .brand-logo svg {
        width: 24px;
        height: 24px;
    }
    
    .hero-section {
        min-height: 60vh;
    }
    
    .slide-content h1 {
        font-size: 1.8rem;
    }
    
    .section-title {
        font-size: 1.8rem;
    }
    
    .feature-card,
    .experiment-card {
        padding: 1.5rem;
    }
    
    .search-box {
        flex-direction: column;
    }
    
    .search-box button {
        justify-content: center;
    }
    
    .footer-content {
        gap: 1.5rem;
    }
}