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

:root {
    --primary-blue: #1e3c72;
    --primary-purple: #6a2c91;
    --secondary-blue: #2a5298;
    --accent-color: #00d4ff;
    --light-bg: #f5f7fa;
    --dark-text: #333;
    --light-text: #666;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: var(--dark-text);
    line-height: 1.6;
    background-color: #fff;
}

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

/* 英雄部分 */
.hero {
    position: relative;
    height: 40vh;
    min-height: 320px;
    max-height: 460px;
    overflow: hidden;
    background: linear-gradient(135deg, var(--primary-blue) 0%, var(--primary-purple) 100%);
}

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

.hero-slide {
    display: none;
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
}

.hero-slide.active {
    display: flex;
    align-items: center;
    animation: slideIn 0.5s ease-in;
}

@keyframes slideIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

.hero-slide img {
    position: absolute;
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0.26;
}

.hero-content {
    position: relative;
    z-index: 2;
    color: white;
    padding-left: 60px;
    max-width: 600px;
}

.hero-content h1 {
    font-size: 2.45rem;
    font-weight: bold;
    margin-bottom: 20px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
}

.hero-content p {
    font-size: 1.3rem;
    margin-bottom: 30px;
    opacity: 0.95;
}

/* 按钮样式 */
.btn-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--accent-color) 0%, #00a8cc 100%);
    color: white;
    border: none;
    padding: 12px 30px;
    font-size: 1rem;
    border-radius: 5px;
    cursor: pointer;
    transition: transform 0.3s, box-shadow 0.3s;
    text-decoration: none;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 16px rgba(0, 212, 255, 0.3);
}

/* 轮播控件 */
.carousel-controls {
    position: absolute;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%);
    z-index: 3;
    display: flex;
    gap: 10px;
}

.carousel-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.5);
    border: none;
    cursor: pointer;
    transition: all 0.3s;
}

.carousel-dot.active {
    background: white;
    width: 30px;
    border-radius: 6px;
}

/* 产品预览部分 */
.products-preview {
    padding: 80px 0;
    background-color: var(--light-bg);
}

.products-preview h2 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 50px;
    color: var(--primary-blue);
}

.preview-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.preview-card {
    background: white;
    padding: 22px;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.08);
    transition: all 0.3s;
    border-top: 4px solid var(--primary-purple);
}

.preview-image {
    width: 100%;
    height: 150px;
    object-fit: contain;
    background: #f7f9fc;
    border-radius: 8px;
    margin-bottom: 18px;
}

.preview-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.12);
}

.preview-card h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: var(--primary-blue);
}

.preview-card p {
    color: var(--light-text);
    margin-bottom: 20px;
    font-size: 0.95rem;
}

.card-link {
    color: var(--accent-color);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.3s;
}

.card-link:hover {
    color: #00a8cc;
}

/* 学术与动态部分 */
.academic-news {
    padding: 80px 0;
    background: white;
}

.section-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
}

.section-col h2 {
    font-size: 2rem;
    margin-bottom: 30px;
    color: var(--primary-purple);
    border-bottom: 3px solid var(--accent-color);
    padding-bottom: 15px;
}

.news-list {
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.news-item {
    padding: 20px;
    border-left: 4px solid var(--primary-blue);
    background: var(--light-bg);
    border-radius: 5px;
    transition: all 0.3s;
}

.news-item:hover {
    background: #e8f1ff;
    transform: translateX(10px);
}

.news-item h4 {
    margin-bottom: 8px;
    color: var(--primary-blue);
}

.news-item p {
    font-size: 0.9rem;
    color: var(--light-text);
    margin-bottom: 10px;
}

.read-more {
    color: var(--accent-color);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.3s;
}

.read-more:hover {
    color: #00a8cc;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .hero-content h1 {
        font-size: 2rem;
    }

    .hero-content p {
        font-size: 1rem;
    }

    .products-preview h2 {
        font-size: 2rem;
    }

    .section-row {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .preview-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero {
        height: 400px;
    }

    .hero-content {
        padding-left: 20px;
    }

    .hero-content h1 {
        font-size: 1.5rem;
    }

    .hero-content p {
        font-size: 0.9rem;
    }
}



.home-video-section {
    background: #f8fafc;
    padding: 42px 20px;
    border-bottom: 1px solid #e5ebf3;
}

.home-video-layout {
    display: grid;
    grid-template-columns: minmax(260px, 0.75fr) 1.25fr;
    gap: 28px;
    align-items: center;
}

.home-video-copy h2 {
    color: var(--primary-blue);
    font-size: 1.75rem;
    margin-bottom: 12px;
}

.home-video-copy p {
    color: #34405a;
    line-height: 1.8;
    margin-bottom: 12px;
}

.section-kicker {
    display: inline-block;
    color: var(--accent-color);
    font-weight: 700;
    margin-bottom: 8px;
    font-size: 0.9rem;
}

.home-video-layout video {
    width: 100%;
    aspect-ratio: 16 / 9;
    display: block;
    background: #0f172a;
    border-radius: 8px;
    box-shadow: 0 14px 30px rgba(16, 41, 79, 0.16);
}

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