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

body {
    font-family: 'Poppins', 'Microsoft YaHei', '微软雅黑', 'SimSun', '宋体', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    color: #333;
    line-height: 1.6;
    overflow-x: hidden;
}

/* 启动页样式 */
.splash-screen {
    background: #f8f9fa;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background: #000;
    z-index: 9999;
    cursor: pointer;
    transition: opacity 0.8s ease-out;
    display: none; /* 默认隐藏 */
    align-items: center;
    justify-content: center;
}

.splash-content {
    width: 100%;
    height: 100%;
    position: relative;
    overflow: hidden;
}

.image-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    grid-template-rows: repeat(2, 1fr);
    width: 100%;
    height: 100%;
    gap: 2px;
    background: #000;
}

.grid-item {
    position: relative;
    overflow: hidden;
    background-size: cover;
    background-position: center;
    transition: transform 0.5s ease;
    filter: brightness(0.7);
}

.grid-item:hover {
    transform: scale(1.05);
    filter: brightness(0.9);
}

.watermark {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 15vw;
    font-weight: 700;
    color: rgba(255, 255, 255, 0.1);
    text-transform: uppercase;
    letter-spacing: 0.2em;
    user-select: none;
    pointer-events: none;
}

.click-hint {
    position: absolute;
    bottom: 50px;
    left: 50%;
    transform: translateX(-50%);
    color: #fff;
    font-size: 18px;
    opacity: 0.8;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 0.8; }
    50% { opacity: 0.3; }
}

/* 主内容样式 */
.main-content {
    opacity: 1;
    transition: opacity 0.8s ease-in;
}

.main-content.hidden {
    display: none;
}

/* 导航栏样式 */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.1);
    z-index: 1000;
    padding: 1rem 0;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 28px;
    font-weight: 700;
    font-family: 'Poppins', 'Microsoft YaHei', '微软雅黑', sans-serif;
    color: #2c3e50;
    text-decoration: none;
    letter-spacing: 0.05em;
}

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

.nav-link {
    text-decoration: none;
    color: #555;
    font-weight: 500;
    font-size: 1rem;
    font-family: 'Poppins', 'Microsoft YaHei', '微软雅黑', sans-serif;
    transition: color 0.3s ease;
    position: relative;
    padding: 5px 0;
}

.nav-link:hover {
    color: #3498db;
}

.nav-link.active {
    color: #3498db;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: #3498db;
    transition: width 0.3s ease;
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

/* 轮播图样式 */
.carousel {
    position: relative;
    width: 100%;
    height: 600px;
    overflow: hidden;
    margin-top: 70px;
}

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

.carousel-slide {
    position: absolute;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 1s ease-in-out;
}

.carousel-slide.active {
    opacity: 1;
}

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

.carousel-caption {
    position: absolute;
    bottom: 50px;
    left: 50%;
    transform: translateX(-50%);
    text-align: center;
    color: white;
    background: rgba(0, 0, 0, 0.5);
    padding: 30px 50px;
    border-radius: 10px;
    backdrop-filter: blur(5px);
}

.carousel-caption h2 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

.carousel-caption p {
    font-size: 1.2rem;
}

.carousel-controls button {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(255, 255, 255, 0.2);
    border: none;
    color: white;
    font-size: 3rem;
    padding: 10px 20px;
    cursor: pointer;
    transition: background 0.3s ease;
}

.carousel-controls button:hover {
    background: rgba(255, 255, 255, 0.3);
}

.carousel-prev {
    left: 20px;
}

.carousel-next {
    right: 20px;
}

.carousel-indicators {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 10px;
}

.indicator {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.5);
    cursor: pointer;
    transition: background 0.3s ease;
}

.indicator.active {
    background: white;
}

/* Hero Section */
.hero-section {
    text-align: center;
    padding: 80px 20px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.hero-section h1 {
    font-size: 3rem;
    margin-bottom: 20px;
    animation: fadeInUp 1s ease-out;
}

.lead {
    font-size: 1.5rem;
    opacity: 0.9;
    animation: fadeInUp 1s ease-out 0.2s both;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Features Section */
.features {
    padding: 80px 20px;
    background: #f8f9fa;
}

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

.section-title {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 50px;
    color: #2c3e50;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
}

.feature-card {
    background: white;
    padding: 40px 30px;
    border-radius: 10px;
    text-align: center;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
}

.feature-icon {
    font-size: 3rem;
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: #2c3e50;
}

.feature-card p {
    color: #666;
    line-height: 1.8;
}

/* Footer */
.footer {
    background: #2c3e50;
    color: white;
    text-align: center;
    padding: 30px 20px;
    margin-top: 80px;
}

.footer a {
    color: #bdc3c7;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer a:hover {
    color: #ecf0f1;
    text-decoration: none;
}

/* 胡剑浩教授链接样式 */
.hero-section .link-button {
    background: none;
    color: #ecf0f1;
    padding: 0;
    border-radius: 0;
    text-decoration: none;
    font-size: inherit;
    transition: color 0.3s ease;
    border-bottom: 1px solid rgba(236, 240, 241, 0.3);
}

.hero-section .link-button:hover {
    background: none;
    color: #fff;
    border-bottom-color: rgba(255, 255, 255, 0.8);
}

/* 分割背景样式 */
.split-background {
    position: relative;
    width: 100%;
    height: 100%;
    overflow: hidden;
}

.left-half, .right-half {
    position: absolute;
    top: 0;
    width: 50%;
    height: 100%;
    background-size: cover;
    background-position: center;
    transition: all 0.8s ease;
}

.left-half {
    left: 0;
    background-image: var(--left-bg);
}

.right-half {
    right: 0;
    background-image: var(--right-bg);
}

/* 渐变叠加层 */
.overlay-gradient {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(
        135deg,
        rgba(102, 126, 234, 0.3) 0%,
        rgba(118, 75, 162, 0.3) 50%,
        rgba(0, 0, 0, 0.2) 100%
    );
    z-index: 1;
}

/* 几何图案装饰 */
.geometric-pattern {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        radial-gradient(circle at 20% 80%, rgba(255, 255, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 20%, rgba(255, 255, 255, 0.1) 0%, transparent 50%),
        linear-gradient(45deg, transparent 40%, rgba(255, 255, 255, 0.05) 50%, transparent 60%);
    z-index: 2;
    animation: patternFloat 20s ease-in-out infinite;
}

@keyframes patternFloat {
    0%, 100% { transform: translateY(0px) rotate(0deg); }
    50% { transform: translateY(-10px) rotate(1deg); }
}

/* 现代化标题样式 */
.modern-caption {
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 20px;
    padding: 40px 60px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
    z-index: 3;
    position: relative;
    overflow: hidden;
}

.modern-caption::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(45deg, transparent 30%, rgba(255, 255, 255, 0.05) 50%, transparent 70%);
    animation: shimmer 3s ease-in-out infinite;
}

@keyframes shimmer {
    0%, 100% { transform: translateX(-100%); }
    50% { transform: translateX(100%); }
}

.modern-caption h2 {
    font-size: 2.8rem;
    margin-bottom: 15px;
    background: linear-gradient(45deg, #fff, #e0e7ff);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    position: relative;
    z-index: 2;
}

.modern-caption p {
    font-size: 1.3rem;
    line-height: 1.6;
    color: rgba(255, 255, 255, 0.9);
    position: relative;
    z-index: 2;
}

/* 标题装饰元素 */
.caption-decoration {
    position: absolute;
    bottom: -2px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, #667eea, #764ba2);
    border-radius: 2px;
    z-index: 2;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .image-grid {
        grid-template-columns: 1fr;
        grid-template-rows: repeat(4, 1fr);
    }
    
    .watermark {
        font-size: 25vw;
    }
    
    .nav-menu {
        flex-direction: column;
        gap: 1rem;
    }
    
    .carousel {
        height: 400px;
    }
    
    .carousel-caption h2 {
        font-size: 1.5rem;
    }
    
    .carousel-caption p {
        font-size: 1rem;
    }
    
    .hero-section h1 {
        font-size: 2rem;
    }
    
    .lead {
        font-size: 1.2rem;
    }

    .left-half, .right-half {
        width: 100%;
        opacity: 0.8;
    }
    
    .right-half {
        left: 0;
        right: auto;
    }
    
    .modern-caption {
        padding: 30px 40px;
        margin: 0 20px;
    }
    
    .modern-caption h2 {
        font-size: 2rem;
    }
    
    .modern-caption p {
        font-size: 1.1rem;
    }
}

/* 超小屏幕优化 */
@media (max-width: 480px) {
    .carousel {
        height: 300px;
    }
    
    .carousel-caption {
        padding: 20px 30px;
        bottom: 30px;
    }
    
    .carousel-caption h2 {
        font-size: 1.2rem;
        margin-bottom: 8px;
    }
    
    .carousel-caption p {
        font-size: 0.9rem;
        line-height: 1.4;
    }
    
    .modern-caption {
        padding: 20px 25px;
        margin: 0 15px;
    }
    
    .modern-caption h2 {
        font-size: 1.4rem;
    }
    
    .modern-caption p {
        font-size: 0.95rem;
    }
    
    .hero-section h1 {
        font-size: 1.8rem;
    }
    
    .lead {
        font-size: 1.1rem;
    }
}

/* 页面切换动画 */
.fade-in {
    animation: fadeIn 0.8s ease-in;
}

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