:root {
    --primary-blue: #1e88e5;
    --secondary-blue: #90caf9;
    --light-blue: #e3f2fd;
    --dark-blue: #0d47a1;
    --gold: #d4af37;
    --white: #ffffff;
    --dark-text: #333333;
    --light-text: #666666;
}

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

body {
    font-family: 'Noto Serif SC', 'Microsoft YaHei', serif;
    background-color: #f8fbff;
    color: var(--dark-text);
    line-height: 1.6;
}

#wrapper {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    position: relative;
    z-index: 2;
}

/* 页面标题区域 */
.page-header {
    text-align: center;
    padding: 30px 20px;
    background: linear-gradient(135deg, var(--primary-blue), var(--dark-blue));
    color: var(--white);
    border-radius: 15px;
    margin-bottom: 30px;
    box-shadow: 0 10px 30px rgba(13, 71, 161, 0.2);
}

.page-title {
    font-size: 2.5rem;
    margin-bottom: 10px;
    font-weight: 600;
    letter-spacing: 2px;
}

.page-subtitle {
    font-size: 1.2rem;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto;
}

/* Logo样式 */
.logo {
    text-align: center;
    padding: 20px 0;
}

.logo img {
    max-width: 180px;
    height: auto;
    filter: drop-shadow(0 5px 15px rgba(0, 0, 0, 0.2));
}

/* 视频容器 */
.video-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    padding: 20px 0 40px;
}

.video-item {
    position: relative;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    background: var(--white);
}

.video-item:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 30px rgba(30, 136, 229, 0.25);
}

video {
    width: 100%;
    height: auto;
    display: block;
    border-radius: 12px 12px 0 0;
}

.video-info {
    padding: 15px;
    background: var(--white);
    border-radius: 0 0 12px 12px;
    border-top: 3px solid var(--primary-blue);
}

.video-title {
    font-size: 1.1rem;
    color: var(--dark-blue);
    margin-bottom: 8px;
    font-weight: 500;
}

.video-desc {
    color: var(--light-text);
    font-size: 0.9rem;
}

/* 返回按钮 */
.btn-back {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    margin: 20px auto;
    padding: 12px 30px;
    background: linear-gradient(135deg, var(--primary-blue), var(--dark-blue));
    color: var(--white);
    text-decoration: none;
    border-radius: 30px;
    font-size: 1.1rem;
    font-weight: 500;
    transition: all 0.3s ease;
    box-shadow: 0 5px 15px rgba(30, 136, 229, 0.3);
    border: 2px solid rgba(255, 255, 255, 0.3);
}

.btn-back:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 20px rgba(30, 136, 229, 0.4);
}

.btn-back i {
    margin-right: 8px;
}

/* 背景 */
#bg {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background: linear-gradient(120deg, var(--light-blue), #bbdefb);
    opacity: 0.7;
}

/* 装饰元素 */
.decoration {
    position: absolute;
    z-index: -1;
    opacity: 0.1;
    color: var(--primary-blue);
}

.decoration-1 {
    top: 10%;
    left: 5%;
    font-size: 5rem;
}

.decoration-2 {
    bottom: 10%;
    right: 5%;
    font-size: 5rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .page-title {
        font-size: 2rem;
    }
    
    .page-subtitle {
        font-size: 1rem;
    }
    
    .video-container {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .btn-back {
        width: 100%;
        max-width: 300px;
        padding: 10px 20px;
    }
    
    .decoration {
        display: none;
    }
}

@media (min-width: 769px) and (max-width: 1024px) {
    .video-container {
        grid-template-columns: repeat(2, 1fr);
    }
}