/* 使用自定义字体 */
body {
    font-family: 'Noto Sans SC', sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f5f5f5;
    color: #333;
    line-height: 1.6;
}

header {
    background: linear-gradient(135deg, #3498db, #2ecc71);
    color: white;
    text-align: center;
    padding: 2rem 0;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.container {
    width: 90%;
    max-width: 1200px;
    margin: 2rem auto;
}

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

.video-card {
    background: white;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.video-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.video-thumbnail {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.video-info {
    padding: 1.5rem;
}

.video-title {
    margin-top: 0;
    color: #2c3e50;
}

.video-description {
    color: #7f8c8d;
    margin-bottom: 1.5rem;
}

.btn {
    display: inline-block;
    background: linear-gradient(135deg, #3498db, #2ecc71);
    color: white;
    padding: 0.8rem 1.5rem;
    border-radius: 50px;
    text-decoration: none;
    transition: background 0.3s ease;
}

.btn:hover {
    background: linear-gradient(135deg, #2980b9, #27ae60);
}

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.modal-content {
    background: white;
    border-radius: 10px;
    width: 90%;
    max-width: 800px;
    position: relative;
    padding: 1rem;
}

.close-btn {
    position: absolute;
    top: 10px;
    right: 20px;
    font-size: 2rem;
    color: #7f8c8d;
    cursor: pointer;
    transition: color 0.3s ease;
}

.close-btn:hover {
    color: #e74c3c;
}

.video-player {
    width: 100%;
    border-radius: 5px;
}