body {
    margin: 0;
    padding: 0;
}
/* 横幅样式 */
.banners {
    background-color: #1e40af;
    color: #fff;
    text-align: center;
    padding: 50px 20px;
}

.banners h1 {
    margin: 0;
    font-size: 2.5em;
    margin-bottom: 10px;
}

.banners p {
    font-size: 1.2em;
}

/* 筛选条件样式 */
.filters {
    padding: 20px;
    background-color: #fff;
    margin: 20px auto;
    margin-left:0px;
    border-radius: 5px;
    box-shadow: 0 2px 5px rgba(0, 0, 0, 0.1);
    max-width: 1200px;
}

.filters label {
    margin-right: 10px;
    font-weight: 500;
}

.filters select {
    padding: 8px 12px;
    margin-right: 20px;
    border: 1px solid #ddd;
    border-radius: 4px;
    background-color: #fff;
    min-width: 120px;
}

/* 课程列表样式 */
.courses {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0px;
    text-align: center;
}

.courses h2 {
    margin-bottom: 30px;
    font-size: 1.8em;
    color: #333;
}

.course-list {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 20px;
}

.course-card {
    background-color: #fff;
    border-radius: 10px;
    overflow: hidden;
    width: 300px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    cursor: pointer;
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
}

.course-card .video-container {
    position: relative;
    width: 100%;
    height: 0;
    padding-bottom: 56.25%; /* 16:9 宽高比 */
    overflow: hidden;
}

/* 修改视频样式，使其适应不同方向的视频 */
.course-card video {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: contain; /* 改为contain以确保视频完全显示 */
    background-color: #000; /* 背景改为黑色，更适合视频播放 */
}

.course-info {
    padding: 15px;
    text-align: left;
}

.course-card h3 {
    margin: 0 0 10px 0;
    font-size: 1.2em;
    color: #333;
}

.course-card .instructor {
    font-weight: 500;
    color: #f77f18;
    margin-bottom: 5px;
}

.course-card .views {
    color: #888;
    font-size: 0.9em;
}
/* 视频加载错误提示 */
.video-error {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: #f8f8f8;
    color: #e74c3c;
    font-size: 0.9em;
    padding: 10px;
    text-align: center;
}

/* 视频加载中提示 */
.video-loading {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    background-color: #f8f8f8;
    color: #333;
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid rgba(247, 127, 24, 0.2);
    border-radius: 50%;
    border-top-color: #f77f18;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* 手册样式 */
.wenjian {
    max-width: 1200px;
    margin: 40px auto;
    padding: 0px;
    text-align: center;
}

.wenjian h2 {
    margin-bottom: 30px;
    font-size: 1.8em;
    color: #333;
}

.wenjian-list {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 30px;
}

.wenjian-card {
    background-color: #fff;
    border-radius: 10px;
    overflow: hidden;
    width: 180px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    cursor: pointer;
    text-decoration: none;
    color: inherit;
}

.wenjian-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
}


.wenjian-info {
    padding: 15px;
    text-align: left;
}

.wenjian-card h3 {
    margin: 0 0 10px 0;
    font-size: 1.2em;
    color: #333;
}

.wenjian-card .description {
    color: #666;
    font-size: 0.9em;
    margin-bottom: 10px;
}

.wenjian-card .date {
    color: #888;
    font-size: 0.8em;
}