/* ===== show.php 专用样式 ===== */
/* 播放器区域 */
.player-video {
    position: relative;
    display: flex;
    justify-content: center;
    align-items: center;
    background: #000;
    border-radius: 8px;
    overflow: hidden;
    width: 100%;
    max-width: 100%;
}
.video-container {
    position: relative;
    width: 100%;
    aspect-ratio: 16 / 9;
}
.video-wrapper {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
}
.video-wrapper video {
    width: 100%;
    height: 100%;
    object-fit: contain;
    display: block;
}
.video-cover {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-size: cover;
    background-position: center;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    z-index: 10;
    transition: opacity 0.3s ease;
}
.video-cover.hidden {
    opacity: 0;
    pointer-events: none;
}
/* 播放按钮覆盖层 */
.video-cover::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(4px);
    display: flex;
    justify-content: center;
    align-items: center;
    transition: all 0.3s ease;
}
.video-cover:hover::after {
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%) scale(1.1);
}
.video-cover i {
    position: relative;
    z-index: 1;
    font-size: 36px;
    color: #fff;
    margin-left: 5px;
}
/* 相关课程网格 */
.related-lessons {
    margin-top: 32px;
    margin-bottom: 24px;
}
.course-grid-small {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}
.course-grid-small .course-card-small:nth-child(n+9) {
    display: none;
}
@media (min-width: 2000px) {
    .course-grid-small {
        grid-template-columns: repeat(5, 1fr);
    }
    .course-grid-small .course-card-small:nth-child(n+11) {
        display: none;
    }
    .course-grid-small .course-card-small:nth-child(n+9) {
        display: block;
    }
}
@media (max-width: 1300px) {
    .video-container {
        aspect-ratio: 16 / 9;
    }
    .video-cover {
        background-position: center center;
    }
    .course-grid-small {
        grid-template-columns: repeat(3, 1fr);
    }
    .course-grid-small .course-card-small:nth-child(n+7) {
        display: none;
    }
}
@media (max-width: 576px) {
    .course-grid-small {
        grid-template-columns: repeat(2, 1fr);
    }
    .course-grid-small .course-card-small:nth-child(n+5) {
        display: none;
    }
}
@media (max-width: 480px) {
    .video-container {
        aspect-ratio: 16 / 9;
    }
}
@media (max-width: 400px) {
    .course-grid-small {
        grid-template-columns: 1fr;
    }
    .course-grid-small .course-card-small:nth-child(n+3) {
        display: none;
    }
}