/* ================= 授课视频页面样式 ================= */
.videos-page {
    padding-top: 130px;
    padding-bottom: 80px;
    min-height: 100vh;
    max-width: 1400px;
    margin: 0 auto;
    padding-left: 40px;
    padding-right: 40px;
}

.page-header {
    text-align: center;
    margin-bottom: 60px;
}

.page-title {
    font-size: 3.2rem;
    font-weight: 900;
    margin-bottom: 18px;
    background: linear-gradient(135deg, #ffffff 0%, #cbd5e1 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.5px;
}

.page-subtitle {
    color: var(--text-muted);
    font-size: 1.15rem;
    max-width: 650px;
    margin: 0 auto;
    line-height: 1.7;
}

.videos-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(420px, 1fr));
    gap: 35px;
}

/* Video Card 质感升级 */
.video-card {
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    backdrop-filter: blur(20px);
    display: flex;
    flex-direction: column;
    box-shadow: 0 4px 24px rgba(0,0,0,0.2);
    position: relative;
}

.video-card:hover {
    transform: translateY(-8px);
    background: rgba(255, 255, 255, 0.04);
    border-color: var(--glass-border-hover);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3), 0 0 30px rgba(196, 113, 237, 0.15);
}

.video-card video {
    width: 100%;
    aspect-ratio: 16 / 9;
    background: #000;
    outline: none;
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

.video-locked-preview {
    width: 100%;
    aspect-ratio: 16 / 9;
    background: linear-gradient(135deg, rgba(15, 23, 42, 0.95), rgba(20, 42, 64, 0.9));
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 12px;
    color: var(--text-muted);
    text-decoration: none;
    transition: color 0.25s ease, background 0.25s ease;
}

.video-locked-preview i {
    width: 58px;
    height: 58px;
    border-radius: 50%;
    display: grid;
    place-items: center;
    color: #fff;
    background: rgba(79, 172, 254, 0.18);
    border: 1px solid rgba(79, 172, 254, 0.28);
    font-size: 1.35rem;
}

.video-locked-preview span {
    font-weight: 700;
}

.video-locked-preview:hover {
    color: #fff;
    background: linear-gradient(135deg, rgba(20, 42, 64, 0.96), rgba(21, 77, 108, 0.92));
}

.video-info {
    padding: 24px;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
}

.video-info h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-main);
    margin: 0;
    transition: color 0.3s ease;
}

.video-info .file-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.video-info .file-meta span {
    display: flex;
    align-items: center;
    gap: 6px;
    background: rgba(255,255,255,0.05);
    padding: 4px 10px;
    border-radius: var(--radius-full);
}

.video-card:hover .video-info h3 {
    background: linear-gradient(135deg, var(--color-blue), var(--color-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

@media (max-width: 768px) {
    .videos-grid {
        grid-template-columns: 1fr;
    }
}