/* 变量定义 */
:root {
    --primary-color: #2E7D32;
    --text-main: #333;
    --text-sub: #666;
    --bg-light: #f9fafb;
}

/* 组件容器 */
.edu-video-card {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    max-width: 10240px;
    margin: 20px auto;
    background: #fff;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.1);
    overflow: hidden;
    border: 1px solid #eee;
}

/* 头部信息 */
.edu-header { padding: 20px 24px; border-bottom: 1px solid #eee; }
.edu-tag { display: inline-block; background: #e8f5e9; color: var(--primary-color); font-size: 12px; padding: 4px 8px; border-radius: 4px; margin-bottom: 8px; font-weight: 600; }
.edu-title { margin: 0; font-size: 18px; color: var(--primary-color); display: flex; align-items: center; gap: 8px; }
.edu-subtitle { margin: 10px 0 0; font-size: 20px; font-weight: bold; color: #333; line-height: 1.4; }

/* 视频区域 (16:9) */
.edu-video-wrap { position: relative; width: 100%; padding-bottom: 56.25%; background: #000; }
.edu-video-wrap video { position: absolute; top: 0; left: 0; width: 100%; height: 100%; object-fit: contain; }

/* 控制栏 */
.edu-controls {
    padding: 10px 24px 15px;
    display: flex;
    flex-direction: column;
    gap: 10px;
    background: #fff;
}
.edu-controls-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.edu-btn { background: none; border: none; cursor: pointer; color: var(--text-sub); padding: 8px; border-radius: 50%; transition: 0.2s; }
.edu-btn:hover { background: #f0f0f0; color: var(--primary-color); }
.edu-play-btn { background: var(--primary-color); color: #fff; width: 40px; height: 40px; display: flex; align-items: center; justify-content: center; }
.edu-play-btn:hover { background: #1b5e20; color: #fff; }
.edu-time { font-size: 13px; color: var(--text-sub); font-family: monospace; }

/* 进度条 */
.edu-progress {
    position: relative;
    width: 100%;
    height: 6px;
    background: #e0e0e0;
    border-radius: 3px;
    cursor: pointer;
    overflow: hidden;
}
.edu-progress-buffered {
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    background: #c8e6c9;
    border-radius: 3px;
    transition: width 0.3s ease;
}
.edu-progress-played {
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    background: var(--primary-color);
    border-radius: 3px;
    transition: width 0.1s linear;
}

/* 底部元数据 (居中) */
.edu-meta { padding: 15px 24px; background: #fafafa; border-top: 1px solid #eee; text-align: center; }
.edu-meta-list { display: flex; justify-content: center; flex-wrap: wrap; gap: 20px; font-size: 14px; color: var(--text-sub); }
.edu-meta-list strong { color: var(--text-main); }