/* --- 容器设置 --- */
.hertz-video-section {
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 20px;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: #fff;
    box-sizing: border-box;
}

/* --- 标题样式 --- */
.hertz-section-title {
    text-align: center;
    color: #003366;           /* 品牌深蓝 */
    font-size: 40px;
    font-weight: 700;
    margin-bottom: 40px;
    position: relative;
    padding-bottom: 15px;
    letter-spacing: 0.5px;
}

.hertz-section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background-color: #0056b3; /* 亮蓝色装饰线 */
    margin: 0 auto;
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    border-radius: 2px;
}

/* --- 视频网格布局 (电脑端 3列) --- */
.hertz-video-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
    align-items: stretch; /* 让卡片高度一致 */
}

/* --- 卡片样式 --- */
.hertz-video-card {
    background: #ffffff;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0,0,0,0.08);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    border: 1px solid #eeeeee;
    display: flex;
    flex-direction: column;
}

.hertz-video-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.12);
}

/* --- 视频容器 (16:9 比例) --- */
.hertz-video-wrapper {
    position: relative;
    padding-bottom: 56.25%; 
    height: 0;
    overflow: hidden;
    background-color: #000;
}

.hertz-video-wrapper iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border: 0;
}

/* --- 卡片文字内容 --- */
.hertz-card-content {
    padding: 25px;
    flex-grow: 1;
    text-align: left;
}

.hertz-card-content h3 {
    color: #003366;
    margin-top: 0;
    margin-bottom: 15px;
    font-size: 18px;
    font-weight: 700;
    border-bottom: 2px solid #0056b3;
    padding-bottom: 8px;
    display: inline-block;
}

.hertz-card-content p {
    color: #555;
    font-size: 14px;
    line-height: 1.6;
    margin: 0;
}

/* --- 移动端响应式 (手机端变 1列) --- */
@media screen and (max-width: 900px) {
    .hertz-video-grid {
        grid-template-columns: 1fr; /* 强制变1列 */
        gap: 40px;
    }
    
    .hertz-video-card {
        max-width: 500px; /* 限制手机上卡片最大宽度 */
        margin: 0 auto;
        width: 100%;
    }
}