body {
    margin: 0 auto;
    padding: 0;
    max-width: 700px;
}

article img,
article video {
    display: block;
    margin: 10px auto;
    max-width: 400px;
}

article img {
    cursor: pointer;
}

article video {
    width: 100%;
}

h1 {
    color: #333;
}

.date {
    color: #888;
}

.mask {
    top: 0;
    left: 0;
    position: fixed;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, .3);
    display: flex;
    justify-content: center;
    /* 水平居中 */
    align-items: center;
    /* 垂直居中 */
    height: 100vh;
    /* 视窗高度 */
    margin: 0;
}

.lightbox {
}