How to fix meaningless white space in video frame?

Question

Screenshot Hello everyone, I need your help to fix this interesting white space. Why does it look this?

Answer 1

Set the border-width to an even number, so instead of this:

#video_1 {
    /* ... */
    border-radius: 15px;
    border-style: solid;
    border-width: 5px;
    /* ... */
}

Instead use something like 4px instead of 5px:

#video_1 {
    /* ... */
    border-radius: 15px;
    border-style: solid;
    /* like this */
    border-width: 4px;
    /* ... */
}