How to reduce the size of a video on a site from YouTube so that the mobile version does not suffer?

Question

Video

Hello!
site baikal-gavan03 I inserted a
video from YouTube into the site in the following way:
html:

in css code for adapting the video:
.video-responsive {
position:relative;
padding-bottom:56.25%;
padding-top:30px;
height:0;
overflow:hidden;
}
.video-responsive iframe,
.video-responsive object,
.video-responsive embed {
position: absolute;
top: 0;
left: 0;
width: 100%
height: 100%;
}
Now the mobile version is displayed normally, but on the site the video is too large, it does not fit on the screen, I would like to reduce it by half. How can I do that? Thank you!