how increase space for a video on front page?

Hello

I would like to increase the space for the video background plugin video on my static front page.

How to do this?

I have the css style below for the twenty-thirteen child theme. Can I change or add code to this to increase the space for the video?

Cheers Geoff

.site {
max-width: 100%;
width: 100%;
}

.vidbg-container {
overflow: visible !important;
}

.site-header{
background: rgba(f, 0, 0, 0) url("https://geoff-ideas.co.uk/wp-content/uploads/2016/01/cropped-debussy-1-1.jpg") no-repeat scroll center top / 1600px auto !important;
position: relative;
max-width: 100%;
width: 100%;
max-height: 120px;
z-index: 9999;
}

.navbar {
background-color: #ffffff;
margin: 0 auto;
max-width: 1600px;
width: 100%;
position: fixed;
top: 20px;
z-index: 999;
}

.main-navigation li a {
color: red;
font-weight: bold;
}