Vertically center align ‘horizontal theme’

Please help me vertically center align my site https://www.anishaacharya.com/w/
My css appears as below. Do let me know if you need something else. Thanks!

/*
Theme Name: Hyku Photo Gallery
Theme URI: https://hyku.com/wp-themes/
Description: A horizontal scrolling theme for photos
Version: 1.0
Author: Josh Hallett
Author URI: https://hyku.com/

*/

body {
background: url('http:blah);
background-repeat: repeat;
font-size: 0px;
font-family: 'Lucida Grande', Verdana, Arial, Sans-Serif; text-align: left;
}
a {color: #ebebeb; text-decoration: none;}
a:hover {text-decoration: none; color: #666;}
#header {text-transform: uppercase; letter-spacing: 2px; margin: 0px 0 0 0px;}
#gallery {width: 29000px; margin: 0px 0px 0px 0px;}
#single-image {width: 100%; margin: 0px 0px 0px 0px;}
#photos {margin: 0px 0 0 0;}
.photo {display: inline; vertical-align: middle;}
.image {float: left; width: 1000px; vertical-align: middle;}
.meta {margin: 0px 0px 0px 0px; border-left: 0px dotted #666; padding: 0 0 0 0px; line-height: 0px; vertical-align: middle;}
h2 {font-size: 0px;}
.navigation {float: right; padding: 0px 0px 0 0; vertical-align: middle;}
.pagenavigation {clear: both; margin: 0px 0px 0 0px; vertical-align: middle;}