lidarr: main bg fix

CSS/themes/lidarr/plex.css

@@ -14,7 +14,7 @@
 /* LIDARR PLEX THEME */
 @import url(https://gilbn.github.io/theme.park/CSS/themes/lidarr/lidarr-base.css);
 :root {
-  --main-bg-color: url("https://raw.githubusercontent.com/gilbN/theme.park/master/Resources/blur-noise.png"), url("https://raw.githubusercontent.com/gilbN/theme.park/master/Resources/preset-light2.png");
+  --main-bg-color: url("https://raw.githubusercontent.com/gilbN/theme.park/master/Resources/blur-noise.png"), url("https://raw.githubusercontent.com/gilbN/theme.park/master/Resources/preset-light2.png") center center/cover no-repeat fixed;
   --modal-bg-color: url("https://raw.githubusercontent.com/gilbN/theme.park/master/Resources/blur-noise.png"), url("https://raw.githubusercontent.com/gilbN/theme.park/master/Resources/preset-light2.png") center center/cover no-repeat fixed; 
   --link-color: #FFEB3B; 
   --custom-buttons-color: radial-gradient(ellipse at center, #F44336 0%, #3F51B5 100%) center center/cover no-repeat fixed;