how to set background automatically with my screen height

html {
background: url(image.jpg) no-repeat center center fixed;
-webkit-background-size: cover;
-moz-background-size: cover;
-o-background-size: cover;
background-size: cover;

body {

  background-image: url("img_tree.gif");

  background-repeat: no-repeat;  
background-attachment: fixed;

background-position: top center;
background-size: contain;


how to reduce the size of my electron app

You can reduce the electron app size by packaging using electron-builder package.
PicArt is an electronjs app which I developed recently. It is built using reactJS.
Initially when I packaged the app using electron-packager the Window's build size was
around 98 MB.
Then I found this awesome boilerplate electron-react where they configured the
electron-builder to produced optimised build size.
After using those configuration setup, PicArt's build is now around 36 MB.