hi @niti77,
Do you mean that your site has same width as 1366×768 even on screens with this resolution 1440×900 or higher. Catch Responsive theme is not fluid layout theme. It is boxed layout theme.
If you want it to be fluid layout, you can add following css code in “Appearance-> Customize-> Theme Options-> Custom CSS” box:
@media screen and ( min-width:1440px ) {
.site, #feature-slider .cycle-slideshow {
width: 100%;
}
#main {
width: 70%;
}
}
This will make the width 100% for screen sizes greater than 1440px width. For anything else related to the width, you will need to hire a customizer to do custom work and make it work for higher resolution screens as you like.
Please post in your site url too for further queries.
Regards,
Pratik