Hello, @Kazi Sabit,
1. On my end the left side is also showing the same space as the right side and also when you will remove the border using the below solution of point no 2 then that gap issue will be resolved too as well.
2. Please copy and paste the below-given CSS code to XStore >> Theme Settings >> Theme Custom CSS and under Global Custom CSS and check back your site after removing the browser cache, It will remove the border you want.
.elementor-element.elementor-widget-et-advanced-tabs .et-advance-tabs .et-tabs-content {
border: 0 !important;
}
.et-advance-tabs.horizontal-style-3 .et-tabs-nav>ul .et-tab-nav {
border-bottom: 1px solid #e1e1e1 !important;
}
Regards 8Themes Team.