Hi harun,
To hide the Banner Slider on mobile View then please go to 'Appearance > Customizer > Additional CSS' and paste the below Custom CSS code.
@media (max-width: 575px) {
.featured-section .featured-slider {
display: none;
}
}
To make the Slider Posts only 3 then you can show the post through category where you can assign only desired 3 posts.
Note: If you are using the High resolution images in your site then you can use the use the compressed images having the same quality of images. There are various application and Websites where you can compress the images size without loosing the quality of images. We recommend you to use Compressor.io. From it you can compress the images without loosing quality. It will definitely helps to reduce the Page load time.
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