Responsive issues in Porto theme

It would be great if anyone can help. I am a beginner with Magento. I have few issues with the the following ip.(the web site is under construction). The slider images not displaying properly in PC / Mac. the mobile view is ok however, the logo appears very small and displayed in the left which I wanted to display on the top centre. I was looking into all the options but unable to find the issue. Thank you in advance.