2 CSS Issues for Mobile

Hi Guys,

I have 2 issues for css on mobile. Can anyone help me with the following codes:

– A css code to center images only on mobile? On the site it have to be alligned to left but on mobile it have to be centered cause of layout problems.

– a css code to hide an image on mobile. Now 1 image wont fit well on mobile but it fit well on the site so i want to hide the images on mobile only.

Thanx already!!