How to set common CSS for images to maintain same UI look while working with mobile and tablets

Hello All,
This topic is not related with Ionic but presently am working in Ionic V1 and developing an app for mobile and tablet.but i have faced some challenges while setting size to images for my menu in bottom of my view.considering mobile platform if i set height and width for images in pixels ,then these images in tablet look smaller.again the if i set first for tablet the image looks bigger.If i set image height and width in VH and VW,spacing becomes issue between my image and text(as it is a menu).so i would be grateful if anyone could share their experience of handling such issues.

Thank You,
Siba Prasad