My positioning of certain items on my web page keep moving slightly when i develop them on a big screen and display on a small screen they are out of position slightly, and vice versa.

this never happened me before but this is also the first site i am developing in asp.net here's my CSS 

```
#backb{
  position:absolute;
  left :22%;
  bottom:10%;
 }

#backf{
  position:absolute;
  left :12%;
  bottom:0%;
 }

#avatar{
  position:absolute;
  left :55%;
  bottom:45%;
 }

```