Responsive design posts

I am trying to set up posts with pictures. I already write a code where the position of pictures is correct but only in the mobiles. Is there any CSS command which can I use?

  height: 100px;
  weight: 100px;
    
}
.image2{
  height: 100px;
  weight: 100px;
  position: relative;
  left: 135px;
  }```
I already use this ```Traversy Media only screen and (min-device-width: 601px) and (max-device-width: 768px)``` but it does not work out.
And of course, I have set up on my header 
```<meta name="viewport" content="width=device-width, initial-scale=1.0">```
Any advice how can I set up positioning of pictures of PCs?