One way i'd do it is by warping those circles into another DIV than give that DIV a
width:100%; than since it is 4 circles make each one have
width:25%; so when the window shrinks so does the circles.
The only problem is if the screen gets too small the circles will become completely small if you set a fixed height than those circles will come it in a very narrow OVAL and you don't really want that.
If you are going to use media queries than use them at 50% after certain screen width to put 2 in a row.
otherwise there are methods to use
display:flex unfortunately I am not very familiar with flex