@media screen and (min-width: 900px) {
    .content{
    display: flex;
    }

    .kolonka1{
    background-color: bisque;
    width: 25%;
    padding: 5%;
    }

    .kolonka2{
    background-color: cyan;
    width: 25%;
    padding: 5%;
    }

    .kolonka3{
    background-color: red;
    width: 25%;
    padding: 5%;
    }   

    .kolonka4{
    background-color: orangered;
    width: 25%;
    padding: 5%;
   }
}

@media screen and (max-width:900px) {
        .kolonka1{
        background-color: greenyellow;
        width: 100%;
        padding: 10%;
        }
    
        .kolonka2{
        background-color: orange;
        width: 100%;
        padding: 10%;
        }
    
        .kolonka3{
        background-color: blueviolet;
        width: 100%;
        padding: 10%;
        }   
    
        .kolonka4{
        background-color: lightcoral;
        width: 100%;
        padding: 10%;
       }
}