.obdelnik1{ 
width: 25%;
background-color: darksalmon;
padding: 5%;

}
@media screen and (max-width:900px){
    .obdelnik1{ 
        width: 100%;
        background-color: blueviolet;
        padding: 5%;}}



.obdelnik2{ 
    width: 25%;
    background-color: aqua;
    padding: 5%;
    }
    @media screen and (max-width:900px){
        .obdelnik2{ 
            width: 100%;
            background-color: gold;
            padding: 5%;}}


            .obdelnik3{ 
                width: 25%;
                background-color: indigo;
                padding: 5%;
                }
                @media screen and (max-width:900px){
                    .obdelnik3{ 
                        width: 100%;
                        background-color: red;
                        padding: 5%;}}

                        .obdelnik4{ 
                            width: 25%;
                            background-color: tomato;
                            padding: 5%;
                            
                            }
                            @media screen and (max-width:900px){
                                .obdelnik4{ 
                                    width: 100%;
                                    background-color: teal;
                                    padding: 5%;}}