body {
   background-color: white;
}

.wrapper {
    display: flex;
}

.quarter_box {
    width: 25%;
    background-color: lightgray;
    margin: 10px;
    padding: 2%;
}

.third_box {
    width: 33.333%;
    background-color: lightblue;
    margin: 10px;
    padding: 2%;
}

.half_box {
    width: 50%;
    background-color: lightpink;
    margin: 10px;
    padding: 2%;
}

.green_third_box {
    width: 33.333%;
    background-color: palegreen;
    margin: 10px;
    padding: 2%;
}

.twothirds_box {
    width: 66.666%;
    background-color: palegreen;
    margin: 10px;
    padding: 2%;
}

@media screen and (max-width:728px) {
    .wrapper{
        flex-direction: column;
    }

    .green_third_box,.half_box,.quarter_box,.third_box,.twothirds_box {
        width: auto;
    }
}