*{
    box-sizing: border-box;
}
body{
    margin: 0;
    background-color: lemonchiffon;
    line-height: 1.4;
}
.container{
    max-width: 960px;
    margin: 0 auto;
    outline: 3px dotted lightseagreen;
}
.row{
    display: flex;
}
.flex-item{
    flex-basis: 200px;
    height: 150px;
}
.one{
    background-color: lightgoldenrodyellow;
    outline: 3px dotted lightseagreen;
    flex-grow: 15;
}
.two{
    background-color: lightgoldenrodyellow;
    outline: 3px dotted lightseagreen;
    flex-grow: 2;
}
.three{
    background-color: lightgoldenrodyellow;
    outline: 3px dotted lightseagreen;
}