*{
    box-sizing: border-box;
}
body{
    margin: 0;
    background-color: lightgray;
    line-height: 1.4;
}

.container{
    max-width: 960px;
    margin: 0 auto;
    outline: 3px dotted red;
}

.row{
    display: flex;
}

.flex-item{
    flex-basis: 50px;
    height: 150px;
}

.one{
    background-color:tomato;
    flex-grow: 1;
}
.two{
    background-color: cadetblue;
    flex-grow: 1;
}
.three{
    background-color: rebeccapurple;
    flex-grow: 1;
}


/*********************************************************
                Header
*********************************************************/

header {
    overflow: hidden;
    background-color: #333;
    display: flex;
    color: white;
}

header h1 {
    text-align: center;
    color: white;
}

header img {
    width: 75px;
}