style1.css

*{
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}
body{
    font-family: Arial, Helvetica, sans-serif;

}
.item{
    width: 100px;
    height: 100px;
    background: blue;
    color: antiquewhite;
    margin: 10px;
    display:flex;
    justify-content: center;
    align-items: center;
}
.Container-1{
    height: 400px;
    display: flex;
    /*justify-content:space-between;

    background-color: aquamarine;
    /* align-items: flex-start; */
    /* flex-direction:column;
    align-items:flex-start; */
    background-color: black;
    /* flex-wrap: wrap; */
} 
.item:nth-last-of-type(1){
    /* align-self:flex-start */
    /* flex-basis: 200px; */
    flex-grow: 2;
}
.item:nth-last-of-type(2){
    /* order:3 */
    flex-grow: 2;
}
.item:nth-last-of-type(3){
    /* align-self: flex-end; */
    flex-grow: 2;
}