div right and left
#container {
display: flex; /* establish flex container */
flex-direction: row; /* default value; can be omitted */
flex-wrap: nowrap; /* default value; can be omitted */
justify-content: space-between; /* switched from default (flex-start, see below) */
background-color: lightyellow;
}
#container > div {
width: 100px;
height: 100px;
border: 2px dashed red;
}