flex grow w3schools code example
Example: flex grow
#content {
display: flex;
justify-content: space-around;
flex-flow: row wrap;
align-items: stretch;
}
.box {
flex-grow: 1;
border: 3px solid rgba(0,0,0,.2);
}
.box1 {
flex-grow: 2;
border: 3px solid rgba(0,0,0,.2);
}