Flex-flow: Column Wrap, In A Flex Box Causing Overflow Of Parent Container

I have this scenario: https://jsfiddle.net/b6zcdgf7/ When using .section.vert the .box elements overflow the section. Is there anything i can do to prevent having to set a width o

Solution 1:

Change the flex-wrap to nowrap

.section.vert{
  flex-direction:column;
  flex-wrap: nowrap;
  outline: 3px dashed green;

}

Fiddle

Snippet

.container{
  display:flex;
  height:3em;
  border:solid thin blue;
}
.section{
  border:solid thin gray;
  display:flex;
}
.section.horiz{
  
}

.section.vert{
  flex-direction:column;
  flex-wrap: nowrap;
  outline: 3px dashed green;

}

.box{
  border:solid thin red;
  width:1em;
  height:1em;
}

<divclass="container"><divclass="section horiz"><divclass="box"></div><divclass="box"></div></div><divclass="section horiz"><divclass="box"></div><divclass="box"></div></div><divclass="section horiz"><divclass="box"></div></div><divclass="section vert"><divclass="box"></div><divclass="box"></div><divclass="box"></div><divclass="box"></div></div></div>