flexbox grid under centered flex item - html

Question

I would like an intro section on the left side of a .container and a side bar on the right.
On the left side underneath the .intro section I want there to be four divs equally spaced like a grid.
I'm having problems with getting the "grid set up". I think part of the problem is that the parent has some flexbox attribute effecting the children.
Requirement : The intro section should be centered in the .left-side and the "grid" should not be centered the boxes should take up as much space as necessary to fit 2 on a row with margins in between. The .intro should be 80 percent of the width of the leftside.
I don't want to do any major changes to the structure this is just a small sample of how my project is set up.
.container{
width: 80%;
margin: 0 auto;
display: flex;
}
.left-side{
flex:8;
display: flex;
justify-content:center;
flex-wrap: wrap;
}
.side-bar{
flex: 2;
height: 100vh;
background: powderblue;
}
.intro{
flex:3;
width:80%;
height: 300px;
background: skyblue;
}
.box{
background: red;
width: 45%;
height: 100px;
flex:4;
border:1px solid orange;
}
<div class="container">
<div class="left-side">
<div class="intro">
intro
</div>
<div class="recent">
<div class="box">1</div>
<div class="box">2</div>
<div class="box">3</div>
<div class="box">4</div>
</div>
</div>
<div class="side-bar">
sidebar
</div>

Answer 1

Flex items can also be flex containers. This enables you to nest multiple containers, with flex-direction: row or column, in a larger container.
For your layout, you can build a column consisting of two flex items. The first item (.intro) has 80% width and can be centered horizontally. The second item (.recent) can be a flex container with four items arranged in a 2x2 grid.
.container {
width: 80%;
margin: 0 auto;
display: flex;
justify-content: center;
height: 100vh;
}
.left-side {
flex: 4;
display: flex;
flex-direction: column;
}
.side-bar {
flex: 1;
background: powderblue;
}
.intro {
flex: 3;
height: 300px;
width: 80%;
margin: 0 auto;
background: skyblue;
}
.recent {
display: flex;
flex-wrap: wrap;
background-image: url("http://i.imgur.com/60PVLis.png");
background-size: contain;
}
.box {
margin: 5px;
flex-basis: calc(50% - 10px);
height: 100px;
box-sizing: border-box;
background: red;
}
body { margin: 0; }
<div class="container">
<div class="left-side">
<div class="intro">intro</div>
<div class="recent">
<div class="box">1</div>
<div class="box">2</div>
<div class="box">3</div>
<div class="box">4</div>
</div>
</div>
<div class="side-bar">
sidebar
</div>
</div>