Bootstrap 4.1 Cards Styling - css

Question

I have this code:
<div class="container">
<div class="row">
<div class="col-md-4">
<div class="card">
<div class="card-header">Employee Information</div>
<div class="card-body">
<table class="table table-borderless">
<tbody>
<tr>
<td scope="row">First Name: </td>
<td>{{ $employee->first_name }}</td>
</tr>
<tr>
<td scope="row">Last Name: </td>
<td>{{ $employee->last_name }}</td>
</tr>
<tr>
<td scope="row">ID Number: </td>
<td>{{ $employee->id_number }}</td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
<div class="col-md-8">
<div class="card">
<div class="card-header">External Training Records</div>
<div class="card-body">
External Training Records:
</div>
</div>
</div>
<div class="col-md-8 offset-md-4">
<div class="card">
<div class="card-header">Clients</div>
<div class="card-body">
Clients:
</div>
</div>
</div>
<div class="col-md-8 offset-md-4">
<div class="card">
<div class="card-header">Site</div>
<div class="card-body">
Sites
</div>
</div>
</div>
</div>
</div>
https://jsfiddle.net/aq9Laaew/206869/
I would like the two sections on the right (external training and clients) to be underneath one another (when on a desktop). How does one do that in Bootstrap?
I know very little about front-end development. This is a learning curve for me.

Answer 1

To achieve that using Bootstrap layout utility classes, all you need is to place all your cards into one column, instead of adding a row for each card:
<div class="row">
<div class="col-lg-4">
... your left column card here...
</div>
<div class="col-lg-8">
... rest of your cards here...
</div>
</div>
Working example:
.row {
background: #f8f9fa;
}
.col {
border: solid 1px #6c757d;
}
.card {
margin-top: 15px;
}
.card + .card:last-child {
margin-bottom: 15px;
}
<link href="https://stackpath.bootstrapcdn.com/bootstrap/4.1.0/css/bootstrap.min.css" rel="stylesheet"/>
<script src="https://code.jquery.com/jquery-3.3.1.slim.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.14.0/umd/popper.min.js"></script>
<script src="https://stackpath.bootstrapcdn.com/bootstrap/4.1.0/js/bootstrap.min.js"></script>
<link href="https://stackpath.bootstrapcdn.com/font-awesome/4.7.0/css/font-awesome.min.css" rel="stylesheet"/>
<div class="container">
<div class="row">
<div class="col-lg-4 col-md-5">
<div class="card">
<div class="card-header">Employee Information</div>
<div class="card-body">
<table class="table table-borderless">
<tbody>
<tr>
<td scope="row">First Name: </td>
<td>Jane</td>
</tr>
<tr>
<td scope="row">Last Name: </td>
<td>Doe</td>
</tr>
<tr>
<td scope="row">ID Number: </td>
<td>123456789123</td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
<div class="col-lg-8 col-md-7">
<div class="card">
<div class="card-header">External Training Records</div>
<div class="card-body">
External Training Records:
</div>
</div>
<div class="card">
<div class="card-header">Clients</div>
<div class="card-body">
Clients:
</div>
</div>
<div class="card">
<div class="card-header">Site</div>
<div class="card-body">
Sites
</div>
</div>
</div>
</div>
</div>
Please note your current question title doesn't relate too well to the actual problem. You're basically asking a layout utility question. Whatever you place in your layout has no relevance for solving/answering it.

Answer 2

I think this is what you want
<div class="container">
<div class="row">
<div class="col-md-4">
<div class="card">
<div class="card-header">Employee Information</div>
<div class="card-body">
<table class="table table-borderless">
<tbody>
<tr>
<td scope="row">First Name: </td>
<td>Jane</td>
</tr>
<tr>
<td scope="row">Last Name: </td>
<td>Doe</td>
</tr>
<tr>
<td scope="row">ID Number: </td>
<td>123456789123</td>
</tr>
</tbody>
</table>
</div>
</div>
</div>
<div class="col-md-8">
<div class="card">
<div class="card-header">External Training Records</div>
<div class="card-body">
External Training Records:
</div>
</div>
<div class="card">
<div class="card-header">Clients</div>
<div class="card-body">
Clients:
</div>
</div>
</div>
<div class="col-md-8 offset-md-4"></div>
<div class="col-md-8 offset-md-4">
<div class="card">
<div class="card-header">Site</div>
<div class="card-body">Sites</div>
</div>
</div>
</div>
</div>