html-код
<!DOCTYPE html>
<html lang="uk">
<head>
<link rel="stylesheet" type="text/css" href="css/style.css">
<title>My site</title>
<meta charset="UTF-8">
</head>
<body>
<div class="a">a</div>
<div class="e">
<div class="c">c</div>
<div class="d">d</div>
</div>
<div class="b">b</div>
</body>
</html>
css-код
.a{background-color:red;
width: 100%;
height: 100px;
}
.b{background-color:green;
width: 100%;
height: 200px;
}
.c{background-color:yellow;
width: 40%;
}
.d{background-color:blue;
width: 40%;
}
.e {display: flex;
}