Code Run - Live Demo

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Controlling Flow inside Flex Container along Main Axis</title>
<style>
.flex-container {
    width: 80%;
    min-height: 300px;
    margin: 0 auto;
	font-size: 35px;
    /* Safari */
    display: -webkit-flex;
    -webkit-flex-direction: row-reverse;
    /* Standard syntax */
    display: flex;
    flex-direction: row-reverse;
    border: 5px solid purple;
}
.flex-container div {
	padding: 10px;
	-webkit-flex: 1; /* Safari 6.1+ */
	-ms-flex: 1; /* IE 10 */
	flex: 1; /* Standard syntax */
}
.item1 {
	background: red;
}
.item2 {
	background: Lightgreen;
}
.item3 {
	background: blue;
}
</style>
</head>
<body>
    <div class="flex-container">
        <div class="item1">Item 1</div>
        <div class="item2">Item 2</div>
        <div class="item3">Item 3</div>
    </div>
    <p><strong>Note:</strong> The Change value of flex-direction property from "row-reverse" to "row" to understand how this property works.</p>
</body>
</html>