<!doctype html>
<html>
    <head>
        <meta charset="utf-8">
        <style>
            .bar {
                width: 400px;
                height: 100px;
            }
            .box {
                display: inline-block;
                width: 100px;
                height: 100px;
                border: 0px;
                background-image: linear-gradient(to bottom left, red 50%, transparent 50%);
            }

        </style>
    </head>
    <body>
        <div class="bar">
            <div class="box"></div><div class="box"></div><div class="box"></div><div class="box"></div>
        </div>
        <div class="bar">
            <div class="box"></div><div class="box"></div><div class="box"></div><div class="box"></div>
        </div>
    </body>
</html>

