<style>
    div.container {
        -webkit-logical-width: 8em;
        font: 20px ahem;
        -webkit-font-smoothing: none;
        outline: thin dashed lightblue;
        -webkit-ruby-position: after;
        margin: 8px 0;
    }

    span.emphasis {
        -webkit-text-emphasis-style: "w";
        -webkit-text-emphasis-color: purple;
    }

    ruby {
        color: blue;
    }

    rt {
        color: orange;
    }
</style>
<div style="float: left;">
    <div class="container">
        xxxxx xx <ruby>xxxx<rt>yyy</rt></ruby> xxx xxx xxxx
        <ruby>xxxxx<rt>y<br>y</rt></ruby> <span class="emphasis">xx</span>
        xxx xxxx
    </div>
    <div class="container" style="-webkit-writing-mode: vertical-lr;">
        xxxxx xx <ruby>xxxx<rt>yyy</rt></ruby> xxx xxx xxxx
        <ruby>xxxxx<rt>y<br>y</rt></ruby> <span class="emphasis">xx</span>
        xxx xxxx
    </div>
</div>
<div style="float: left; margin-left: 8px;">
    <div class="container" style="-webkit-writing-mode: horizontal-bt;">
        xxxxx xx <ruby>xxxx<rt>yyy</rt></ruby> xxx xxx xxxx
        <ruby>xxxxx<rt>y<br>y</rt></ruby> <span class="emphasis">xx</span>
        xxx xxxx
    </div>
    <div class="container" style="-webkit-writing-mode: vertical-rl;">
        xxxxx xx <ruby>xxxx<rt>yyy</rt></ruby> xxx xxx xxxx
        <ruby>xxxxx<rt>y<br>y</rt></ruby> <span class="emphasis">xx</span>
        xxx xxxx
    </div>
</div>