<body style="-webkit-writing-mode: vertical-lr">
<div style="-webkit-logical-width: 600px; -webkit-margin-after:50px">
    <span style="-webkit-padding-start: 15px; -webkit-padding-end:15px; -webkit-padding-before:5px; -webkit-padding-after: 5px; font-size: 48px; background-color:blue">
    <span style="
        -webkit-padding-start: 15px; -webkit-padding-end:15px;
        font-size: 48px;
        background-color: lightyellow;
        -webkit-border-radius: 10px;
        border: 5px solid green;
        line-height: 1.5;
    ">
        This sentence is too long to fit on a single line.
    </span></span>
</div>