    <div class="demo-item">
        <p class="demo-desc">竖排flex</p>
        <div class="demo-block">
            <div class="ui-row-flex ui-whitespace ui-row-flex-ver">
                <div class="ui-col">1/2</div>
                <div class="ui-col">1/2</div>
            </div>
            <br/>
            <div class="ui-row-flex ui-whitespace ui-row-flex-ver">
                <div class="ui-col ui-col-3">3/4</div>
                <div class="ui-col">1/4</div>
            </div>
        </div>
    </d