uk-grid

<div class="uk-grid">
    <div class="uk-width-1-1">
        <div class="uk-panel uk-panel-box">1-1</div>
    </div>
</div>
<div class="uk-grid" >
    <div class="uk-width-large-1-6 uk-width-medium-1-4 uk-width-small-1-2">
        <div class="uk-panel uk-panel-box">1-4</div>
    </div>
    <div class="uk-width-large-1-6 uk-width-medium-1-4 uk-width-small-1-2">
        <div class="uk-panel uk-panel-box">1-4</div>
    </div>
    <div class="uk-width-large-2-6 uk-width-medium-1-4 uk-width-small-1-2">
        <div class="uk-panel uk-panel-box">1-4</div>
    </div>
    <div class="uk-width-large-2-6 uk-width-medium-1-4 uk-width-small-1-2">
        <div class="uk-panel uk-panel-box">1-4</div>
    </div>
</div>

preview