<div class="uk-section uk-section-default uk-flex uk-flex-middle" uk-height-viewport>
    <div class="uk-width-1-1">
        <div class="uk-container">

            <div class="uk-child-width-1-4@m uk-text-center" uk-grid>
                <div>

                    <div class="uk-background-default uk-height-medium"></div>
                    <h2 class="uk-h5">Default</h2>

                </div>
                <div>

                    <div class="uk-background-muted uk-height-medium"></div>
                    <h2 class="uk-h5">Muted</h2>

                </div>
                <div>

                    <div class="uk-background-primary uk-height-medium"></div>
                    <h2 class="uk-h5">Primary</h2>

                </div>
                <div>

                    <div class="uk-background-secondary uk-height-medium"></div>
                    <h2 class="uk-h5">Secondary</h2>

                </div>
            </div>

        </div>
    </div>
</div>