BG elements

<div className="uk-bg-elements">
  <img src={roses.src} width={roses.width} height={roses.height} alt="" aria-hidden="true" loading="lazy" className="uk-bg-element" />
  <img src={cake.src} width={cake.width} height={cake.height} alt="" aria-hidden="true" loading="lazy" className="uk-bg-element uk-bg-element--end" />
  <section className="uk-section">…</section>
  <section className="uk-section uk-section-muted">…</section>
</div>

--uk-bg-element-top        10%     how far down the wrapper (the height of all its sections)
--uk-bg-element-bottom     10%     or from its end, with uk-bg-element--bottom
--uk-bg-element-out        0.25    the share that falls off the screen
--uk-bg-element-max        560px   the width's ceiling on a very wide screen
--uk-bg-element-container  the container's width, for any size but small, large and x-large (read by themselves)

<section className="uk-section uk-bg-net uk-bg-glow">…</section>

--uk-bg-at          100% 0%  the corner they start from
--uk-bg-net-size    48px     the net's square
--uk-bg-net-color            its lines
--uk-bg-glow-color           the patch's colour