<div class="kv-grid">
    <div class="grid-child"></div>
    <div class="grid-child">E<sub>1</sub></div>
    <div class="grid-child">E<sub>1</sub></div>
    <div class="grid-child">!E<sub>1</sub></div>
    <div class="grid-child">!E<sub>1</sub></div>
    <div class="grid-child"></div>
    <div class="grid-child">E<sub>2</sub></div>
    <div class="grid-child" id="4"></div>
    <div class="grid-child" id="8"></div>
    <div class="grid-child" id="7"></div>
    <div class="grid-child" id="3"></div>
    <div class="grid-child">!E<sub>4</sub></div>
    <div class="grid-child">E<sub>2</sub></div>
    <div class="grid-child" id="12"></div>
    <div class="grid-child" id="16"></div>
    <div class="grid-child" id="15"></div>
    <div class="grid-child" id="11"></div>
    <div class="grid-child">E<sub>4</sub></div>
    <div class="grid-child">!E<sub>2</sub></div>
    <div class="grid-child" id="10"></div>
    <div class="grid-child" id="14"></div>
    <div class="grid-child" id="13"></div>
    <div class="grid-child" id="9"></div>
    <div class="grid-child">E<sub>4</sub></div>
    <div class="grid-child">!E<sub>2</sub></div>
    <div class="grid-child" id="2"></div>
    <div class="grid-child" id="6"></div>
    <div class="grid-child" id="5"></div>
    <div class="grid-child" id="1"></div>
    <div class="grid-child">!E<sub>4</sub></div>
    <div class="grid-child"></div>
    <div class="grid-child">!E<sub>3</sub></div>
    <div class="grid-child">E<sub>3</sub></div>
    <div class="grid-child">E<sub>3</sub></div>
    <div class="grid-child">!E<sub>3</sub></div>
    <div class="grid-child"></div>
</div>