<div
     class="container-grid"
     style="background: orange; width: 500px; height: 250px;"
     >
    <div
         style="color: white; border-color: white; border-style: solid"
         >
      I'm center in the box
    </div>
</div>

/* Using Grid */

.container-grid {
    display: grid;
    place-content: center;
}