JSFiddle - React, Tailwind, and code Playground

HTML

<div class="bkgAnimate">Foreground text</div>

CSS

.bkgAnimate {
    width: 300px; /*only for demo*/
    height: 200px; /*only for demo*/
    position: relative;
    z-index: 1; /* make a local stacking context */
}

.bkgAnimate:after {
    content: '';
    position: absolute;
    top:0;
    right: 0;
    bottom: 0;
    left: 0;
    background: url(http://dummyimage.com/300x200/ff00ff/ffffff.png&text=300+x+200) no-repeat;
    z-index: -1;  
    -webkit-animation: fontbulger  3s infinite;
    -moz-animation:    fontbulger  3s infinite;
    -ms-animation:     fontbulger  3s infinite;
}
@-webkit-keyframes fontbulger {
    0%   { opacity: 1; }
    30%  { opacity: 0.5; }
    100% { opacity: 1; }
}
@-moz-keyframes fontbulger  {
    0%   { opacity: 1; }
    30%  { opacity: 0.5; }
    100% { opacity: 1; }
}
@-ms-keyframes fontbulger  {
    0%   { opacity: 1; }
    30%  { opacity: 0.5; }
    100% { opacity: 1; }
}