How to add content over multiple images?

I have a web page in which I have used css cross-fade animation to fade between two background images. Now, I need to add same content (logo and buttons) above both the images. However, this content is visible only for the first image and not the second. This is my code:

index.html

<div id="bgimg">
    <div class="bgimg-container">
      <div id="hero">
        <div class="bgimg-container">

            My content here


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

style.css

    #bgimg{
      display: table;
      background: url(../img/2.jpg);
      width:100%;
      height:100vh;
      background-position: top center;
      background-size: cover;
      background-repeat: no-repeat;
    }

    #hero {
    display: table;
    width: 100%;
    height: 100vh;
    background: url(../img/1.jpg);
    background-position: top center;
    background-size: cover;
    background-repeat: no-repeat;


    animation-name: cf3FadeInOut;
    animation-timing-function: ease-in-out;
    animation-iteration-count: infinite;
    animation-duration: 7s;
    animation-direction: alternate;
    }

    @keyframes cf3FadeInOut {
    0% {opacity:1;}
    45% {opacity:1;}
    55% {opacity:0;}
    100% {opacity:0;}
    }

    @media (min-width: 1024px) {
      #hero, #bgimg {
        background-attachment: fixed;
      }
    }

    #hero .hero-logo {
      margin: 20px;
    }

    #hero .hero-logo img {
      max-width: 100%;
    }


    #hero .hero-container {
      background: rgba(0, 0, 0, 0.8);
      display: table-cell;
      margin: 0;
      padding: 0;
      text-align: center;
      vertical-align: middle;
    }
    #bgimg .bgimg-container {
      background: rgba(0, 0, 0, 0.8);
      display: table-cell;
      margin: 0;
      padding: 0;
      text-align: center;
      vertical-align: middle;
    }

I've exhausted myself trying to figure it out. New here, please help.

Here you have a working example, maybe can use this to modify your code;

@keyframes cf3FadeInOut {
  0% {
    opacity: 1;
  }
  45% {
    opacity: 1;
  }
  55% {
    opacity: 0;
  }
  100% {
    opacity: 0;
  }
}

.img-container,
.bg-img-1,
.bg-img-2,
.content {
  height: 100vh;
  width: 100vw;
}

.img-container {
  position: relative;
}

.bg-img-1 {
  background-image: url('https://images.pexels.com/photos/1509428/pexels-photo-1509428.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940');
  background-size: cover;
  position: absolute;
}

.bg-img-2 {
  background-image: url('https://images.pexels.com/photos/886465/pexels-photo-886465.jpeg?auto=compress&cs=tinysrgb&dpr=2&h=650&w=940');
  position: absolute;
    background-size: cover;
  animation-name: cf3FadeInOut;
  animation-timing-function: ease-in-out;
  animation-iteration-count: infinite;
  animation-duration: 3s;
  animation-direction: alternate;
}

.content {
  background-color: rgba(0,0,0,0.5);
  color: #fff;
  position: absolute;
  display: flex;
  justify-content: center;
  align-items: center;
}

<div class="img-container">
  <div class="bg-img-1"></div>
  <div class="bg-img-2"></div>
  <div class="content">
    <div>
      hello <button>world</button>
    </div>
  </div>
<div>